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20 carrying capacity. Therefore, the safety of most of the en- SUMMARY tire bridge population deserves adequate attention. How- ever, it is known that not all local bridges are maintained to As discussed in this chapter, load rating involves many the same condition level as state-owned bridges, for a vari- details on which there could be a large variety of available ety of reasons, including the demand on local bridges being approaches. These approaches can lead to different results. relatively lower in terms of level of traffic, so that they do Conversely, the quantification of these differences has not not have to be maintained to a higher standard and the re- yet been done to understand the nonuniformity thereby sources available to local bridges are not as adequate. Table caused. In addition, the number of cases of permit review re- C4-11 shows the responses of the state-level agencies re- quiring bridge evaluation may be relatively small, compared garding load rating for local bridges. Fifteen of the agencies with the number of permits issued without bridge evaluation, do not know whether their local bridges are evaluated us- although the weights of those loads requiring bridge evalua- ing the same procedure used for the state-owned bridges, tion are much higher. Calibrating these various approaches and four agencies of the 44 that responded believe that they along with the computer software programs used can be an are not. effective approach to improved uniformity.