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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
×
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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Suggested Citation:"Chapter 3 - Findings." National Academies of Sciences, Engineering, and Medicine. 2010. Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles. Washington, DC: The National Academies Press. doi: 10.17226/14458.
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This chapter is based on an analysis of the information and literature presented in the preceding Chapter, to obtain an understanding of the impacts resulting from the changes in Canadian truck size and weight regulations on trucking in Canada, and in cross-border trucking. This consists of the following steps: • Economic impacts; • Estimates of the changes in truck fleet size and the mix of configurations; – For the domestic fleet, and as it was affected by the regu- lations in U.S. Border States. – Impacts that were not anticipated; – Cost recovery; and – Changes in compliance and enforcement; • U.S. truck size and weight regulation; and • Application of Canadian experience to the United States. 3.1 Economic Impacts The CCMTA/RTAC Committee on Vehicle Weights and Dimensions commissioned a study of the potential economic impacts of changes to size and weight regulations in 1986 and 1987—after completion of the Vehicle Weights and Dimen- sions Study but before the M.o.U. was finalized—to assist in the formulation of the M.o.U. (62). This study included three candidate regulatory scenarios: Scenario A considered an 18.7-m (61-ft) semitrailer, doubles with a 19.0-m (62-ft 4-in.) box length, and 7-axle B-trains. Scenario B considered a 16.8-m (55-ft) semitrailer, doubles with a 19.0-m (62-ft 4-in.) box length, and 8-axle B-trains. Scenario C considered an 18.7-m (61-ft) semitrailer, doubles with a 20.8-m (68-ft 3-in.) box length, and 8-axle B-trains. All scenarios included a tridem semitrailer and used axle and gross weights rather similar to those that ultimately appeared in the M.o.U. Scenarios A and C each resulted in estimated annual net benefits of about $220 million in 1985 Canadian dollars, where the net benefit was the ultimate trucking productivity benefit less increased road and bridge costs after transition. Scenario B resulted in an estimated net benefit of about $165 million, and the difference from the other two scenarios was principally due to the shorter semitrailer length. The two national railways together estimated annual losses ranging from $108 to $192 million for the three scenarios. The study considered these to be reasonable estimates, on the assumption that other changes would not occur. A survey of carriers and shippers showed that they would immediately take advantage of whatever regulatory scenario would be put in place. For other impacts, it was concluded there would be a mod- est benefit to highway safety, that railways would develop new equipment to facilitate intermodal operations, and that there would be small impacts on energy use, the environment, and traffic, even if the full diversion from rail occurred. A second study was commissioned by the Task Force on Ve- hicle Weights and Dimensions Policy, 5 years after the M.o.U. was put in place. It essentially followed the form of the previous study,exceptitdidnotconsider the impacts on the railways (63). This study estimated annual net benefits of about $142 mil- lion for 1992, $180 million for 1997, and $222 million for 2002, in 1992 Canadian dollars, for operations on the Cana- dian National Highway System. It was estimated the actual net benefit would be about double if operations on other high- ways were also considered. The net transportation cost bene- fit for the 15 years from 1988 through 2002 was 328 times the $5.7 million cost of the research project. The second study was made more difficult by the presence of significant confounding factors. The M.o.U. was imple- mented essentially concurrently with three other events: • Deregulation of trucking in Canada in 1987, • Periods of recession from 1987 through to 1995, and • The free trade agreement between Canada and the United States in 1988, which was supplanted by the NAFTA in 1994. C H A P T E R 3 Findings 26

27 These events caused changes to carriers, the amount of freight, and freight flows that affected the truck fleet size of the preferred configurations. As each occurred essentially simul- taneously, it was rather difficult to disaggregate the effects of the M.o.U. from these other effects. However, it is probably likely that the entry and growth of new, agile carriers acceler- ated the introduction of M.o.U. configurations into the fleet. The railways were opposed to the M.o.U. as a matter of principle. However, the railways tend to move bulk and heavy freight over long distances, and trucks move anything over short and medium distances. Since the M.o.U., the railways have made substantial changes, acquiring U.S. lines, aban- doning unprofitable branch lines in Canada, sharing track, and developing intermodal service into the single fastest growing transportation sector. Interestingly, the railways were actually the largest single early purchasers of new M.o.U. configurations, buying one standard design of container chas- sis for all their terminals across the country. 3.2 Changes in Truck Fleets 3.2.1 Domestic Fleet, 1999 The 1999 National Roadside Survey provides a wealth of detailed insight into the truck fleet in Canada (65). The data- base contains information on truck configurations, weights, dimensions, payloads, and trips from a survey conducted on the National Highway System, in addition to significant links. It provides a good national view of trucking on major high- ways but may significantly underestimate local trips in and around urban areas, and in rural areas. A total of 311 distinct vehicle configurations were found during the 1999 National Roadside Survey (65). Table 1 pres- ents the breakdown of these. All possible M.o.U. configura- tions of straight truck, tractor, and tractor-semitrailer were found, but only 12 of 14 possible truck-trailer combinations, six of eight possible A-train configurations, six of 12 possible B-train configurations, and five of eight possible C-train con- figurations, were found. The tractor-tandem semitrailer (T12-2) was the most com- mon configuration in all provinces, by a wide margin, and made up 40.05% of all truck trips in Canada. The proportion of trips varied from 29.44% in the Atlantic Provinces to 51.90% in Manitoba and 45.62% in Ontario, reflecting regional differ- ences in freight and routes. The T12-12 is a general purpose vehicle for carriage of payloads of moderate and low density and is fully compatible with the U.S. Interstate system. Tandem semitrailers were also towed by a tractor with a single drive axle (T11-2), which was the ninth most common configuration, making up 1.42% of all trips. Two- and 3-axle straight trucks (S11 and S12) were the sec- ond and fourth most common configurations, and made 16.44 and 6.20% of all trips in Canada, respectively. These are primarily local use vehicles in both urban and rural areas. The tractor-tridem semitrailer (T12-3) and tri-axle semi- trailer (T12-12) were the third and sixth most common con- figurations, respectively, and together they made 13.70% of all trips in Canada. Together these configurations made about 12% to 16% of all trips in the four western provinces and Québec, about 10% in Ontario, and just over 28% in the At- lantic Provinces. These are general purpose configurations for payloads of moderate weight. The tridem semitrailer has three equally spaced load-sharing axles, while the tri-axle semi- trailer has a single liftable axle mounted ahead of a tandem axle group. Tridem semitrailers did not exist in the four west- ern provinces prior to the M.o.U., but now clearly are an im- portant configuration. Tridem semitrailers were legal in the six eastern provinces prior to the M.o.U., but were not com- mon as the tri-axle semitrailer had a higher allowable gross weight. The lower proportion of tridem semitrailers in On- tario and Québec is partly due to the tri-axle semitrailers that were operating prior to the M.o.U., particularly in specialized body styles like tank and dump applications, and also partly due to the availability of quad-axle semitrailers and 5- and 6-axle semitrailers in Ontario, which allow even higher pay- loads. All six eastern provinces have now set schedules to phase out tri-axle semitrailers, and these vehicles will gradu- ally disappear over the next 15 years or so, though the self- steer tri-axle recently allowed in Ontario may continue to serve a niche market in that province. The 8-axle B-train (T12-3-B2) is the principal vehicle for heavy haul across Canada. It was the fifth most common con- figuration, and made 5.45% of all trips. This configuration made about 8% of trips in British Columbia, 14% to 17% in Alberta, Saskatchewan and Manitoba, only just over 3% in Ontario and Québec, and 10% in the Atlantic Provinces. It is clearly the vehicle of choice for heavy haul in the four west- ern provinces and in the four eastern provinces, where it did not exist prior to the M.o.U. The proportion is low in Ontario because many carriers have opted for a 5- or 6-axle semi- trailer over an 8-axle B-train. The allowable gross weight and overall length of this B-train was restricted in Québec for routes off freeways, and consequently it offered little benefit for most carriers over the quad-axle semitrailer. Configuration Top 35 All M.o.U. Straight Truck 4 12 2 Bobtail Tractor 1 4 2 Tractor-semitrailer 18 106 6 Truck-trailer 5 53 10 A-train 5 61 6 B-train 2 57 6 C-train 0 18 5 Total 35 311 37 Table 1. Number of configurations.

The quad or self-steer quad semitrailer (T12-13) was adopted by Québec as a heavy haul vehicle in 1991. It is also commonly used between Ontario and Québec, and some are also operating by permit in New Brunswick. It can also travel as a tridem semitrailer in other provinces if its liftable axle is raised. The quad was the seventh most common configura- tion, responsible for 4.56% of all trips. It is the principal heavy haul semitrailer in Québec, where it was responsible for 11.95% of all trips, and is also significant in Ontario where it was responsible for 3.02% of all trips. The bobtail tandem tractor was the eighth most common configuration, responsible for 2.50% of all trips. The pusher (or tri-axle) straight truck (S112) was the tenth most common configuration, responsible for 1.06% of all trips. This is essentially an Ontario configuration, where it made 1.89% of all trips, but was also found in Québec and the Atlantic Provinces, where it can operate with its liftable axle raised as a three-axle straight truck. The single axle is com- monly a rigid liftable axle, though some of these vehicles are fitted with a self-steering axle that does not need to be lifted when the vehicle makes a turn. The M.o.U. introduced the tridem semitrailer and the 8-axle B-train, and these are now the third and fifth most common configurations across Canada. The impact is more striking in the four western provinces because these provinces have all adopted the M.o.U. as their form of regulation in 1989. Change was inhibited in the six eastern provinces due to Ontario’s refusal to increase the semitrailer length to 16.20 m (53 ft) and doubles combination overall length to 25 m (82 ft) until 1994. While the tridem semitrailer replaced many of the former tri- axle semitrailers, the availability of the quad and self-steer quad semitrailer at a 16.20-m (53-ft) length has inhibited its growth, as these alternatives provide a greater payload for some com- modities, and they can still bring back a load that would nor- mally travel in a tandem semitrailer. Change in the fleet within the Prairie Provinces has been substantial since the M.o.U was implemented in 1989. The adoption of the tridem allowed 6-axle semitrailers to emerge as an important configuration penetrating the fleet mix to a level of about 25% by 1997. Eight-axle B-trains made up about 15% of the fleet while 7-axle B-trains and A-trains all but vanished. The fleet mix distribution on the Trans-Canada Highway east corridor consists of about 60% 5-axle tractor semitrailers, 20% 6-axle tractor semitrailers, and 10% B-trains (2). There have not been significant changes in regulations in the four western provinces since 1999, so the proportion of the fleets would be expected to be maintained. The tridem drive tractor and straight truck have come into use in the forestry industry and in other heavy haul applications in British Columbia and Alberta, and these now have a small presence, displacing some tandem drive equipment and cre- ating new configurations, though their numbers are probably still quite small. Ontario began restrictions on new tri-axle semitrailers in 2001, and the first stage of gross weight reduction began in 2006 (52). The self-steer tri-axle semitrailer was introduced into regulation, but this has seen limited uptake, essentially only with an end-dump body. Semitrailers that without these restrictions would have been tri-axle vans either became tri- dem, quad or self-steer quad semitrailers. The numbers of tri- axle van semitrailers will gradually diminish through 2010. Cryogenic and other high-value tri-axle semitrailers used for transportation of compressed gas may remain in service until 2021, but any new equipment will either be a tridem, self- steer quad or M.o.U. B-train. Thus, as the proportion of the tri-axle semitrailer fleet diminishes, the proportions of the al- ternative configurations will increase. Semitrailers with more than three axles must meet Ontario’s SPIF requirements from 2006, and gross weight reductions for existing non-SPIF multi-axle semitrailers begin in 2016 (52). This has had little impact to date. It will ultimately cause a transition from about a dozen existing 4-, 5- and 6-axle semitrailer configurations to the five specified SPIF configurations. It will also greatly re- duce the number of pure Michigan configurations seen in Ontario. Michigan and Ontario carriers that operate pure Michigan configurations will either have to transition to the two 6-axle SPIF configurations provided, add liftable axles to other SPIF configurations, or accept a large reduction in gross weight for the existing Michigan configuration. Québec began its restrictions on tri-axle semitrailers in 1991, and the proportion of these semitrailers seen in the 1999 sur- vey would be expected to have diminished substantially, as they have been replaced by tridem and self-steer quad semitrailers. The four Atlantic Provinces harmonized their size and weight regulations in 2001 (37). They have also transitioned from tri-axle semitrailers to tridem semitrailers, and possibly also to some B-trains. The quad and self-steer quad semitrail- ers have also been introduced under permit, principally in New Brunswick, to accommodate trade with Québec. The propor- tion of this configuration would be expected to increase. Turn- pike Double operations are also just getting started by special permit in New Brunswick and Nova Scotia. 3.2.2 Cross-Border Fleet The 1999 National Roadside Survey also provided insight into the trucks used between Canada and the United States (65). Data were downloaded for all trips that indicated travel on roads in the United States, which provided an overview of cross-border truck traffic. However, not all data could be used for a border-crossing analysis, because it included records that did not indicate the origin, destination, or both, or indicated 28

