Bridge Rating Practices and Policies for Overweight Vehicles (2006)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

21 The truck transportation industry has been concerned with permitting uniformity, because it is viewed as a cause of lower productivity. For example, when the same load is re- quired to have multiple permits, it can be considered a waste of time and effort in applying and reviewing the permits. This chapter discusses several concerted efforts that are expected to contribute to reducing nonuniformity. NEW ENGLAND TRANSPORTATION CONSORTIUM In 1986, five New England area states in the NETC (Maine, Massachusetts, New Hampshire, Rhode Island, and Ver- mont) started to work with FHWA and the Center for Trans- portation Studies at Massachusetts Institute of Technology in developing an agreement on a multistate permit program. In 1987, the five states signed an agreement on a set of permit procedures. This program is documented in the New England Transportation Consortium Handbook (1995), which de- scribes the common procedures for issuing permits for a ma- jority of the nondivisible oversize and overweight trucks for highways administered by the five states (not other agencies in these states). Although the procedures were developed by and for the five New England states, they were established in a way that also allows for other states and Canadian provinces to become participants (New England . . . 1995). The multistage permit program covers a common core of nondivisible oversize and overweight combination vehicles for a single trip permit. These vehicles need to be within the following “envelope vehicles”: Length: 90 ft or less. Height: 13 ft 6 in. or less. Width: 14 ft or less, except for modular or mobile homes. In that case, an additional 6 in. overhang for eaves will be allowed. The greater overhang shall be on the right-hand shoulder side of the highway, mak- ing the case 14 ft 6 in. Weight: 108,000 lb or less, traveling on five or more axles, or 120,000 lb or less, traveling on six or more axles, in addition to other axle spacing and axle weight requirements. A New England multistate permit can be issued by only one of the five states, although it is valid for all of the states. The carrier needs to file only one application (as shown in Figure 9), no matter how many states the load will need to travel through. The carrier is also required to pay all the fees applicable in each of the states in which the load will travel, but only to the state issuing the permit. This procedure can reduce the work load for both the carrier and the states involved, without the loss of revenue. The permit-issuing state needs to be the destination state of the trip if it is one of the five New England states or the entry state or the origin state if the destination state is not one of them. In addition, the single trip permit can also cover the return trip if one is required according to the law(s) of the involved states. This multistate permit program requires the timely co- ordination and cooperation of the involved states. For ex- ample, the program determines the specific route using a map of the routes that can accommodate the vehicles meet- ing the requirements. On the other hand, these routes may change their condition affecting their ability to do so, ow- ing to construction or other reasons. When this occurs, the state with the jurisdiction of the route needs to notify the other states of the situation and provide information on the detour. The involved states also review the practice in a coordinated fashion and revise the program accordingly when needed. ATLANTIC CANADA Atlantic Canada includes four Canadian provinces: New Brunswick, Newfoundland, Nova Scotia, and Prince Edward Island (PEI). A Guide to the Agreement on Uniform Vehicle Weights and Dimensions Limits (2001) has been developed by Atlantic Canada and implemented in these provinces. The guide has two parts: Part 1 contains general limits on vehicle dimensions and axle and gross weights and Part 2 covers the more detailed limits with respect to 10 categories of vehicles. The following implementation milestones were agreed on by the four provinces. • Once implemented, the weight and dimension limits will apply to all vehicles beginning with model year 2003. • Once implemented, the weight limits in Parts 1 and 2 will apply to all existing vehicles that comply with the configuration requirements and dimension limits con- tained in Parts 1 and 2. CHAPTER FIVE EFFORTS POSSIBLY CONTRIBUTING TO IMPROVED UNIFORMITY OF BRIDGE RATING FOR OVERSIZE/OVERWEIGHT VEHICLES

• Once implemented, common administrative and enforce- ment policies and procedures respecting vehicle weight and dimension limits will be adopted by the parties. • On December 31, 2004, liftable axles on equipment from model year 2003 or later will not be recognized in other than tandem-equivalent or tridem-equivalent axle groups. 22 • On December 31, 2005, the automatic application of tolerances on axle and GVW limits, published or not, will be eliminated. • On December 31, 2009, weight and dimension limits that differ from those contained in Schedule A and that have been provided under grandfather or transition pro- grams will expire. FIGURE 9 New England area Interstate permit application form.

