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