29 the origin and destination were both in Canada, or both in the United States. This excluded about 15.72% of all cross-border trips from this analysis. A total of 154 distinct configurations were found making cross-border trips during the 1999 National Roadside Sur- vey (65). The top ten configurations accounted for 92.45% of all trips, and coincidentally included all configurations that individually contributed more than 1% of the total number of trips. Seven of the top ten configurations were specified in the M.o.U. The other three were the tri-axle semitrailer that was widely used in the six eastern provinces, the quad-axle semitrailer that was widely used in Ontario and Québec, and a 9-axle A-train that was used between Ontario and Michigan. The remain- ing 25 configurations individually contributed between 0.08 and 0.52% of the total number of trips, and collectively con- tributed 5.89% to the total number of trips. The tractor-tandem semitrailer (T12-2) was the most com- mon configuration, by a wide margin, in all provinces, and made almost two-thirds of all cross-border truck trips, a pro- portion more than 60% higher than for all trips in Canada. This effectively depressed the proportion of all other configurations. Two- and 3-axle straight trucks (S11 and S12) were the sec- ond and fifth most common configurations, and made 9.88 and 2.38% of all cross-border truck trips, respectively. These are primarily local use vehicles in both urban and rural areas. The tractor-tridem semitrailer (T12-3) and 8-axle B-train (T12-3-B2) were the third and fourth most common config- urations, respectively, and together they made 4.77 and 2.82% of all cross-border truck trips, respectively. The num- bers of B-trains crossing the borders of the four western provinces from their neighboring states is rather striking. The bobtail tandem tractor was the sixth most common configuration, responsible for 2.24% of all trips. The tractor-tri-axle semitrailer (T12-12) was the seventh most common configuration, responsible for 1.29% of all trips, from Ontario, Québec, and the four Atlantic Provinces. These vehicles can operate as a 6-axle vehicle in New York by special permit, and may also cross the border with the liftable axle raised, carrying a tandem semitrailer load. The tractor-split tandem semitrailer (T12-11) was the eighth most common configuration, responsible for 1.21% of all trips from Manitoba eastward. This is a common heavy haul vehicle in the United States that is outside the M.o.U. but continues to operate either by trip permit, by accommoda- tion in regulation, or under old regulations. The STAA double, with twin 8.53-m (28-ft) trailers (T11- 1-A11), was the ninth most common configuration, respon- sible for 0.79% of all trips. This is a U.S. configuration used for light-package freight in the U.S. A 9-axle A-train double (T12-3-A111) was the tenth most common configuration, re- sponsible for 0.61% of all trips, only between Ontario and Michigan. The four western provinces each replaced their previous reg- ulations with a set of regulations that were based directly on the M.o.U. The only significant variation was that British Colum- bia allowed 24,000 kg (52,910 lb) on any tridem spread from 2.44 to 3.70 m (96 to 146 in.), whereas the other three provinces used the loads specified in the M.o.U. These provinces all took a principled approach to vehicles entering from other juris- dictions, which were principally from or through neighbor- ing U.S. states. Vehicles that did not meet the new regulations in these provinces were denied entry. Consequently, the fleets in these provinces have not been affected by the regula- tions in the various neighboring states. These states, from Washington to North Dakota, regulate gross weight by an uncapped bridge formula, which has tended to result in long A-train configurations. The M.o.U. excludes these by length, but not necessarily by their gross weight limit of 53,500 kg (117,946 lb). However, the form of regulation has allowed these states to accommodate M.o.U. configurations, such as tri- dem semitrailers and 8-axle B-trains. Tridem semitrailers with an added liftable axle operate between British Colum- bia and Washington at a gross weight up to about 45,360 kg (100,000 lb), and B-trains operate at a gross weight up to 47,854 kg (105,500 lb). B-trains also operate on limited routes within Montana, some at their Canadian weights. 3.2.3 Unanticipated Impacts 3.2.3.1 Assessment of Dynamic Performance of Vehicles The CCMTA/RTAC Vehicle Weights and Dimensions Study developed the concept that the dynamic performance of heavy vehicles could be assessed against objective standards, and developed a process for doing this. Several provinces use the performance measures to evaluate vehicles that fall outside of the M.o.U. definitions. These vehicles typically run under special permit programs specifically designed to promote effi- cient transport. The M.o.U. configurations and allowable weights were based strictly on assessments of the performance of vehicles during the CCMTA/RTAC Vehicle Weights and Dimensions Study. How- ever, the M.o.U. addressed only tractor-semitrailers and dou- ble trailer configurations. The regulations of each province address all vehicle configurations. After the provinces had amended their regulations to implement the M.o.U., they all had essentially the same question: Now that we know the vehicles covered by the M.o.U. meet objective standards for dynamic performance, how about all the other vehicles that are allowed by our regulations? Most of these vehicles were

straight trucks and truck-trailer combinations, so a study was conducted to assess their dynamic performance, standards were drawn up, and the vehicle configurations were added to the M.o.U. (40). The same process is now used by all provinces when configurations are added to their regulations (45), (53), (54). It is also used by most provinces as part of the assessment of an application for a new configuration special permit. The outcome is that there is some uniformity in the dynamic per- formance of vehicles, and it is now unlikely that a truly poorly performing vehicle, like some that arose in the 1970s in On- tario, would get approval to operate. The staff of the provin- cial departments are now very well aware of the important parameters and can make good early judgments on whether a vehicle is likely to be feasible or not. A similar process was used in New Zealand from the early 1990s to develop weight and dimension standards and in Australia for a wide range of studies of vehicles that operate under regulations or by special permit. Australia has now gone so far as to codify a process that allows vehicles outside regulated limits to operate if they are certified to meet speci- fied performance standards by a third-party assessor (66). 3.2.3.2 Implications for Trailer Manufacturers When Ontario first began to consider adoption of the M.o.U., an immediate outcome would have been the intro- duction of 16.20-m (53-ft) semitrailers. These trailers were al- ready widely used in the United States, and U.S. carriers with these semitrailers would have gained an immediate advantage in cross-border service. Carriers with a current order for 14.65-m (48-ft) semitrailers either cancelled the order, or put it on hold pending the change so that it could be converted to 16.20-m semitrailers. Three significant manufacturers who primarily produced van trailers suddenly lost almost their en- tire order books, rapidly went into bankruptcy, and closed their plants. As the difficulty worsened, Ontario finally agreed to issue a limited number of permits to allow 16.20-m (53-ft) semitrailers and 25.0-m (82-ft) B-trains to operate while the change was made. By 1994, when it became clear that it was un- tenable to restrict 16.20-m (53-ft) semitrailers, the Ministry of Transportation announced it would change the law to allow 16.20-m (53-ft) semitrailers and 25.0-m (82-ft) B-trains, and also announced it would issue permits for new vehicles imme- diately. Manufacturers did not face a wave of cancelled orders, and many existing orders were converted from 14.65- to 16.20-m (48- to 53-ft) semitrailers. 3.2.4 Cost Recovery There has been little if any direct cost recovery from any of the changes in vehicle size and weight made in Canada. All provincial governments in Canada, and the federal govern- ment, operate under consolidated revenue, whereby virtually all income from all sources goes to the treasury, and the treas- ury disburses funds to the various operating ministries, de- partments, agencies, and others in accordance with the fund- ing budgeted annually by the provincial treasurer for the particular entity. In this process, there is no relationship be- tween the origin of any revenue and the allocation of fund- ing. So, all income derived from all aspects of trucking goes entirely into general revenue, and expenditures on highways and other aspects of highway transportation come from gen- eral revenue, but there is no requirement or expectation that income from and expenditure on these accounts should bal- ance. The same goes for any other accounts. There is one cur- rent exception to this. A carrier operating under a special per- mit through Saskatchewan’s Transportation Partnerships Program must put part of its income from the special permit operation into a fund held by the province for improvements to the roads used by the carrier under the permit (55). It has been a source of concern to some that the federal government has considerable income from fuel taxes, but spends very little on highway transportation, in part be- cause the highway networks fall under provincial jurisdic- tion. The federal government has virtually no roads under its jurisdiction but it does fund, or partially funds, various transportation related projects and programs. In general, the fuel tax portion collected by the federal government goes to general revenue for the operations and programs of the federal government. Cost recovery was not an issue for the provinces through this process, as the departments of transportation do not have the means to impose fees or taxes. Under consolidated revenue, even if additional taxes on trucking had been introduced, the provincial departments of transportation would not have had any means to capture those funds, and would have had no authority to channel them into highway programs. 3.2.5 Changes in Compliance and Enforcement When the M.o.U. was agreed upon, a tridem axle group, con- sisting of three equally spaced load sharing axles, was not legal in any of the four western provinces. Truck inspection stations in these provinces were generally fitted with a short platform scale used to weigh a single or tandem axle, by moving each axle group successively onto the scale, weighing it, and then sum- ming the axle group weights to obtain the gross weight. The tri- dem axle spread was longer than most of the platform scales, and trials quickly determined that the split-weighing of tridem axle groups did not produce a reliable result. It was therefore necessary to replace the scale at those inspection stations, where the platform was so short that it could not weigh a tridem axle group, with a spread of 3.66 m (144 in.). 30

31 The M.o.U. includes some specific dimensional limits that did not exist previously in some or all provinces. Several car- riers specified dimensions to the nearest inch of the actual metric dimension, and the manufacturers built the vehicle, either a tractor or trailer, to the specified dimension plus or minus an inch or so. This was not a problem when the error was within the legal range, but it did become a problem the other way. The first step was to measure the vehicle as accu- rately as possible. For wheelbase, axle spacings, or inter-axle spacings, this meant ensuring the vehicle was as straight as possible, measuring both sides carefully to allow for axles that set up not square to the vehicle, and then averaging the results from the two sides. When a vehicle was found that was spec- ified correctly but built out of tolerance, some provinces would issue a special permit for it at no charge, while others simply recommended that a copy of the specification be car- ried in the cab. It was recommended that carriers specify di- mensions at least 0.025 m (1 in.) on the safe side of any spec- ified dimension, to ensure vehicles would be built within the limits, including any manufacturing tolerances. In general, the M.o.U. has increased the proportion of ve- hicles in each province that are standard configurations. It has become almost unnecessary to measure vehicles that evidently conform to the M.o.U., as they can reasonably be presumed to have been built to comply with the specified dimensions. 3.3 U.S. Truck Size and Weight Regulation 3.3.1 Introduction In order to identify areas in which the Canadian truck size and weight experience might be of benefit to the United States, it is necessary to understand the U.S. truck size and weight en- vironment, and recent truck size and weight research in the United States. Truck size and weight limits were the sole jurisdiction of the states up to 1956. Since then, federal legislation has been instrumental in shaping the sizes, weights, and configurations of trucks allowed today, some nationally, and others on des- ignated and more limited networks. The Federal-Aid High- way Act of 1956 established truck size and weight limits for the Interstate system, but states with weight limits higher than the new federal limits were allowed to retain those limits under grandfather authority. Federal weight limits were in- creased in 1974 to help offset a large increase in fuel prices, but not all states adopted the higher limits. The STAA of 1982 required all states to allow twin trailers and required all states to allow weights and dimensions of certain configurations not less than specified values. The Intermodal Surface Trans- portation Efficiency Act (ISTEA) of 1991 limited the author- ity of states to increase use of double trailer combinations with a gross weight greater than 36,287 kg (80,000 lb). There have been no broad changes since 1991, though a number of specialized configurations have been defined. There have been a number of research studies addressing truck size and weight issues, and the following are briefly reviewed here: • The Turner Proposal (67), • The U.S. Department of Transportation (U.S.DOT) Com- prehensive Truck Size and Weight (CTSW) Study (68), • Review of Truck Size and Weight Limits (69), and • The Western Uniformity Scenario (70). 3.3.2 The Turner Proposal Former Federal Highway Administrator Francis Turner suggested a new approach to truck size and weight regulation in an address to the American Association of State Highway and Transportation Officials (AASHTO) in 1984. The Turner Proposal envisaged trucks with lower axle and axle group weights, on more axles than current vehicles, and with greater allowable gross weights. AASHTO asked the Transportation Research Board to establish a committee to conduct a com- prehensive study of the proposal and to advise states on its merits (67). The committee designed a package of changes in size and weight limits, safety restrictions, and procedures pertaining to bridge deficiencies, routing, and enforcement as a means of implementing the Turner proposal. The committee antic- ipated that Turner trucks, if adopted in most or all states, would reduce the cost of shipping freight and would not compromise safety. It further anticipated that the total cost of maintaining the road network would be reduced, although pavement-wear savings would be partially offset by higher bridge costs. States would incur a fiscal risk because upgrad- ing bridges would have to begin before Turner trucks could begin extensive operations, so pavement savings would lag behind the investment in bridges. During the study, the committee altered the original con- cept in two ways. First, the adoption of Turner trucks by states would be completely voluntary, and motor carriers could either continue to operate currently legal trucks or they could adopt the newer trucks. Second, the new trucks would be re- quired as a fleet to be as safe, or safer, than existing trucks and be compatible with roadway design on major roads through- out the country. The most common large truck was a 5-axle tractor- semitrailer with a maximum weight of 36,287 kg (80,000 lb) and length of 15.24 to 19.81 m (50 to 65 ft). The most com- mon multi-trailer combination had two 8.53-m (28-ft) trailers, 5 axles, a maximum weight of 36,287 kg (80,000 lb), and an overall length of about 21.34 m (70 ft). The truck