23 Note also that this agreement does not apply when the fol- lowing factors are concerned: seasonal weight restriction, weight-posted bridges, route restrictions, and OS/OW per- mits. In other words, this agreement defines common “legal” vehicles in the involved provinces. Nevertheless, this model of regional agreement may offer an inspiration as to which form of cooperation can be effective. It also appears that a na- tional agreement on OS/OW policies for the United States is not foreseeable at this point; however, regional agreements as short-term goals can be a first step toward such an agreement. SOUTHEASTERN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS MULTISTATE PERMIT GROUP SURVEY SASHTO has established a multistate permit group with a fo- cus on vehicle permits. One of the group’s activities was a survey on permit review through bridge evaluation. This is the first effort known to quantify the impact of differences in the load rating procedures between the states. Note also that some of these differences may occur even within a state, be- cause different offices or individuals may perform the work differently based on their own understanding and interpreta- tion of the governing specifications. In this survey, a specific reinforced-concrete beam bridge and a specific permit vehicle were used as a specimen. These assumptions about the bridge were provided to the partici- pating DOTs: • Bridge was built according to their standard construc- tion practices in 1964, • Material strengths used in the bridge matched those in common use in their state in 1964, • There were allowances for rail and curb dead loads, and • There were allowances for overlays. The bridge and the vehicle were sent to 21 SASHTO states to perform bridge evaluation as part of a permit issuance review. Based on the latest information available, 8 of the 21 responded. The returned calculated rating factors from the eight state DOTs varied from 1.00 to 1.28. Although all of the responding states would approve the permit application, sev- eral would impose some requirements, the most common being to limit the travel speed to between 5 and 10 mph to apparently reduce dynamic impact. It is noted that it could be interesting to review the calculations and the computer input and output to understand the exact sources of the different results. Nevertheless, this effort has pioneered quantification of nonuniformity in bridge evaluation for permit review. WESTERN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS GUIDE In 2004, the Western Association of State Highway and Trans- portation Officials (WASHTO), which includes 18 western states, issued the sixth edition of its Guide for Uniform Laws and Regulations Governing Truck Size and Weight Among the WASHTO States (2004). The first edition of the document was adopted in 1990. This guide is meant to provide directions toward uniform practice in truck size and weight among WASHTO states, although the document also states that each jurisdiction may require some exceptions based on road configurations and local issues. As a result, each jurisdiction maintains the right to develop special exceptions to these rec- ommendations. The minimum standards, however, are ex- pected to apply to the Interstate and primary routes, and any other road that a state may determine as appropriate. WASHTO continues to encourage individual states to in- corporate, to the extent possible, the recommendations of the Guide into the laws, regulations, and policies of all the WASHTO states, to accomplish increased efficiency of inter- state truck transportation in the WASHTO region. Note also that the WASHTO Guide (2004) covers not only vehicles in regular operation (i.e., legal vehicles), but also per- mit vehicles. This is one of the major differences between this document and the one for the four Atlantic Canadian provinces (A Guide . . . 2001). Nevertheless, the latter has specified milestones, and some of them have been completed. Furthermore, Atlantic Canada is now in the process of devel- oping a similar agreement for permit loads. ILLINOIS DEPARTMENT OF TRANSPORTATION LOAD AND RESISTANCE FACTOR RATING SURVEY The AASHTO Guide Manual for Condition Evaluation and Load Resistance Factor Rating (LRFR) of Highway Bridges (2003) is a relatively new set of AASHTO specifi- cations. Although relatively less experience has accumulated with this manual, it should have an impact on bridge load rat- ing and bridge evaluation for permit review. Thus, the effort of the Illinois DOT (ILDOT) regarding the new specifica- tions is discussed here. In 2004, the ILDOT conducted a survey on DOTs’ usage and perspective concerning the LRFR specifications. A ques- tionnaire was issued to the states in the Virtis/Opis/BRASS User’s Group. Of the 40 states surveyed, 32 (80%) re- sponded, with 28 reporting that they have reviewed the spec- ifications and 4 saying they have not. Fifteen states reported having used the specifications for load rating, whereas 17 have not. A total of 275 bridges in the country had been rated using this new set of specifications. However, 209 of the 275 bridges are in two states, with just 66 in the other 13 states. It appears that the new specifications have not been widely used, except in two states. Of those states that had used the code, seven found that the ratings were lower than those using the current AASHTO MCEB (2000), two reported about the same, and three noted that they could be higher, the same, or lower. When asked

