A RATIONAL PROCEDURE FOR OVERWEIGHT PERMITS

A rational procedure for calculating safe permit loads for vehicles as governed by the bridges on the route without having to analytically evaluate all the bridges is given. The basis of the procedure is the worst combination of maximum vehicle weights that a bridge is likely to have sustained during its lifetime. With the severest load combination as the datum, maximum increases over legal loads for normal traffic are calculated for control vehicles. Expressions for calculating the modification factors corresponding to two- and three-lane loadings are also provided.