configurations considered by the study utilized a wide range of possible values for axle weights, length limits, and other vehicle characteristics in order to achieve the best perfor- mance in terms of productivity, pavement wear, bridge costs, and safety. The study considered the following prototype Turner truck configurations: • A 7-axle tractor-semitrailer with maximum weight of 41,277 kg (91,000 lb) and length of 18.29 m (60 ft); • A 9-axle A-train double trailer combination with two 10.06-m (33-ft) trailers, 51,710-kg (114,000-lb) maximum weight, and 24.69-m (81-ft) overall length; • A 9-axle B-train double with similar dimensions and weights to the preceding prototype; and • An 11-axle A-train double trailer combination with maxi- mum weight of up to 63,957 kg (141,000 lb). The Turner study evaluated the impacts of these proto- types on productivity, safety and traffic, bridges, and pave- ments. The nine-axle A-train double trailer combination was considered the most attractive to motor carriers. The adop- tion of Turner trucks nationwide was expected eventually to result in a 23% reduction of the existing combination truck miles, within 5 to 10 years after the trucks became legal. Turner trucks would attract 2% of freight ton-miles from ex- isting trucks, and 4% of rail ton-miles. Combining the larger payloads of the new vehicles with the rail diversion would yield a slight net decrease in the annual U.S. miles of combi- nation truck travel. Turner trucks were expected to offer a small decline in truck crashes and a small reduction in truck interference with traffic flow, because the total annual miles of combination-truck travel would decline. The major cost to highway agencies resulting from the Turner proposal would be bridge costs. The proposal would require replacement of 7,000 Interstate and primary highway bridges, 4% of the total, at an estimated total cost of $2.8 billion, with an additional $4.1 billion to replace bridges on the non-primary system, although some of these routes would not be critical. There would also be an additional $110 million per year needed for new bridge construction and $28 million annually once Turner truck traffic reached its long-term level. Savings in pavement wear was estimated to reach $729 million annually once Turner trucks reached long-term levels. Turner trucks would reduce the annual highway agency costs to maintain the road system by $326 million, once they reached full uti- lization nationwide. The estimates of impacts of Turner trucks were considered highly uncertain at the time of this study. Although some of the uncertainty might be less today, it still exists. Also, the re- port points out that some of the uncertainty, especially per- taining to safety, could be minimized by strict rules for oper- ating the proposed trucks. The state of knowledge of the effects of large trucks is such that the impacts cannot be fore- cast with certainty beforehand. Major recommendations pertaining to Turner trucks were made regarding: weight, dimensions, and equipment; route restrictions and driver qualifications; deficient bridges; state, federal, and industry coordination; enforcement and moni- toring; and finance. The report encouraged a national program perspective and coordination to make the Turner proposal successful, and the recommendations needed to be imple- mented as a package for the proposal to achieve its intended benefits. The study recommended the following maximum axle group weights: single axle—6,804 kg (15,000 lb), tandem axle—11,340 kg (25,000 lb), tandem drive axle—12,700 kg (28,000 lb), tridem axle—40,000 lb, and 4-axle group— 22,680 kg (50,000 lb). The study established a “bridge for- mula” but there was no “cap” or gross combination weight limit applied. Restrictions stipulated in this section related to ensuring a high level of safety were as follows: • Minimum and maximum trailer lengths, with a kingpin- to-rear-axle limit; • Antilock brakes on power units; • Minimum speed on all grades; • B-train configuration required for tank trucks; and • Newer coupling options should not be adopted until the appropriate standards could be developed. The report recommended against allowing Turner trucks on routes with substandard bridges or on routes that would otherwise not adequately serve the needs of these trucks in terms of safety or traffic operations. Each state should estab- lish a mechanism with criteria to develop a route network. The report recommended a minimum of 5 years experi- ence for drivers, with a driver training course on the specific vehicle being considered. The report encouraged states to develop a plan for replac- ing deficient bridges through development of a priority rank- ing for replacement, a timetable, a finance plan, short-term measures for mitigating bridge obstacles, postings more ac- curately based on actual capacities, and use of Turner trucks as the actual design vehicle. Coordination would be essential between state, federal, and industry components to make the Turner truck operat- ing environment viable. Turner trucks would exceed the cur- rent 36,287-kg (80,000-lb) gross weight cap applied to most of the Interstate system, except for grandfather exemptions. AASHTO would need to seek action by Congress to direct the U.S.DOT to adopt standards defining Turner trucks. States would also need to make the necessary changes to allow for Turner trucks and to determine routing and bridge posting practices. State motor carrier advisory committees and shippers 32

33 would need to provide input related to bridge postings, lim- its, and enforcement. The Turner study recommended that carriers declare their intent to operate Turner vehicles at the time of registration or when applying for a special permit. The owner should also cer- tify that vehicles and drivers comply with all restrictions that apply to Turner trucks. States should develop procedures that would help the state monitor and document factors associated with Turner truck safety. These procedures could include li- censing and certification procedures for driver qualification and training, developing report forms that identify the number of trailers and axles, and collecting travel data to be used for mon- itoring weight compliance, use, and safety of Turner trucks. Recommendations pertaining to finance included initial bridge expenditures and truck taxes. The principal financial obstacle to implementing the Turner proposal would be the cost to remove bridge deficiencies on major truck routes. The study recommended that states should seek congressional action on setting program funding levels to match the accel- erated spending for bridges in the early years after adoption of Turner trucks. This accelerated spending would be offset by reduced need for pavement maintenance in later years. Truck taxes assessed by states, toll authorities, and the federal government should reflect the differences among all vehicles. If adjustments are needed, they should provide the appropri- ate incentives to operators to choose trucks that are the most efficient, considering both highway and truck operating costs. 3.3.3 The Comprehensive Truck Size and Weight Study The U.S.DOT’s Comprehensive Truck Size and Weight Study was not primarily focused on any policy initiative, but more on development and testing of analytical tools to estimate potential diversion of traffic from one type of truck to another, or diversion between truck and rail, if truck size and weight lim- its were changed. The study also made significant improve- ments over previous studies by explicitly considering inventory and other logistics costs to shippers in making transportation decisions. Impacts of proposed size and weight changes consid- ered to be most critical were: safety, productivity, infrastructure (pavements, bridges, and geometrics), traffic congestion, envi- ronment, and railroads (68). Because safety was and continues to be a contentious issue in relation to increased truck size and weight limits, this study included an extensive review of past safety studies and devel- oped a consensus of results. The reason previous studies might still continue to raise doubts is that previous crash sta- tistics come from operating environments that are signifi- cantly different from those proposed. Therefore, this study developed tools to evaluate stability and control properties of different vehicle configurations at different weights and di- mensions. These tools were intended to provide a measure of the relative safety compared to vehicles in widespread use. The impacts of various vehicles on safety, productivity, and so forth were assessed for five truck size and weight scenarios. These scenarios were • Uniformity—Imposed federal weight limits on all non- network highways and removed grandfathered vehicles under provisions in current federal law. This resulted in a gross weight cap of 36,287 kg (80,000 lb) on all national network routes, and LCVs were impractical. • North American Trade—Increased allowable tridem axle loads to be more consistent with limits in Canada and Mexico. Tridem loads of 19,958 kg (44,000 lb) and 23,133 kg (51,000 lb) were considered. • LCVs Nationwide—Allowed LCVs on a nationwide net- work, with the largest LCVs restricted to a designated net- work, but triples combinations and doubles with 10.06-m (33-ft) trailers allowed more flexibility. • H.R. 551—Three provisions related to federal truck size and weight limits in this scenario would phase out trailers longer than 16.20 m (53 ft), would freeze state grandfather rights, and it would freeze weight limits on noninterstate portions of the National Highway System. • Triples Nationwide—Allow triple trailer combinations to operate nationwide at a gross weight up to 59,875 kg (132,000 lb), the same as in LCV nationwide scenario. Table 2 summarizes the estimates of the diversion of truck traffic for each scenario. VMT is vehicle miles of travel, in millions, and rail car-miles are also in millions. The four sce- narios allowing heavier vehicle weights all indicate large per- centage reductions in travel by 5-axle tractor-semitrailers and large increases in LCV travel. Total VMT for all scenarios is greater than current levels due to the predicted overall growth in the national economy over the study period. Impacts of the various truck size and weight scenarios on infrastructure, shipper costs, and the environment were related to the traffic diversion estimates in Table 2. Table 3 shows the estimated percentage change from the base case for key areas. The study assumed that all bridges with stress exceeding that underlying the Federal Bridge For- mula would ultimately be replaced, which is consistent with previous truck size and weight studies sponsored by U.S.DOT and TRB, though some states commented that it may overes- timate bridge-related costs. Safety impacts are not shown in Table 3 due to the difficulty in determining the impact of pro- posed changes on safety. As noted elsewhere, crash rates for vehicles with increased weight and length would need to be extrapolated from environments that are significantly differ- ent from some of those being considered. The CTSW study showed significant productivity gains for each scenario that allowed heavier vehicle weights, with the

greatest gains generated by LCVs. There were concerns that LCVs would increase infrastructure costs, adversely affect railroads, and possibly reduce safety. States differed consid- erably on changes in truck size and weight and on changes re- lated to LCVs. Many states that did not currently operate LCVs were opposed to relaxing restrictions on their use. States that allowed LCVs on state highways generally favored removing the LCV freeze and liberalizing the rules under which LCVs operate. They maintained that LCVs have demon- strated that they are safe, that LCVs improve productivity, and that current grandfather laws often result in LCVs hav- ing to operate on roadways that are not as safe as the Inter- state system. Still other states wanted to increase the gross weight for 6-axle tractor-semitrailers, and also for single-unit trucks like dump trucks, garbage trucks, and specialized haul vehicles. Such vehicles would not be expected to cause addi- tional pavement damage on Interstate highways, nor would they increase the cost of geometrics. 34 Vehicle Class 5-axle Tractor- semitrailer 6-axle Tractor- semitrailer LCVs Total Truck 2 Rail Scenario VMT % VMT % VMT % VMT % Car- miles % Base Case 83,895 6,059 1,517 128,288 25,555 Uniformity 91,205 8.7 3,519 -41.9 542 -64.3 132,351 3.2 NA3 NA3 N.A. (1) 22,274 -73.5 6,209 2.5 49,837 3185 114,671 -10.6 24,354 -4.7 N.A. (2) 24,997 -70.2 6,246 3.1 47,453 3028 114,632 -10.6 24,073 -5.8 LCVs 19,611 -76.6 NA1 NA1 40,980 2601 98,562 -23.2 20,546 -19.6 H.R. 551 83,915 0.0 6,051 -0.1 1,517 0.0 128,311 0.0 NA3 NA3 Triples 23,405 -72.1 NA1 NA1 39,647 2513 102,400 -20.2 24,533 -4.0 Note: N.A. (1)—North American Trade Scenario 1, with 19,958-kg (44,000-lb) tridem axle (90,000 lb gross N.A. (2)—North American Trade Scenario 2, with 23,133-kg (51,000-lb) tridem axle (97,000 lb gross vehicle weight). 1 Six-axle tractor-semitrailers were not included in the two scenarios involving LCVs. 2 The total does not equal the sum of the three vehicle classes shown in the table because other vehicle classes included in the total are not shown in the table. 3 Potential diversion from truck to rail under the Uniformity and H.R. 551 Scenarios could not be estimated because of lack of data on rail pricing. Source: Reference (68). vehicle weight). Table 2. Estimated diversion for selected vehicle configurations for CTSW scenarios. Uniformity N.A.Trade (1) N.A. Trade (2) LCV H.R. 551 Triples Pavement Costs -0.3 -1.6 -1.2 -0.2 0 0 Bridge Costs -13.0 +33.1 +42.2 +34.4 0 +10.4 Geometric Costs 0 +13.3 +13.3 +965.0 0 0 Congestion Costs +0.6 -1.2 -1.2 -2.9 0 -7.6 Energy Costs +2.1 -6.2 -6.3 -13.8 0 -12.8 Shipper Costs +3.0 -5.1 -7.0 -11.4 0 -8.65 Rail Contribution* N/A -42.8 -49.7 -55.8 N/A -38.2 Note: N.A. Trade (1)—19,958-kg (44,000-lb) tridem axle; N.A. Trade (2)—23,133-kg (51,000-lb) tridem axle. *The amount of rail revenue available to pay fixed costs after freight service (variable) costs have been covered. Source: Reference (68). Table 3. Estimated impacts of scenarios (percent change from base case).