whether the state would be more or less likely to use the new specifications, 12 said more likely and 17 said less likely. How- ever, when asked the same question but with the additional con- dition that Virtis could be used to apply the new specifications, 22 states said more likely, whereas 4 still said less likely. AASHTO BRIDGEWARE Virtis is an AASHTO BRIDGEWare product that can be used for bridge load rating and bridge evaluation for permit review. It has the graphical tools to speed preparation of the data and application of the results. It uses the Wyoming DOT’s program Bridge Rating and Analysis of Structural Systems (BRASS) as its analytical engine for load rating. Another important feature of Virtis is its integrated database where rating inputs and out- puts can be readily stored, reviewed, and reused. This feature can make bridge load rating and bridge evaluation results more uniform, because of the repeated use of the same data with min- imal updating. Through the comprehensive database and other interactive functions, the user may provide a 3-dimensional de- scription of a bridge superstructure. These bridge data can then be used by a variety of girder-line, 2-dimensional, or 3-dimen- sional analysis packages for permit and routing review. As discussed previously, a number of states have started their implementation of Virtis, which requires that a large amount of information be loaded in the database. The payoff for this loading is that detailed information on the bridges within the jurisdiction will be available electronically. As a result, a higher consistency of bridge evaluation for permit review can be expected. UNIFORM OVERDIMENSIONAL AND OVERWEIGHT PERMIT POLICY PROPOSED BY SPECIALIZED CARRIERS & RIGGING ASSOCIATION The SC&RA is an organization representing member com- panies involved in transportation of oversize and overweight items. From a viewpoint of carriers, and with consideration to state agency positions and practices, SC&RA developed a uniform overdimensional/overweight permit policy as a ba- sis for a position on uniformity in permit policy. This policy is presented here. 1) Any state, which, based on safety considerations has es- tablished limits in excess of those found in this proposal, should continue such limitations and practices. 2) Routine Issue: This refers to any overdimensional/over- weight permit that would not exceed provisions covered by the Uniform Permit Policy. a) Height—Limited by route only. b) Length—Routine issue up to 120 ft. c) Weight—Routine issue for combinations not to exceed 22,000 lb per axle and/or combination weights as follows: Axle Weight (in lb) Single (Dual Tire) 22,000 Tandem 46,000 Tri 60,000 Trunnion 60,000 24 d) Width—Routine issue up to 14 ft wide. e) Trunnion Axle—A short axle pivoted at or near its mid-point. Normally used in pairs in conjunction with a walking beam in order to achieve two axles of oscillation. 3) Uniform Permit Information A uniform application form for permits is to be used by every state which shall be valid on a single trip for a mini- mum of 5 days excluding holidays. There shall also be a system in every state in which revisions or extensions may be obtained. 4) Blanket Permits and Self-Issue Endorse the concept of Blanket Permits by states on an annual basis. Usage would be available to all domiciled and nondomiciled motor carriers. Self-issue permits would apply to single trips only. Self-issue permits would be completed by the holder of the self-issue forms after communicating with the ap- propriate governing agency. Usually, a permit number routing of some other specified piece of information is given to each person completing the form. 5) Sign and Flag Uniformity Loads exceeding 8 ft 6 in. will have appropriate signs. All overdimensional loads will require signs. Required load signs should be the following dimensions: 7 ft wide by 18 in. high with black letters 1-1/2 in. wide and 10 in. high on yellow background reading “OVERSIZE LOAD” in front and rear locations. 