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13 CHAPTER THREE NONUNIFORMITY IN PERMITTING SYSTEMS In the United States, the current weight limit for the National same permit type, different jurisdictions may still have no- System of Interstate and Defense Highways and reasonable ticeably different processes and procedures. Owing to re- access thereto includes: 80,000 lb for GVW and 20,000 lb for source allocation, the processes and procedures used can also an axle, along with the federal bridge formula (Formula B) be different in efficiency, and the accuracy of permit review for axle spacings and axle weights. The federal bridge for- may be affected as well. mula is established to provide a simple means of determin- ing whether or not a vehicle will be allowed to travel without a permit. VARIATION IN PERMIT TYPES AND POLICIES W = 500(LN/N - 1 + 12N + 36) (2) Table C3-1A in Appendix C presents an overview of the where OS/OW permit types according to the state-level agencies in W is the allowable gross weight in pounds on any group of the United States, derived from the responses of state agen- two or more consecutive axles, cies to the questionnaire that can be found in Appendix A. L is the distance in feet between the extreme of any group Table C3-2A includes more information regarding whether of two or more consecutive axles, and bridge evaluation is needed in reviewing the permits. For N is the number of axles included in the group under con- several states, more information was added using the pro- sideration. vided websites or attached documents given in the original responses. Table C3-1A shows a wide variety of permit Another alternative way of presenting this bridge formula is types, in terms of their definitions (e.g., annual, nondivisible, a table with L and N as two variables and W as the function and radius), GVW limit (e.g., 112,000, 120,000, or 200,000 value in the table. Figure 7 shows the bridge formula with lb), dimensional limit, frequency of use (e.g., annual vs. sin- L in the first column and N the first row. The federal truck gle trip permits), etc. weight and size limits have evolved over several decades. A brief history of this evolution can be found in NCHRP Many state-level agencies have two groups of permits with Report 198 (1979). respect to whether bridge evaluation is required or not. Table C3-1A lists the permit types according to that requirement, if It also should be noted that many states have GVW lim- the response so indicated. It is seen that the dividing line be- its different than 80,000 lb. In addition, the states also have tween the two groups varies, sometimes, significantly. For ex- their own laws and regulations to allow those trucks ex- ample, Illinois uses 120,000 lb as the threshold for requiring ceeding the federal limits to travel within respective juris- new bridge evaluation, whereas Iowa has a 156,000 lb thresh- dictions. These laws and regulations were often developed old. Note that the two states share borders. In addition, New without considering other, especially neighboring, states. Mexico allows GVW up to 140,000 lb not requiring bridge Also, they are often made without input from the technical evaluation, but Texas allows cranes weighing up to 200,000 community, such as bridge engineers. As a result, laws and lb without requiring bridge evaluation. They too are neigh- regulations of different states are nonuniform for both per- boring states. mit vehicles and legal loads. Furthermore, within the group of permits not requiring In this chapter, the nonuniformity in permit review and is- bridge evaluation/load rating, there are usually some routing suance is first analyzed regarding the permitting systems in requirements to meet. For example, Iowa uses an annually up- the states. The system here refers to the definitions of permit dated bridge restriction map to route vehicles below the types of the jurisdiction, the process of permit review and 156,000 lb threshold, but Illinois' response did not indicate issuance, human resources allocated to the operation, etc. other specific requirements for vehicles below their 120,000 When an overweight vehicle falls into different permit types lb limit. Although the survey did not ask the basis for the di- in different jurisdictions in which the carrier would like to viding line between the two groups of permits, it is an impor- travel, the permit review processes and procedures can vary, tant factor to understand to improve uniformity in permitting possibly causing different results. Furthermore, even for a OS/OW vehicles.

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14 FIGURE 7 Tabulated federal bridge formula. In addition, the last column of Table C3-1A includes the Table C3-1B is similarly obtained from Table C3-2B. It responses of the state-level agencies to the question whether includes the types of OS/OW permits issued in Canadian other agencies within the jurisdiction also issue OS/OW per- provinces and other jurisdictions. For each province or ju- mits. Approximately half of the state-level jurisdictions also risdiction the number of permit types appears to be similar have other agencies (including local agencies) issuing to that of the United States state-level jurisdictions shown OS/OW permits. The local agency permits are for the roads in Tables C3-1A and C3-2A. The overall situation is also and bridges within their own jurisdictions. For example, Al- similar to that in the United States. Conversely, under abama, California, Illinois, Iowa, Kansas, Massachusetts, the North American Free Trade Agreement (NAFTA), Minnesota, New York, North Carolina, and North Dakota all some of these permit vehicles may be allowed to travel have local agencies issuing permits. This situation perhaps in the United States, which can worsen nonuniformity in has made nonuniformity even more visible. permitting.