35 There have been a number of state-specific exemptions to federal gross or axle weight limits authorized since 1982, in- cluding four states granted exemptions by the Transportation Equity Act for the 21st Century (TEA-21) in 1998. Increasing the semitrailer length in some states has resulted in increased cubic capacity. Since 1981, the standard semitrailer length has increased from 13.72 m (45 ft) to 14.65 m (48 ft) to 16.20 m (53 ft). Some states allow semitrailers up to 18.29-m (60-ft) long. A decrease in cargo density has actually driven the aver- age operating weight of tractor-semitrailers downward slightly in recent years. The increase in semitrailer length to 16.20 m (53 ft) has not had serious consequences, because even in the absence of a state limit on wheelbase, or the equiv- alent kingpin-to-axle dimension, most of these semitrailers operate with the bogie in a forward position to control off- tracking. Overall, however, these changes have only increased the diversity in truck size and weight nationwide. Increasing trade with Canada and Mexico will exert pressure to increase limits in the United States. The Uniformity Scenario would virtually eliminate this lack of uniformity, but there is little sentiment to roll current limits back to these levels. Cost recovery is another significant issue when consider- ing an increase in truck size and weight limits, which will undoubtedly increase the cost to maintain the infrastruc- ture. Some states capture a large share of these costs through permit fees, but other states undercharge for increases and barely cover their administrative costs. There is no means at the federal level to recover the cost of larger and heavier trucks. 3.3.4 Review of Truck Size and Weight Limits The 1998 TEA-21 directed the Secretary of Transportation to request TRB “conduct a study regarding the regulation of weights, lengths, and widths of commercial motor vehicles operating on Federal-aid highways to which Federal regula- tions apply . . . and develop recommendations regarding any revisions to law and regulations that the Board determines appropriate” (71). TRB formed the Committee for the Study of the Regulation of Weights, Lengths, and Widths of Com- mercial Motor Vehicles to conduct the work (69). The major conclusions of this study were as follows: • Opportunities exist for improving the efficiency of the highway system through reform of federal truck size and weight regulations, which reform may involve allowing larger trucks to operate. • Federal truck size and weight regulations should facilitate safe and efficient freight transportation and interstate commerce, establish highway design parameters, and help manage consumption of public infrastructure assets. • Changes in truck size and weight regulations, in coordina- tion with complementary changes in the management of the highway system, offer the greatest potential to improve the functioning of the system. • The methods used in past studies have not produced satis- factory estimates of the effect of changes in truck weights on bridge costs. • It is not possible to predict the outcomes of regulatory changes with a high degree of confidence. • It is important to examine the safety consequences of size and weight regulation. Research is needed to understand the relationship of truck characteristics and truck regula- tions to safety and other highway costs. • Violations of size and weight regulations are considered an expensive problem, but monitoring of compliance with the regulations is too unsystematic to allow the costs involved to be estimated. The major recommendations of this study were as follows: Congress should create an independent public organi- zation charged with observing and evaluating commercial motor vehicle performance and the effects of size and weight regulation, which the committee called the Commercial Traf- fic Effects Institute. The Institute could enter into agreements with private sector entities to conduct joint programs of data collection and research. The legislation creating the Institute should define the scope of its activities by specifying three distinct functions: • The conduct of pilot studies of proposed new vehicles and related operating principles; • Monitoring and ongoing program evaluation to measure whether practices intended to control safety and operations were functioning as intended; and • Support for state implementation of federal size and weight regulations. Congress should authorize the Secretary of Transportation to approve pilot studies of temporary exemptions from fed- eral size and weight regulations. A pilot study is defined as a controlled experiment designed to measure the effects of changes in truck size, weights, or operating practices. Federal law should allow any state to participate in a feder- ally supervised permit program for the operation of vehicles heavier than the present federal gross weight limit, provided the state meets the requirements of the program. The Com- mercial Traffic Effects Institute should monitor the conse- quences of the federally supervised permit program, but the overall federal role in defining numerical dimensional lim- its would be diminished. Instead, the federal government would have greater involvement in ensuring that state reg- ulations pertaining to vehicles on federal-aid highways were

contributing to national objectives. States would be allowed to issue permits for 6-axle tractor-semitrailers with maxi- mum weight of 40,823 kg (90,000 lb), and double trailer com- binations with each trailer up to 10.06 m (33 ft) in length with seven, eight, or nine axles, and weights governed by the pres- ent Federal Bridge Formula. The definition of vehicles eligi- ble for permitting would be subject to revision over time, but federal review of the performance of the permitting program would be permanent and ongoing. The federal government would require states to provide suitable and specified levels of enforcement, user fees, safety, and bridge management. Enforcement requirements might require states to effectively hold accountable the parties re- sponsible for placing overweight loads on the highways and to target repeat offenders. Examples might be “relevant evi- dence” statutes and information systems to facilitate identi- fying offenders. User fees should be structured to cover both the administrative and infrastructure costs associated with the program. Safety requirements should be proposed by states, reviewed by the Commercial Traffic Effects Institute, and approved by the Secretary. Bridge management requires that each state develop a plan for cost-effectively alleviating the constraints on permit vehicles due to deficient bridges. Federal law should allow operation of LCVs under the pro- visions of the federally supervised permit program in a man- ner consistent with other recommendations. The committee did not recommend general revision in the network of roads to which the various federal dimensional regulations are applicable. In particular, the committee did not recommend extending federal weight regulation to the non-interstate portion of the National Highway network, which are currently under state regulation for most aspects of truck operations. The preceding recommendations call for data collection for systematic monitoring of truck traffic and truck costs to eval- uate regulatory effectiveness, pilot studies to test new vehicles, and basic research on the relationship of truck characteristics to highway costs. Specific research topics were: • Evaluation of the effectiveness of enforcement of size/ weight regulations, • Air quality impacts of changes in truck characteristics, • Relation of truck performance to crash involvement, • Risk-based bridge costs, • Freight transportation market research, • Costs of mixed automobile and truck traffic arising from nuisance/stress, and • New infrastructure development and truck-only facilities. 3.3.5 The Western Uniformity Scenario Following the CTSW study, the Western Governors’ Asso- ciation requested that U.S.DOT analyze an additional sce- nario that would be limited to western states already allowing LCVs. Specifically, the governors asked U.S.DOT to analyze a policy option that would allow 13 western states (Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, North Dakota, Oklahoma, Oregon, South Dakota, Utah, Washington and Wyoming) to harmonize LCV weights and dimensions at lev- els that meet existing federal axle load limits and the Federal Bridge Formula and that were consistent with guidelines es- tablished by the Western Association of State Highway and Transportation Officials (WASHTO). The ten impact areas were the same as those used in the CTSW study. These states contain a higher percent of rural roads than urban roads as compared to the nation as a whole (70). The Western Uniformity Scenario analysis included sev- eral substantial improvements to data and methods used in the CTSW study to estimate scenario impacts. These included improvements in the truck and rail data, and methods used to analyze pavement, bridge, and safety impacts. One of the biggest improvements was the use of the freight analysis frame- work (FAF) commodity-flow data in place of the very limited truck-flow data that was available at the time the CTSW study was undertaken. The analysis includes the following vehicles: 5-axle tractor- semitrailers, twin 8.69-m (28.5-ft) trailers, and five LCVs, in- cluding Rocky Mountain doubles, turnpike doubles, triples, a 10-axle resource-hauling double, and 8-axle B-trains. The base case for the analysis was: • 9,071 kg (20,000 lb) for a single axle on the Interstate system, • 15,422 kg (34,000 lb) for a tandem axle on the Interstate system, • Application of the Bridge Formula for other axle groups, up to the maximum of 36,287 kg (80,000 lb) for gross vehicle weight on the interstate system, • 2.59-m (102-in.) vehicle width on the national network, • 14.65 m (48 ft) minimum semitrailer length in a semitrailer combination on the National Network, and 8.53-m (28-ft) minimum length for trailers in a twin-trailer combination on the national network, • Grandfather rights under which certain LCVs are allowed to operate in each scenario state, and • LCVs that were permitted by state law but subject to the LCV freeze. The conclusions of the Western Uniformity Scenario analy- sis were similar in some ways to previous study findings. First, the proposed scenario vehicles and routes varied significantly, but basically allowed more generous gross weight and addi- tional routes compared to the base case. Like previous studies that examined the potential impacts of changing truck size and weight limits, this study found several benefits from al- lowing more widespread use of LCVs. The benefits included 36

37 a reduction in fuel consumption, emissions, and noise-related costs. However, the full benefits estimated in this study would probably not be realized because not all states would allow LCVs to operate as widely as assumed in the study. One dif- ference with this study compared to previous studies is that infrastructure and related costs should not be as great because LCVs already operate on at least some highways in each of the 13 states. So, to a certain extent, states have already consid- ered LCV size and weight in pavement, bridge, and geomet- ric design. The study found that few of the states charge enough for LCV operations to cover the infrastructure costs, and when heavy trucks do not pay their share, other motorists must make up the difference. The study recommended that plans should be developed for financing those improvements that include how the longer, heavier trucks would contribute to paying those costs before making changes in truck size and weight limits that could increase highway improvement needs. The report cited a conclusion from TRB Special Report 267, “federal legislation creating the permit program should specify a quantitative test for the revenue adequacy of the per- mit fees imposed by states that wish to participate. . . . Fees should at least cover estimated administrative and infrastruc- ture costs for the program . . .” (69). On the critical topic of safety, this report concluded that the available data are simply not sufficient for developing reliable estimates of changes in the number of crashes or fatalities that might result from the proposed changes. States that currently allow LCV operation have not noted particular safety prob- lems with LCVs, but they have no formal processes in place to monitor safety. Therefore, one suggestion in the conclusions was to require such processes before any substantial changes in federal truck size and weight limits were implemented. An- other suggestion was to consider requirements to ensure that proposed vehicles meet some minimum thresholds for stabil- ity and control, and that companies operating these vehicles have good safety records and vehicle maintenance programs. The Western Uniformity Scenario conclusions also point out some of the salient points of harmonization, which was a central theme of the study. Some of its points favor harmo- nization but others appear to justify a more neutral position. For example, in a statement that seems to justify the status quo, it states that the pattern of truck size and weight limits that has evolved over the years among states involved in the study may not be optimal, but it allows for some appropriate regional variation without compromising safety. Somewhat to the contrary, it refers to recent state-specific exemptions from federal truck size and weight laws that have been enacted, stating that the U.S.DOT does not support a piecemeal ap- proach. Reasons not to support this approach include: it makes enforcement and compliance with truck size and weight laws more complicated, it may have unintended consequences for safety and highway infrastructure, it often contributes little to overall productivity, and it reduces willingness to work for more comprehensive solutions that could have greater bene- fits. A regional approach such as the Western Uniformity Sce- nario could have greater benefits than a series of individual exemptions, but it also could have much more serious ad- verse consequences unless closely monitored. It also contended that strong support for the TRB recom- mendations in Special Report 267: Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles (69) has not been evident, except for certain segments of the trucking industry and several states that are interested in size and weight increases. The Department has not taken a formal po- sition on the TRB study, partly because it does not favor change in federal truck size and weight policy. However, if changes should occur, the U.S.DOT favors strong monitor- ing and evaluation as recommended by the TRB study. Finally, the conclusions emphasize that strong support from elected state officials within the region is essential and critical for successful change in truck size and weight limits. Without such support, it will be difficult to achieve a carefully controlled and monitored evaluation of changes in truck size and weight limits such as those in the Western Uniformity Scenario. Such state support has not been evident to date, and there is no compelling federal interest in promoting changes that are not strongly supported by the affected states. 3.3.6 Research Recommendations and Results This section looks at the recommendations of each of the four studies just discussed, and provides information on re- sults of major recommendations. 3.3.6.1 The Turner Proposal The Turner proposal recommended lower axle group weights and more axles so that a higher gross weight is achieved, which would require the 36,287 kg (80,000 lb) to be removed (67). Industry did not believe there was enough payload gain to justify the expense of different equipment, so this major recommendation of the study was not imple- mented. Most of the other recommendations were contingent upon adoption of Turner truck. The recommendation for an- tilock brakes on power units has happened, but due to other federal safety requirements, none of the other safety recom- mendations were adopted. 3.3.6.2 The CTSW Study The primary goal of the CTSW study was the development and testing of analytical tools to estimate potential diversion