6) Escort Vehicle Requirements a) Length—One rear escort after 90 ft overall length on less than 4-lane highway and after 110 ft on 4 or more lane highways. b) Width—One escort required on all loads when in ex- cess of 13 ft wide. Additional escort required on less than 4-lane highways when in excess of 14 ft wide. c) Height—One escort required in excess of 14 ft 6 in. loaded height. d) Weight—No routine escort service required. e) Escort vehicles shall be equipped with two roof- mounted 18 in. red flags. Whenever the vehicle is es- corting a load requiring the overdimensional load sign, the escort shall display a bumper-mounted yellow 14 in. × 5 ft sign reading “OVERSIZE LOAD” with black letters 8 in. high and 1-1/2 in. wide. Wherever special lights are required, a revolving amber dome light, meet- ing the requirements of SAE J845, mounted in the cen- ter of the vehicle roof, shall meet the state’s special lighting requirements. 7) Periods of Travel Under Permits a) Overweight loads only: overweight loads that are not overdimensional and can flow with the traffic shall be allowed continuous travel. b) Overdimensional loads 10 ft wide or less shall be al- lowed continuous travel. c) Overdimensional loads exceeding 10 ft wide shall op- erate in daylight hours only. d) Vehicles under permit shall be prohibited from travel on the following holidays: New Year’s, Easter, Memorial Day, Independence Day, Labor Day, Thanksgiving and Christmas. SC&RA recognizes that there would be modifications by states to this uniform policy; however, this can be a founda- tion toward enhanced uniformity for the OS/OW permit prac- tice. In item (3) of the uniform policy, a concept of uniform permit information is proposed toward the direction of a uni- form permit application form. Figure 10 displays SC&RA’s proposed information form. On the other hand, SC&RA does recognize that each state has its own forms for a variety of reasons.

25 ELECTRONIC MODELS FOR BRIDGES AND ELECTRONIC SCREENING In chapter four, it was noted that a majority of the states re- sponding to the survey (25 of 44) indicated favorable positions for having electronic bridge models for evaluation. The ad- vantages of this better practice can be summarized according to Table C4-1A as follows: ease, high speed, consistency, and permit-vehicle precision for bridge analysis. These advantages result in a number of positive outcomes. • Uniform modeling leads to uniform review results, • Reduction of modeling effort allows for the considera- tion of more options in permit review and thus a higher probability to approve permits, and • Reduction of turnaround time for permit issuance. These following states reported having electronic models for 90% or more of the state bridge population: Connecticut, Illi- nois, Iowa, Kansas, Minnesota, Oklahoma, Pennsylvania, South Dakota, Washington, Wisconsin, and Wyoming. In addition, electronic screening can be used for reviewing permits not requiring bridge evaluation and has similar advantages. Note that some electronic screening software programs are also applicable for those permits requiring bridge evaluation. According to the survey results and other sources, these states have this capability: Alabama, Nebraska, Ohio, South Carolina, South Dakota, and West Virginia. SOUTHEASTERN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS MULTISTATE PERMIT PROGRAM In 1996, SASHTO established a multistate permit agreement among its member states (“Multi-State Permit . . .” 2000), to “ease the burden of obtaining state oversize/overweight FIGURE 10 SC&RA proposed uniform permit information required.

documents for the trucking industry.” This agreement covers single trip permits for nondivisible loads. The member states currently participating in the program are Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, Missouri, Ohio, Oklahoma, North Carolina, South Carolina, Virginia, Tennessee, Texas, and West Virginia. The permit vehicle is required to be within the so-called “envelope vehicle,” which is defined as follows: length  100 ft (51 ft for outer axle measurement), height  14 ft, width  14 ft, GVW  120,000 lb, steering axle weight  12,000 lb, single axle weight  20,000 lb, tandem axle weight  40,000 lb, and axle group weight (three or more axles)  60,000 lb. One permit is valid for traveling in all participating states. Thus, multiple permits from different states will not be needed for an interstate trip. Representatives from these participating states meet twice each year to get feedback from the states and industry to fur- 26 ther improve the program. This group is also considering adopting the WASHTO envelope vehicle so that the same ve- hicle can be permitted in both regions. Note also that the group is working on other issues that can benefit the trucking indus- try, such as a common envelope permit vehicle for both SASHTO and WASHTO states, uniform escort certification, uniform hours of movement for permit loads, and online per- mitting (R. Braden, personal communication, 2005). OTHER The questionnaire used in this study also solicited additional information and comments that the state-level agencies might have on the subject. Tables C5-1A and C5-1B cite the com- ments received for the United States and Canada, respectively. The required follow-ups for more detailed information have been done and the results have been included in this report.