ABSTRACT
Some major roads in Sweden are being designed to carry a higher vehicle load of 74 metric tons. This is almost 25% higher than the previous maximum legal load. There is no change of the maximum 10 ton axle load, and the 11.5 ton driving axle. Thus, in the elastic world, the change would not incur any changes in the pavement design, as the number of equivalent axle loads will remain the same, provided the freight levels are the same. However, the experience from a previous change of the legal loads showed clearly that sub base layers tended to deform at a faster rate. Hence, the specifications for sub base layer materials were changed with tougher criteria for the gradation curve. The present paper compiles experience from a failed mining truck road to address issues that may affect specifications for unbound materials.