of traffic from one type of truck to another, or diversion be- tween truck and rail, if truck size and weight limits were changed. Even though this study included an extensive review of past safety studies and developed a consensus of results, there was still a lack of confidence in these results. The use of crash statistics from operating environments that are signifi- cantly different from those proposed was a major source of this doubt. This study developed tools to evaluate stability and control properties of different vehicle configurations at different weights and dimensions. These tools were intended to provide a measure of the relative safety compared to vehi- cles in widespread use. Since the major emphasis of the CTSW study was the development of analysis tools, it did not make strong recommendations for change related to truck size and weight (68). 3.3.6.3 Regulation of Weights, Lengths, and Widths of Commercial Motor Vehicles The recommendation to form a Commercial Traffic Ef- fects Institute would have, in a general sense, followed the Canadian example in creating a less political, or nonpolitical entity, for addressing, in a highly technical manner, issues with truck size and weight. This was not acted upon, so other recommendations contingent on formation of the Institute did not happen. It is unclear whether this study was the impetus of some of the research that has ensued, but some of the topics identified in the study have been topics of ongoing research (69). 3.3.6.4 The Western Uniformity Scenario The Western Uniformity Scenario emphasized findings and conclusions more than recommendations. It advocated developing plans for financing those improvements to infra- structure, including how the new trucks that are responsi- ble for additional costs would contribute to paying those costs (70). The Western Uniformity Scenario noted that a recommen- dation in the TRB review of truck size and weight limits would essentially result in conducting experiments with ve- hicles that were known not to be safe. This study advocates, to the maximum extent possible, giving assurances that the vehicles to be used would be at least as safe as vehicles on the road today and that the companies to be operating those ve- hicles would have excellent safety records. The Western Uniformity Scenario advocated a regional ap- proach to truck size and weight change, which could have greater benefits than a series of individual exemptions, but it also could have much more serious adverse consequences un- less closely monitored. Also, such an approach for a carefully controlled and monitored evaluation of changes in truck size and weight limits must have strong support from elected state officials. These positions presented in the Western Uniformity Sce- nario have not found fulfillment to date. Regional application of size and weight issues is already being done successfully through AASHTO subgroups, al- though it can have negative consequences such as heavier trucks on roads that may not be the safest. Regional permit- ting is discussed in more detail elsewhere. 3.3.7 National Legislative Actions By the end of the 1970s, there was something of a patchwork of state truck size and weight limits. Not all states allowed dou- bles, and overall length limits in others either restricted semi- trailer length or effectively limited doubles. Some states still re- tained the 33,240-kg (73,280-lb) gross weight, and axle weights lower than current federal limits. The 1982 STAA required states to allow larger trucks on the national network, which is comprised of the Interstate system plus the non-Interstate federal-aid primary system. “Larger trucks” included • Doubles with a trailer length not less than 8.53 m (28 ft); • A semitrailer not less than 14.65-m (48-ft) long; • Unlimited length for tractor-semitrailer and double trailer combinations; • Width up to 2.59 m (102 in.); • A single axle weight not less than 9,072 kg (20,000 lb), a tandem axle weight not less than 15,422 kg (34,000 lb), and a gross weight determined by Bridge Formula B, up to 36,287 kg (80,000 lb), as is shown in Figure 24 (71). The current truck weight limits for most major U.S. high- ways are based on Bridge Formula B: where W = the maximum allowable weight (lb) on the N axle group being considered and L = the extreme axle spacing (ft) of this group. Additionally, a maximum gross vehicle weight of 80,000 lb applies, with a 20,000-lb limit on a single axle and a 34,000-lb limit on a tandem axle with a spread of 4 ft (71). This formula was recommended in the 1964 House Docu- ment 354 and was adopted in 1975. The reported basis for this formula was an allowable overstress of 5% in bridges de- signed for HS20 loadings and 30% in bridges designed for H15 loadings. A footnote in the House Document also incor- porated in the resulting legislation prohibited certain vehi- cles, otherwise legal according to Bridge Formula B, from operating on H15 bridges, but these prohibitions are not often enforced. W LN N N= − + + ⎛⎝⎜ ⎞⎠⎟500 1 12 36 38

39 The STAA set minimum limits, and most states chose not to exceed them, bringing a significant measure of unifor- mity to the truck traffic on the National Network. It did nothing for other vehicles that operated on state roads under state legislation, and states increasingly exploited their grandfather rights to allow more and different vehicles on more roads. The ISTEA of 1991 therefore imposed two separate freezes: • On the maximum weight of LCVs, which consist of any combination of a truck tractor and two or more trailers or semitrailers operating on the Interstate system at a gross weight over 36,287 kg (80,000 lb). • On the overall length of the cargo carrying units of com- bination vehicles with two or more such units where one or both exceed 8.69 m (28.5 ft) in length on the national network. The LCV freezes applied to combination vehicles in actual and legal operation in a state on June 1, 1991, and the routes and conditions in effect on that date were also frozen for ve- hicle combinations subject to the freeze (73). National policy on truck size and weight has not changed significantly since the 1991 ISTEA, except that a small number of specialized vehicle configurations have been added to the regulation, and details for some of these have been amended. (a) The provisions of the section are applicable to the National System of Interstate and Defense Highways and reasonable access thereto. (b) The maximum gross vehicle weight shall be 80,000 pounds except where lower gross vehicle weight is dictated by the bridge formula. (c) The maximum gross weight upon any one axle, including any one axle of a group of axles, or a vehicle is 20,000 pounds. (d) The maximum gross weight on tandem axles is 34,000 pounds. (e) No vehicle or combination of vehicles shall be moved or operated on any Interstate highway when the gross weight on two or more consecutive axles exceeds the limitations prescribed by the following formula, referred to as the Bridge Gross Weight Formula: except that two consecutive sets of tandem axles may carry a gross load of 34,000 pounds each if the overall distance between the first and last axle is 36 feet or more. In no case shall the total gross weight of a vehicle exceed 80,000 pounds. (f) Except as provided herein, States may not enforce on the Interstate System vehicle weight limits of less than 20,000 pounds on a single axle, 34,000 pounds on a tandem axle, or the weights derived from the Bridge Formula, up to a maximum of 80,000 pounds, including all enforcement tolerances. States may not limit tire loads to less than 500 pounds per inch of tire or tread width, except that such limits may not be applied to tires on the steering axle. States may not limit steering axle weights to less than 20,000 pounds or the axle rating established by the manufacturer, whichever is lower. (g) The weights in paragraphs (b), (c), (d), and (e) of this section shall be inclusive of all tolerances, enforcement or otherwise, with the exception of a scale allowance factor when using portable scales (wheel-load weighers). The current accuracy of such scales is generally within 2 or 3 percent of actual weight, but in no case shall an allowance in excess of 5 percent be applied. Penalty or fine schedules which impose no fine up to a specified threshold, i.e. , 1,000 pounds, will be considered as tolerance provisions not authorized by 23 U.S.C. 127. (h) States may issue special permits without regard to the axle, gross, or Federal Bridge Formula requirements for nondivisible vehicles or loads. (i) The provisions of paragraphs (b), (c), and (d) of this section shall not apply to single-, or tandem-axle weights, or gross weights legally authorized under State law on July 1, 1956. The group of axles requirement established in this section shall not apply to vehicles legally grandfathered under State groups of axles tables or formulas on January 4, 1975. Grandfathered weight limits are vested on the date specified by Congress and remain available to a State even if it chooses to adopt a lower weight limit for a time. Figure 24. Excerpts of code of federal regulations part 658. Source: Reference (71).

40 3.3.8 State Legislative Actions Limits on truck size and weight appear in state regulations as early as 1913, when weight limits were introduced in Maine, Massachusetts, and Washington, and weight and width limits were introduced in Pennsylvania. The last state to enact a weight limit was North Dakota, in 1933. States were slower to adopt limits on length, width, and height than they were on weight, but by 1929, most states restricted these di- mensions as well as weight (74). Size and weight limits have generally increased over time to allow for larger and heavier vehicles and have varied significantly from state to state, and have changed frequently. A 1941 federal study documented 300 changes in individual state size and weight laws between 1913 and 1941, or about one change every 4 years per state (75). State to state variation in some limits has narrowed over time, but uniformity of combination truck length limits has not improved. The recommended policies of AASHTO have been a model for many states since the first policy was adopted in 1931, when AASHTO urged states to adopt uni- form regulations to promote efficiency and safety and to allow for standardized highway design. Even though some states have used AASHTO policies, their appeal for unifor- mity has had limited effect (74). A shift of some truck size and weight regulatory authority from the states to the federal government occurred at the start of the Interstate construction era in the 1950s, and since then, the distribution of this shared authority has shifted back and forth. As the Interstate construction era draws to a close, the transportation community is again reassessing the federal role in the context of future highway transportation needs. The federal size and weight rules in the 1982 STAA super- seded many state limits, at least as they applied to the desig- nated network where trucks meeting the federal standards may operate. Primary elements of these rules included the operation of twin trailer combinations, 14.65-m (48-ft) semi- trailers, and vehicle width of 2.59 m (102 in.). At the end of 1982, 36 states allowed 19.81-m (65-ft) long twin trailer com- binations on at least some roads. Several states required spe- cial permits for their operation, and 14 states restricted the operation of twins to designated highways. Semitrailers 14.65-m (48-ft) long were legal on some roads in 35 states in 1982, and 10 states allowed 2.59-m (102-in.) wide trucks. The federal requirement that no overall length limit be imposed for the affected combination vehicles overturned such limits in all 50 states (74). The 1982 STAA mandated a nationwide network of routes for the operation of 8.53-m (28-ft) double trailers and 14.65-m (48-ft) semitrailers. Some states have been reluctant to push the size and weight issue even to federal maximums in all cases, while other states have sought increases beyond fed- eral maximums—even if on less safe roads. These differences will continue to force a piecemeal approach to size and weight and will force many bigger and heavier trucks onto roadways not designed for their use. Another variable among states is the use of permits. Many states allow exemptions for certain classes of vehicle, or com- modities, either with or without permits. Many northeastern states allow higher weight limits through a special truck regis- tration or permit. Other states issue permits for divisible loads under grandfather authority. In 1985, 37 states issued 153,642 divisible load permits, and in 1995, this same number of states issued 380,511 permits. The number of permits issued for spe- cific commodities continues to increase as well. For example, in 1995, Pennsylvania added two new overweight permits for 42,638 kg (94,000 lb) gross weight and 9,525 kg (21,000 lb) per axle on state highways, but only for steel coils and milk. In 1996, the Pennsylvania legislature added bulk animal feed (68). Such exemptions and exceptions are pervasive through- out the United States and seem to continue as time goes on. 3.3.9 Regional Initiatives AASHTO is interested in investigating size and weight is- sues. The major goal of AASHTO efforts to date has been har- monization among states in a given region. AASHTO devel- oped a position at its 2007 meeting pertaining to regional harmonization, encouraging states to harmonize on a regional basis. An example of this regional cooperative arrangement is the WASHTO, which consists of the following states: Ari- zona, Idaho, Montana, Oregon, Utah, Washington, Texas, New Mexico, Colorado, Oklahoma, Nevada, Alaska, California, Hawaii, North Dakota, South Dakota, and Wyoming. One of the options under this arrangement is a multistate single-trip permit issued under the Western Regional Permitting Agree- ment. Under the terms of the agreement, each member state may issue regional permits allowing operation in any other member state (76). Both WASHTO and the Southern Associ- ation of State Highway and Transportation Officials (SASHTO) have done a considerable amount of (divisible load) permit- ting as well. Neither the Mississippi Valley nor Northeastern Association of State Highway and Transportation Officials (NASHTO) have been as active as other regions in promoting regional divisible load permitting, according to an AASHTO spokesman. All interested states must agree to harmonization to get something meaningful started, and to make the efforts an ongoing success. In a May 2000 workshop involving stakeholders following the U.S.DOT CTSW study, participants spoke favorably re- garding regionalism and trade corridors (77). The majority of participants favored more state flexibility for regional poli- cies, and a special permit system with strong enforcement was generally viewed as a must for regional truck size and weight limits. Multi-state agreements are recognized as a means of

promoting and implementing regional truck size and weight policies. Participants recognized, however, that to avoid states having total control over truck size and weight limits, a federal umbrella would be needed to impose some overall limits on flexibility. 3.3.10 The Corridor Perspective The American Road and Transportation Builders Associa- tion (ARTBA) recently articulated a vision for the future to be included in the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA- LU) legislation. The heart of that vision was a new, more ac- countable, structure for the federal highway program consist- ing of two components, one to preserve and improve the current highway and transit systems through a significant in- crease in federal user fees and the second, and more critical to this topic, the creation of an integrated, national strategy that ARTBA refers to as “Critical Commerce Corridors.” The pro- gram, sometimes referred to as the “3C Proposal,” would facilitate the safe and efficient movement of freight and re- duce the impact of truck traffic (78). This ARTBA vision was borne, at least partly, out of a sense of global competition. China has a massive strategic trans- portation plan underway to build 68,000 km (42,000 mi) of new interstate highways in 20 years, India is building 40,000 km (25,000 mi) of expressways, and the European Union is adding nearly 16,000 km (10,000 mi) of new highway and rail capacity. The ARTBA initiative stresses that the United States is in a global economy and must also establish a competitive plan to meet future transportation needs. The Critical Commerce Corridors Proposal is intended to address America’s freight challenges and handle the expected doubling of truck traffic over the next 25 years. The 3C pro- gram would provide new surface transportation system capac- ity and operational improvements focused on safe and effi- cient movement of freight. A secondary use of these corridors might be for evacuation purposes in times of national emer- gencies or disasters. Financing of the program could come from dedicated and protected user fees levied on freight shipments and could involve public-private partnerships and debt financing. The U.S.DOT would lead this effort in collaboration with public and private sector stakeholders. This cooperative public- private sector process would develop the costs and specific components of the program. Components of this program as envisioned by ARTBA are: • Most, if not all, of the existing Interstate highway system and a portion of the non-Interstate national highway system; • New multimodal trade corridors; • New “truck only” lanes allowing increased productivity and improved safety through separation of commercial ve- hicles from personal vehicles; • “Last mile” military base, port, airport, inland waterway and rail connections; • Tunneled and elevated roads and railways on existing right-of-way; • International gateways; • Bottleneck relief; • Multimodal freight transfer centers; and • Integrated telecommunications corridors. The issue of trade corridors was also discussed at length at the stakeholder workshop noted above (77). These partici- pants believe that, under carefully controlled conditions, such corridors could be candidate sites for operations of larger ve- hicles at higher weights. Some expressed concerns, however, about cost and the potential for off-corridor operations, such as trucks not staying in specified lanes or corridors. On high volume freight corridors there may be opportunities for sep- arate truck lanes. Some workshop participants felt that con- sideration should be given to liberalizing federal truck size and weight limits for some trade corridors. Due to uncertain- ties concerning potential impacts of liberalizing size and weight limits, there was a consensus that any initiative would probably have to be in the form of a demonstration project with a well defined termination date and strong controls so that the project could be ended if necessary (77). 3.3.11 The Bridge Perspective 3.3.11.1 Design Loadings The H and HS truck live-load model was adopted in 1944, and since then, variations of this basic model (H15-44, H20-44, HS15-44, HS20-44) have been the basis of the live load model used by designers of almost all bridges in the United States. The “-44” indicates the series by year of adop- tion, 1944. The HS model consists of a two-axle truck plus a semitrailer with a variable trailer wheelbase of 4.27 to 9.14 m (14 to 30 ft). The total weight on the first two axles of the H and HS trucks is designated (in tons) by the numeral follow- ing the H or HS designator, with 20% on steering axle and 80% on the drive axle, with the weight on the third (trailer) axle identical to that on the tractor drive axle. The gross vehi- cle weight of an HS20-44 then is 32,658 kg (72,000 lb), or 36 tons, with 20 tons on the tractor and a 16 ton trailer axle. The HS20 live-load model also includes a uniformly distrib- uted lane loading of 952 kg/m (640 lb/ft) plus a concentrated load of 8.164 kg (18,000 lb) when checking moment, or 11,793 kg (26,000 lb) when checking shear. The live-load model uses the truck or lane loading that creates the maximum 41

