Economic Effects of Lifting the Spring Load Restriction Policy in Minnesota

Abstract

Spring load restrictions (SLR) regulate the weight per axle carried by heavy trucks during the spring thaw period. This policy aims to reduce pavement damage caused by heavy vehicles and extend the useful life of roads, but it also imposes costs on the trucking industry due to detouring or increased number of truckloads. Although the policies have been implemented for many years, their resulting economic effect has been unclear. The Minnesota Local Road Research Board (LRRB) and the Minnesota Department of Transportation (Mn/DOT) sponsored a cost/benefit study of spring load restrictions in Minnesota. The study, based on the results of surveys of industry costs, a pavement performance model, and a freight demand model, concludes that the benefits of lifting the existing SLR policy outweigh the additional costs. Roadways operating at 5-tons require additional study; however, current analysis warrants repealing SLR and keeping roadways operating year-round at 9-tons. The cost of additional damage should be recovered from those who benefit from the change in policy.