value of the load effect being checked. For example, when checking moments in a simple span bridge, the truck governs for spans of 140 ft and shorter, while the lane load governs for longer spans. Most on-system bridges designed today in the United States are designed for HS-20 loading. Canadian bridges are designed for one of two live load models, the Ontario Bridge Design Code (OBDC) within On- tario or the CSA in other Canadian provinces. The OBDC uses the Ontario Highway Bridge Design (OHBD) live-load model, which is a 5-axle vehicle currently of gross vehicle weight 740 Kn (166,400 lb). This vehicle has evolved and has been calibrated to surveys of actual truck traffic, particularly maximum observed overloads. Figure 25 compares the sim- ple span moments caused by the then current OHBD design vehicle with the HS20-44 design vehicle (79). The current OHBD design vehicle is heavier after a recent recalibration against current truck weight surveys. Figures 26 and 27 report the ratio of the simple span moments of the OHBD design vehicle and the HS20 design vehicle. The dif- ference, due to the most recent changes in the OHBD vehicle, is most noticeable in short span bridges (10 to 20 m), whereas the ratio to HS20 moments has increased significantly with the recalibration. Bridge design in other Canadian provinces follows the CAN/CSA-S6-06 Code. The design vehicle in this Code is cur- rently the CL-625 5-axle vehicle with a gross weight of 625 Kn (140,456 lb) and an 18-m (59-ft) wheelbase. There are minor differences in the application of the design vehicle between the CSA and OHBD codes, specifically in the way superimposed lane loadings are handled, in the way impact or dynamic load allowances are handled, and in the load factors used in load factor design (LFD). The end result is that the two Canadian design codes result in very similar design moments on sim- ple span bridges of a given span length, and the moments re- sulting from these two design codes are significantly greater than those resulting from the AASHTO LFD design process that uses the HS20 design vehicle. With the exception of short span bridges, with a span up to 15 m (49 ft), designed for CL-625 loadings, Canadian bridges are designed for sig- nificantly greater loadings than U.S. bridges designed for HS20 loadings. The OHBD design vehicle is based on maximum observed overloads, and is multiplied by a live-load factor of 1.40, whereas the CAN/CSA-S6 design vehicle is based on regula- tory loadings and is multiplied by a live-load factor of 1.60. The HS20 loads are multiplied by a live-load factor of 1.67 in the AASHTO LFD design procedure. It is observed in Figure 28 that the design loadings for HS20, OHBD, and CL-625 are also different in the way in 42 Figure 25. Comparison of simple span moments of Canadian design vehicle versus HS20. 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 0 10 20 30 40 50 60 Span (m) M om en t R at io No Impact With Impact Figure 26. Ratio of unfactored design moments by current OHBD and HS20 design vehicles on simple spans, with and without impact.

which truck loads and lane loads are combined. In the case of AASHTO design with HS20 vehicles, truck loads are used alone until lane loads with a single concentrated 8,164 kg (18,000 lb) axle load take precedent. For simple spans, this means that truck loads govern for spans shorter than 42.67 m (140 ft), and lane loads govern for spans longer than this. Both the OHBD and CL-625 design vehicles are combined with lane loadings (the loading may be governed by an unfac- tored truck or a reduced truck combined with a lane loading). For the OHBD, the combined truck/lane loading begins to govern at about 35 m (115 ft), and the CL-625 combined loading governs at even shorter spans. (See Figure 28.) 3.3.11.2 Bridge Population in the United States The National Bridge Inventory documents the bridge pop- ulation of the United States (80). Data from that inventory are summarized in Figure 29, which breaks down the approx- imately 597,000 bridges by year of construction. This shows that few bridges were constructed during World Wars I and II, and much of the current inventory dates from the 1960s, when most of the Interstate highway system was under con- struction. Figure 29 also shows the bridges classified as struc- turally deficient as of May 2006. Table 4 shows a summary of the design loadings used for design of the nation’s 682,482 bridges in the National Bridge In- ventory as of 2006 (80). Nationwide, about 14% of the nation’s existing bridges were designed for HS15 or lighter loadings, with another 18% having “other or unknown” design load- ings. Of all currently existing bridges in the nation, 45% are designed for HS20 or a modified HS20 loading. However, only 3.30% are known to be designed for HS25 or heavier loadings. Most bridges built in the United States today are designed for HS20 loadings, but this is not true for all bridges in the ex- isting bridge inventory. As an indication, consider the follow- ing statistics for the inventory of 49,593 bridges in Texas from the National Bridge Inventory data files (80). Seventy-four percent of the 10,237 bridges built in Texas in 1990–2006 were 43 Ratio of Factored Moments 0.0 0.5 1.0 1.5 2.0 0 10 20 30 40 50 60 70 Simple Span (m) M om en t R at io OHBD/HS20 CL-625/HS20 Figure 27. Comparison of factored design moments by Canadian design Loads on simple spans to HS20 factored design moments, with impact. 0 5000 10000 15000 20000 25000 Fa ct or ed (L L+ I) M om en t ( kN -m ) OHBD*1.4 CL-625*1.6 HS25*1.67 HS20*1.67 0 10 20 30 40 50 60 70 Simple Span (m) Figure 28. Factored design moments by current Canadian and HS20 design vehicles on simple spans, with impact.

designed for HS20 loadings. The design load is indicated as “other or unknown” in the database for most of the remain- ing bridges (23%), though essentially all highway bridges in Texas were probably designed for HS20 loadings during this period. However, before 1960, 34% of the existing 16,527 bridges built in Texas at the time were designed for H15 load- ings. And, in the 1960s, during the Interstate highway con- struction boom, 9,327 existing bridges were built in Texas with about 11% designed for H15 loadings. Consequently, in 2006, about 15% of the state bridge inventory presently in use was originally designed for a loading less than HS20. 3.4 Application of Canadian Experience to the United States This section summarizes elements of the Canadian experi- ence, both the impacts of the size and weight limits and the process used to harmonize them, which may have relevance for U.S. regulators. It identifies areas in which the Canadian truck size and weight limits have resulted in particular suc- cesses, or problems. 3.4.1 Freight and Trucks In Canada, low-density freight moves in 5-axle tractor- semitrailers below mass capacity, however, when loads of higher density freight are traveling to or from the United States in 5-axle tractor-semitrailers, they tend to be loaded close to the maximum permissible weight of 36,287 kg (80,000 lb). The allowable gross weight of this vehicle is 39,500 kg (87,082 lb) in the four western provinces, and 41,500 kg (91,491 lb) in the six eastern provinces. Generally, if a commodity would chal- lenge the weight capacity of a 5-axle tractor-semitrailer, then more of it can be carried in a vehicle with greater weight ca- pacity, so that is how it moves. The 6-axle tractor-semitrailer, with a tridem semitrailer, has an allowable gross weight from 44 10000 20 02 -2 00 6 19 97 -2 00 1 19 92 -1 99 6 19 87 -1 99 1 19 82 -1 98 6 19 77 -1 98 1 19 72 -1 97 6 19 67 -1 97 1 19 62 -1 96 6 19 57 -1 96 1 19 52 -1 95 6 19 47 -1 95 1 19 42 -1 94 6 19 37 -1 94 1 19 32 -1 93 6 19 27 -1 93 1 19 17 -1 92 1 19 22 -1 92 6 19 12 -1 91 6 19 06 -1 91 1 19 05 a nd e ar lie r 0 20000 30000 40000 N um be r o f B rid ge s Bu ilt 50000 60000 All Bridges Structurally Deficient Bridges Figure 29. Year of construction of U.S. bridges as of 2006. Design Load Count of Bridges Fraction Other, or unknown 120,497 17.66% H10 11,389 1.67% H15 70,244 10.29% HS15 11,997 1.76% H20 53,977 7.91% HS20 229,486 33.63% HS20+Mod 64,210 9.41% Pedestrian 534 0.08% Railroad 253 0.04% HS25 22,514 3.30% Table 4. National Bridge Inventory system bridge-design loads as of 2006.

43,500 to 49,500 kg (95,900 to 109,127 lb), depending on the tridem spread and whether it operates in western or eastern Canada, and 6-axle A- or B-train doubles are suitable for freight of moderate density. The 7-axle B-train, with an allow- able gross weight of 56,500 kg (124,560 lb) in the four western provinces, and 59,500 kg (131,173 lb) in the six eastern provinces, and the self-steer quad 7-axle tractor-semitrailer, with an allowable gross weight of 57,500 kg (126,764 lb) in Ontario and Québec, are suitable for higher density freight. Seven-axle doubles are not common, but the self-steer quad is very significant because it has had greater range in Québec than the 8-axle B-train. The 8-axle B-train, 8- and 9-axle tractor-semitrailers, and other doubles in Ontario, all with an allowable gross weight from 62,500 to 63,500 kg (137,787 to 139,992 lb), move dense and heavy freight. The truck size and weight regulations in Canada therefore provide a range of pay- load weight bands that allow shippers and carriers to optimize a truck configuration for a payload. In the United States, the same light freight moves in 5-axle tractor-semitrailers as in Canada, at the same gross weights. The 5-axle tractor-semitrailer also moves medium and heavy freight, both locally and between states, usually at a gross weight close to 36,287 kg (80,000 lb). Medium and heavy freight also moves locally in diverse other configurations that operate under grandfather or LCV rights, principally within one state, or pos- sibly by permit into neighboring states. Michigan is really the only state that has a range of configurations that address a range of freight like Canada, though most of these would not be con- templated as candidates for the M.o.U. in Canada. In Canada, about 60% of trips are made by trucks that carry light freight, such as the 5-axle tractor-semitrailer with a typical actual gross weight up to 36,287 kg (80,000 lb). About 13% of trips are made by 6-axle tractor-semitrailers with an allowable gross weight of up to 49,500 kg (109,127 lb). About 7% of trips are made by 7-axle tractor-semitrailers and doubles with an allowable gross weight up to 59,500 kg (131,173 lb). About 15% of trips are made with vehicles that can carry heavy freight, such as the 8-axle B-train, with an al- lowable gross weight from 62,500 to 63,500 kg (137,787 to 139,992 lb). The remaining 5% or so of trips are made by trucks of diverse configuration, and many of them are made with a special permit, either for an LCV, such as a turnpike double, or to carry an indivisible large or heavy load. Canada has a greater proportion of dense freight and heavy loads because its economy is proportionately more depen- dent on natural resources than the United States. Nevertheless, if the distribution of freight density would be the same in the United States as in Canada, and the United States would adopt the M.o.U. configurations and weights, then it would require about 15% fewer trucks to move the freight that moves in vehicles with 6 or more axles in Canada. This calcu- lation is a very rough estimate. U.S. bridge analysis suggests load restrictions would need to be applied to Canadian vehi- cles. If, however, the vehicles were reconfigured to maximize their weight in accordance with the capacity of U.S. bridges, then the vehicles would have only a slightly diminished capac- ity compared to the Canadian vehicles. When Ontario and Québec allowed 16.2-m (53-ft) semi- trailers in 1994, 5 years after the effective date of the original M.o.U., they allowed only those semitrailers longer than the prevailing length of 14.65 m (48 ft) if they met the exact re- quirements of the M.o.U., so they were only allowing a tan- dem or tridem axle group. Semitrailers with other axle groups were restricted to 14.65 m (48 ft), which quickly limited their utility. Many carriers use a van semitrailer as a general-purpose vehicle, regardless of its number of axles. So, a tridem semi- trailer will take a load that uses all or a substantial part of the weight capacity of the vehicle. However, a similar load may not be available for the return trip, so the vehicle will take a load that could otherwise go in a tandem semitrailer. This improves the utilization of the tridem and diminishes the need for tandem semitrailers. However, this was not possible at a time when tandem loads were increasingly being pack- aged for 16.20-m (53-ft) semitrailers, so the utilization of van semitrailers that were not of an M.o.U. configuration was less than ideal. Ontario and Québec subsequently realized the necessity to allow all semitrailer configurations in regulation and with a secure future length of 16.20 m (53 ft), so that a carrier could optimize the utilization of all vehicles in its fleet. 3.4.2 The Need for Uniform Definitions It cannot reasonably be expected that a desired outcome will be achieved if terms in which vehicles are described have different meanings in the regulations of different jurisdic- tions. The terms include those for vehicle configurations, axle groups and axle arrangements, dimensions, components, and anything else relevant to description of a vehicle. The M.o.U. included a set of definitions of terms, and all provinces have adopted these. If the U.S. federal government would set further truck size and weight regulations, these would be interpreted uniformly if it also required states to adopt all the definitions in the federal regulations, in the same manner as the STAA. If a group of states agrees to harmonize aspects of their regulations, then this should also include an agreement to adopt definitions of terms, in a similar manner to the M.o.U. 3.4.3 The Need for a Complete Vehicle Specification When Ontario introduced regulation by its bridge formula in 1970, it was intended that the provincial economy should benefit from the substantial increase in allowable gross weight. It was expected that new configurations would arise 45

to exploit the new form of regulation, but not all those that arose were foreseen. Nor was the widespread use of liftable axles foreseen, with the consequent road damage and risk to bridges that amounted to Can$300 million in additional maintenance costs per year by about 2000. They could not foresee the poor dynamic performance of some of the config- urations, as heavy vehicle dynamics was still in its infancy at that time. It took 30 years for Ontario to start a process to re- vise what it did in 1970, another 10 years for this process to address all configurations, and it may be another 20 years be- fore all the old configurations are finally retired. The M.o.U. provided comprehensive definitions of terms, and detailed and complete specifications for vehicles, to guard against the unexpected outcomes that occurred in Ontario. These vehicles have, generally, achieved the intended outcomes. Some jurisdictions have a tendency to write vehicle specifi- cations as “A vehicle with (so many) axles shall . . .” followed by some general dimensional limits and allowable weights. Such a vague form does not define a vehicle configuration, and may result in a straight truck, truck-pony trailer, truck-full trailer, tractor-semitrailer, A- or B-train double trailer combi- nation, or some other configuration depending on the num- ber of axles and length allowed. Even if the configuration is specified, as more axles are allowed, the number of ways the axles can be arranged within each vehicle unit, and over the vehicle as a whole, increases exponentially. There is a dramatic range of difference in the dynamic performance of the possi- ble configurations, which may have some bearing on the crash rate and the types of crash. Certain dimensions are important to the dynamic performance of some configurations, and these should have strict limits, but this vague form of specifi- cation generally does not address these. If 6 or more axles are available, then some of these axles will certainly be liftable, as is evident in states that allow use of the Federal Bridge For- mula without other constraints, such as in Washington and Ohio, where vehicles with one or more liftable axles are com- mon. Michigan allows up to 11 axles, with allowable gross weight determined simply by the sum of allowable axle group loads, and has vehicles with 5 or more liftable axles. When a vehicle has a liftable axle with an independent sus- pension, the driver sets the load on the liftable axle. Experi- ence in Canada suggests that a liftable axle is usually down when it needs to be down, but it is often loaded less than it needs to be, based on the overall load on the vehicle, so other axles are overloaded. It is possible that the driver sets the liftable axle to that load that makes the vehicle easiest to drive, rather than the load necessary based on the total load on the vehicle. Many load controls are also not very reliable, so the set load may vary during a trip. The actual axle loads arising from the way the liftable axle is set determine the amount of pavement resource consumed on a trip, and the risk to bridges. When liftable axles are used, this will be considerably higher than expected, based on the amount of freight carried and the vehicle configuration. The actual outcome will be far worse than the desired outcome. 3.4.4 The Need to Monitor Outcomes Highway departments put much thought into a new or amended truck size and weight regulation. Once a new regu- lation is in place, vehicle designers, sales personnel, carrier fleet managers, and drivers put considerable effort into look- ing for ways to use the regulation that will give them a com- mercial advantage over their competitors. These people are very innovative and spend a lot of time thinking, so it may not be surprising that the outcomes may not always be those in- tended. It is critical therefore to monitor the effects of the reg- ulations to ensure that negative, unintended consequences can be rectified early. The intention of the B-train specification in the M.o.U. was that vehicles meeting the specification should look and per- form like B-trains. One of the earliest vehicles proposed was es- sentially a jeep dolly towing a 14.65-m (48-ft) semitrailer, which met the then-current B-train specification, but took much more space to turn than a tractor-semitrailer. It was shortly fol- lowed by a tractor-semitrailer with a low-mounted stinger fifth wheel towing a pony trailer, which also met the specifica- tion, but had much less desirable dynamic performance than a proper B-train. Once these configurations were observed, the Task Force on Vehicle Weights and Dimensions Policy moved quickly to change the B-train specification to preclude them. In the first case, no vehicles were built. In the second case, a small number were built, but only in one province. Monitoring the outcomes of the regulations determined the presence of the deviant configurations. The response pre- vented an unintended outcome as it prevented these vehicles becoming numerous, and avoided a need to grandfather those that had been built for the rest of their useful lives. Monitoring the evolution of the fleet resulting from changes in regulation provides valuable insight into the effec- tiveness of a given regulatory initiative. A recent study (88) on the impact of Canadian size and weight regulation change in the Prairie Provinces describes how the new policies have in- fluenced the fleet mix, resulting in more productive vehicles. It also found that when the new policies were implemented, it took 8 to 12 years for the carriers to fully adjust their fleet. 3.4.5 The Need for Dimensional Compatibility A vehicle may travel between jurisdictions if it is within the dimensional limits allowed in each jurisdiction. It cannot travel where it is not within the dimensional limits of a jurisdiction. A fundamental aspect of harmonization of truck size and weight 46

requires that no jurisdictions have more restrictive dimensions than the national standard. This allows vehicles meeting the di- mensions of the national standard to travel in all jurisdictions. A jurisdiction may be more liberal than the national standard, for its own purposes, as it knows that other jurisdictions are not obligated to accept such vehicles. A jurisdiction would always remain at liberty to restrict roads to vehicles with lesser dimen- sions than the national standard in cases where road conditions are not suitable for larger vehicles, such as, for example, in Cal- ifornia, where a number of mountain roads are restricted to semitrailers no longer than 8.53 m (28 ft). Dimensional compatibility must extend beyond overall length, and must also include regulated internal dimensions. U.S. federal regulations require states to allow a semitrailer at least 14.65 m (48 ft) in length, and all states conform to this. However, many states also regulate the semitrailer wheelbase, either directly by a measurement from the kingpin to the last axle, which is most commonly 13.11 m (43 ft), or by another measurement. The 13.11-m (43-ft) kingpin-to-rear-axle is not an issue for 14.65-m (48-ft) semitrailers, or for tandem axle semitrailers. It may be an issue for a 16.20-m (53-ft) semi- trailer with a 3.07-m (121-in.) spread tandem. It is certainly an issue for a Canadian 16.20-m (53-ft) semitrailer with a 3.66-m (144-in.) spread tridem, where a 13.11-m (43-ft) limit on kingpin-to-rear-axle forces the tridem bogie forward fur- ther than even the most forward setting allowed in Canada. California has a maximum semitrailer wheelbase of 11.58-m (38-ft), and Michigan limited the wheelbase of a 16.20-m (53-ft) semitrailer to 12.34 m (40 ft 6 in.) plus or minus 0.15 m (6 in.), so it was simply not possible to configure a semitrailer with fixed axles that could operate legally in both states. Michigan’s rule was also much more restrictive than the Canadian M.o.U. limits. However, it was recently amended, and now provides a range of wheelbase that is close to the Canadian M.o.U., and compatible with California’s limit. Both overall and secondary, or internal, dimensions need to be specified to ensure compatibility of vehicles with the high- way system, and satisfactory low-speed and high-speed dy- namic performance. The dimensions that need to be specified vary with the vehicle configuration. National standards must address all these dimensions. Experience with state regulation of wheelbase suggests that the STAA approach of requiring that no state set a dimensional limit more restrictive than the specified value may not be sufficient to achieve the required outcome. It may also require a general stipulation that no state can regulate another dimension in a manner that would be more restrictive than a nationally specified dimension. 3.4.6 Weight Tolerances By the 1990s, the most common tractor-semitrailer in the six provinces of eastern Canada was a 3-axle tractor pulling a tri-axle semitrailer, where the semitrailer had a single liftable axle ahead of a fixed tandem axle. The semitrailer had some slight dimensional differences between provinces and was al- lowed a gross weight of 49,000 kg (108,025 lb) in Nova Sco- tia and New Brunswick, about 51,000 kg (112,434 lb) in Québec, and about 52,500 kg (115,741 lb) in Ontario. How- ever, Nova Scotia had a legislated gross weight tolerance of 3,000 kg (6,614 lb), New Brunswick had an administrative tolerance of the same value, Québec had a mandatory admin- istrative tolerance of 1,500 kg (3,307 lb), and Ontario had an administrative tolerance at the discretion of the officer, which industry generally considered zero. When the tolerance in each province was added to its allowable gross weight, a tri- axle semitrailer could be operated freely through the six provinces at an actual gross weight of 52,000 to 52,500 kg (114,639 to 115,741 lb) without fear of a gross weight offense, so the configuration was harmonized for practical purposes between the provinces. However, a simple reading of the reg- ulations of the provinces did not exactly spell out what could be done. It is clear that significant tolerances can skew outcomes. The provinces have agreed there should be no published or legislated weight tolerances, and there are now none. They all retain administrative tolerances that are used at truck inspec- tion stations at the discretion of enforcement staff in accor- dance with enforcement policies, to reflect variability in scale equipment. 3.4.7 Winter Weight Allowances and Spring Weight Restrictions Some provinces allow additional weight to be carried dur- ing a defined period of freeze-up during the winter. Some provinces allow winter weights for all vehicles, while others allow them only for a specific commodity, such as logs, in a number of provinces. Winter weight allowances may vary by highway and vehicle configuration and may require a special permit, depending on the province. All provinces impose spring weight restrictions during the thaw period that occurs after a real winter. The provinces have different and distinct approaches to spring weight re- strictions, and the onset and duration varies widely by loca- tion, between and within provinces, depending on the sever- ity of the freeze-up. Québec applies its spring weight restriction to all highways, even though its main highways may not require a weight restriction. It takes the point of view that if vehicles were allowed at normal weight on main highways, some of these vehicles would also operate on other roads where the full weight restriction is necessary, and those roads would suffer undue damage. Consequently, Québec applies the same spring weight restriction to all roads. Ontario built its primary highway system for full loads all year round. It 47

allows travel at legal weights on these highways during the thaw period, but applies a standardized axle weight limit to secondary highways and other roads. Other provinces, such as Alberta and Saskatchewan, may apply a specific weight restriction to axle groups, or to gross weight for a specific highway. By the early 1980s, after a couple of rounds of response by other provinces to Ontario’s change in 1970, the preferred ve- hicle in the Prairie Provinces from the regulations would have been a 7-axle B-train. However, when spring weight restric- tions were considered, an 8-axle A-train was the most pro- ductive on a year-round basis, so this was the configuration of choice for heavy haul. The A-train rear trailer is prone to roll over in an evasive maneuver, and repairing damaged pup trailers was a good business for trailer manufacturers. Winter weight allowances and spring weight restrictions mean that the configuration that can move the greatest weight of a particular commodity in a particular part of a par- ticular province over a whole year is not necessarily the con- figuration that has the highest allowable gross weight in the summer. The actual outcome is not necessarily the obvious outcome from a simple reading of the rules, and the outcome may differ depending on how a jurisdiction imposes the weight allowance or restriction. Winter weight allowances and spring weight restrictions all result in differences from the standard legal weights, which generally serve as the basis for most evaluations of vehicles, and evaluations of their impacts on roads and bridges. 3.4.8 Vehicle Modifications When the truck size and weight regulations change, carri- ers may have to buy new vehicles, or they may be able to mod- ify an existing vehicle to the proper configuration. A new ve- hicle should meet all pertinent safety standards at the time of manufacture so that is not a problem later. Suppose a vehicle is being modified to have a higher gross vehicle weight rating than it was built with. The gross axle weight ratings of the ex- isting axles may not be sufficient for the new vehicle. The structure may need to be reinforced for higher payload weights. The brake system may be modified and may not comply with the current timing requirements of FMVSS 121, and so on. There are many things that might need to be mod- ified so that the vehicle would be equivalent to a newly man- ufactured vehicle. Not all owners might want to spend the amount of money on a vehicle to ensure the job would be done properly. Not all entities that might undertake the work would necessarily understand, or be able to do, all that would be required. When Ontario introduced self-steer tri-axle and self-steer quad semitrailers in 2001, theses could readily be modified from existing tri-axle or quad semitrailers. To ensure that modified semitrailers would be equivalent to a newly manu- factured semitrailer, the regulation required the company doing the work to affix its own compliance label beside that of the original manufacturer, with the new gross vehicle weight rating and gross axle weight ratings. Thus, only a man- ufacturer registered with Transport Canada as qualified to manufacture and modify, a semitrailer in this case, with air brakes would be allowed to do the work. The manufacturer was therefore required to certify that the modified semitrailer would meet the pertinent safety standards at the time the vehicle was modified. 3.4.9 The Scientific Approach The CCMTA/RTAC Vehicle Weights and Dimensions Study produced a set of principles for the configuration of ve- hicles (18), based on a procedure for evaluating the dynamic performance of vehicles. The procedure is straightforward: 1. The vehicle makes a standard maneuver under specified conditions; 2. Performance measures are computed from the responses to this maneuver; and 3. Each performance measure is compared to a correspond- ing performance standard, to determine whether per- formance is satisfactory or not. There CCMTA/RTAC Vehicle Weights and Dimensions Study used seven performance measures (18) that related to the dynamic performance of semitrailers. The seven original per- formance measures are also more broadly applicable to other vehicle configurations. However, some vehicle configurations have critical performance measures that were not included in the original seven, and new performance measures have been developed to address the characteristics of these vehicles. The original seven performance measures, and others developed since, are outlined in Appendix D, with commentary. After the M.o.U. was put in place in 1989, each province also had a range of other configurations, principally truck-trailer combinations. Collectively, the provinces asked, now that tractor-semitrailers and doubles had been configured to ensure they met objective standards for dynamic performance, should other configurations also be treated in a similar manner? The same procedure for evaluating the dynamic performance of ve- hicle was therefore used to add straight trucks and truck-trailer combinations to the M.o.U. in 1991 (40), for Québec to elim- inate Ontario multi-axle semitrailers in favor of the self-steer quad semitrailer (45) also in 1991, and subsequently for the forestry industry in British Columbia and Alberta to work with the provincial governments to identify preferred configura- tions for legal and permit operations at the highest allowable gross weights (50). All provinces have used the same process 48

when adding a vehicle to regulation (53), (54), and when con- sidering a vehicle for a special permit, and they continue to do this. A province’s assessment of a proposed new configuration is not just based on the assessment of dynamic performance, but also on the impacts on infrastructure, on safety, and on the economic benefit to industry and to the province. It is not un- common for a province to reject a proposed new configuration because it perceives deficiencies in the dynamic performance of the vehicle outside the range of the fleet as a whole. How- ever, some provinces use the process to allow vehicles config- ured for weights higher than legal limits to operate by permit on remote highways where they can operate safely. For exam- ple, Alberta and Saskatchewan allow some log trucks a 2.89-m (114-in.) track width. When Canada’s provinces approached the task of harmo- nizing size and weight regulations, many of the axle arrange- ments and configurations that had become common in On- tario were not allowed by most other provinces. The research conducted during the CCMTA/RTAC Vehicle Weights and Dimensions Study showed conclusively that this position was well-justified. The study identified the deficiencies of these ve- hicles in numerical terms. Vehicle manufacturers and carriers had long since reached exactly the same conclusions and un- derstood the characteristics of these vehicles very well, though in non-numerical terms. Thus, the decision not to allow these configurations was quite reasonable to carriers. When Ontario ultimately began to deal with the issue of liftable axles, as dis- cussed in section 2.1.10, manufacturers and carriers again ac- cepted the scientific evidence that the province had very good grounds for their eventual elimination, both as vehicles and for the damage they did to the infrastructure. The process described here is an administrative process used by staff in the provincial highway departments. They all use the same performance standards and essentially the same process. It is not known to be formally documented, though it could be. This type of process is not used widely in the United States, however, it is clearly applicable to any vehicle that would be considered. It is also clear that some of the vehicles that states allow to operate in the U.S. might not be allowed to operate by Canadian provinces, as they are unlikely to meet the perfor- mance standards. Canadian provinces have assessed, in some cases, the same vehicles that would be considered for more widespread use in the United States. The assessment protocols are well established but would need to be reviewed and formal- ized if being used as part of a federal, or even regional, initia- tive to change truck size and weight regulations. Such an assess- ment methodology would allow decision makers to determine preferred configurations and to set allowable weights and lim- its on dimensions critical to performance. There might also be route restrictions, special driver qualifications, a requirement, perhaps, for a B-train over an A-train, and technology or equipment requirements. After all, if the public at large does not like trucks, then they will not like a larger or heavier truck. However, if the larger or heavier truck can be shown objectively to have better dynamic performance than existing trucks, and will reduce the number of trucks by (say) 10%, with attendant reductions in congestion, fuel consumption and emissions, the public might (grudgingly) concede that there might be a ben- efit to the larger or heavier truck. Most members of the public have a range of objections to trucks that relate simply to the fact that they are trucks, most of which have little or no relation- ship to the size or weight of the truck. These issues must be dis- connected from the discussion. Technology for improving safety on large trucks is being introduced, but unless there is a government mandate, mar- ket penetration will depend on industry anticipating a return on investment. Technology could be a prerequisite for allow- ing larger or heavier trucks, to ensure that safety improve- ments occur simultaneously with greater productivity. There have been studies in Canada consistently showing the safety benefits of adopting LCVs. It boils down to adopting policy that encourages safety benefits. Also, the use of technology can be a prerequisite to allowing bigger vehicles (86). 3.4.10 Grandfather Rights In Canada, it has become apparent that when a province changes its regulations to allow a configuration with a higher allowable gross weight than existing vehicles, the new config- uration appears immediately and grows rapidly in numbers. Most examples of the previously preferred configurations dis- appear, though some that are ideally suited for their mission and would not benefit from the new regulation may remain in service for an extended period. A similar result might be expected if the United States would change its size and weight regulations. Suppose, for ex- ample, that a configuration would be mandated nationally at a gross weight of, say, 43,091 kg (95,000 lb), in the same way that STAA mandated the twin trailer combination. This con- figuration would be expected to displace all the diverse con- figurations operating under state permits or state grandfather rights at weights between 36,287 and 43,091 kg (80,000 and 95,000 lb), and may also displace some vehicles with a slightly higher allowable gross weight. The same thing would happen if new configurations would be mandated, for example, 49,896 or 54,431 kg (110,000 or 120,000 lb). Vehicles config- ured under grandfather rights and state permits would quickly diminish in numbers. The new vehicles would be more effi- cient, as they could travel an all highways, and would open up new business opportunities for many carriers. The resale value of the older vehicles would plummet. The grandfather rights of states are perceived as an imped- iment to changes in U.S. truck size and weight regulations. However, there would be no need for the federal government 49

to override any state grandfather rights. Existing state regula- tions would not need to be repealed, nor would permit pro- grams need to be dismantled. The new vehicles would simply render these irrelevant, and they could continue in place until all the subject vehicles had disappeared, when they could be repealed or terminated. 3.4.11 The NAFTA Partnership Canada and Mexico are sovereign nations and partners with the United States in NAFTA, which became effective in 1994. The NAFTA treaty identified that truck size and weight regulations were potentially a barrier to trade, so it provided a mechanism for the three partners to harmonize their truck size and weight regulations. The United States has essentially not made any changes to its size and weight regulations since NAFTA became effective, while Canada and Mexico have made continuous refinements. Canada and Mexico have both gone to considerable lengths to develop their own truck size and weight regula- tions, which, coincidentally, have many similarities, and con- siderable domestic harmonization. Harmonization with the NAFTA partners to the extent possible and with the intent of achieving more uniform transportation efficiency within North America may be a compelling argument for change. 3.4.12 The Institutional Contrast 3.4.12.1 Jurisdiction In Canada, ten provinces and three territories have the au- thority to set, monitor, and enforce truck size and weight reg- ulations. Provincial limits on truck size and weight apply to all roads within a province, except to the extent that a province or local authority may set access restrictions due to roadway design, or weight restrictions due to bridge condition. In the United States, the federal government, 50 states, the District of Columbia, toll road authorities, local authorities, and maybe others, have the authority to set, monitor and enforce truck size and weight regulations. Truck size and weight are closely related, yet the Senate Environment and Public Works Committee controls weight, while the House Transportation and Infrastructure Committee controls size (86). Federal regu- lations apply to the national network, state regulations apply to state roads, and regulations of other bodies may apply to roads they control. Again, there may be access restrictions due to roadway design, or weight restrictions due to bridge condition. 3.4.12.2 Status In Canada, the provinces have been discussing truck size and weight issues together for over thirty years, and have de- voted much of that time to a process of harmonization. They have managed to make large changes without significant or- ganized opposition, except in one province where there was a 5 year delay. Most recent changes have been minor, and highly technical, refinements, which would not be expected to gen- erate opposition. The process to develop proposals is cooper- ative between provincial civil servants and industry, with the provinces ultimately taking their decision by consensus. In the United States, jurisdictions with authority over truck size and weight may have differing views on the subject. For example, states that allow LCVs generally want the LCV freeze lifted, while states that do not allow LCVs mostly want the freeze to remain. The jurisdictions are also subject to enormous pressure from outside groups, from proponents of a specific change, to a wide range of groups strongly opposed to any increase in truck size or weight. For example, the As- sociation of American Railroads will oppose any proposals to modify the current provisions through 2009 (82). The U.S. federal government ex parte rulemaking process can be some- what adversarial. 3.4.12.3 Taxes and Cost Recovery In Canada, there are no trust funds or dedicated taxes. All fuel and sales taxes, license and permit fees, and other income all go into general revenue of the treasury. Disbursements from the treasury are for budget allocations, and there is no relationship between the source of funds and/or expenditures on programs. In the United States, who pays what to whom, and how and where that payment is used, are very significant issues. 3.4.12.4 The Process In Canada, when the provinces began to make changes in their regulations in response to Ontario’s substantial increase in allowable gross weight in 1970, each exercised its sover- eignty and made changes that reflected its own existing form of regulation and the needs and wishes of its strongest stake- holders. When it became evident that the diversity of the changes was making interprovincial trucking more difficult, the provinces agreed they needed a common process that would lead to uniform regulations. Uniformity may not have been achieved, and it may never have been more than an ide- alistic hope. But substantial de facto uniformity has been achieved. It was achieved because the Council of Ministers expected an outcome. The committee that formulated the ap- proach was composed of provincial representatives who un- derstood what the Council of Ministers wanted, and had ac- cess to the provincial deputy minister (the senior civil servant in the department), and through him to the minister. There was never any doubt that something would be done. It was helpful that the research produced results of lasting value and 50

principles that could be, and were, used to configure vehicles, then and since. If the research had not produced meaningful results, the committee still fully intended to harmonize provincial truck size and weight regulations. In the United States, when Congress acted on STAA in 1982, and ISTEA in 1991, there was no doubt that it intended to do something. However, when Congress mandated the CTSW study, there was no clear intention that there would be any outcome, and there has been none. A number of other studies have been done, but none has produced any direct out- come. At this time, the federal government does not appear to have expressed any view on a direction for truck size and weight regulations. The states have may have differing, or strongly differing, views. In the absence of a clear vision and strong leadership, it is difficult to see significant progress to harmonize truck size and weight regulations from the federal level downward. Meanwhile, states continue to make changes that are putting larger and/or heavier trucks on local roads, when the vehicles truly would be more efficient and might op- erate with less risk if they had access to the national network. The longer states continue to develop their own permit systems, the more diverse the national patchwork of size and weight reg- ulations will become. There has certainly been worthwhile progress by some of the regional groups of AASHTO, and their process appears closer to the Canadian process than any federal process. It would seem possible that the AASHTO process could be adapted into something with a mandate like that proposed for the proposed Commercial Traffic Effects Institute, dis- cussed in section 3.3.6.3 above. However, it is difficult to see the federal legislators giving up their role to define size and weight regulations to an administrative and technical body, and the proponents or opponents of change allowing them to give up that role. 3.4.12.5 Opposition In Canada, the process of implementation of the M.o.U. proceeded relatively smoothly. The only delay was due to public concern in Ontario with an increase in semitrailer length and overall length for doubles, which restricted full implementation in the six eastern provinces for five years. The trucking industry supported removal of regulatory dif- ferences, and shippers supported increased truck productiv- ity. The railways were opposed as a matter of principle, but in fact, there is not a lot of real competition between road and rail for most of the freight that moves in Canada. In addition, the railways made intermodal services the single fastest grow- ing transportation sector with trucking companies as part- ners and customers, and were actually the largest single early purchasers of M.o.U. configurations, with one design of con- tainer chassis for all their terminals across the country. In the United States, there are a number of advocacy groups who may oppose proposals to change the truck size and weight regulations. 51

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TRB’s National Cooperative Highway Research Program (NCHRP) Report 671: Review of Canadian Experience with the Regulation of Large Commercial Motor Vehicles examines the process used in Canada to harmonize heavy truck size and weight regulations across the country. The report provides insights on how lessons learned from the Canadian experience might be applied in the United States.

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