Vehicle weight and dimension (VWD) regulations are intended to balance the economic benefits of efficient freight transportation against the costs that large trucks can impose on transport infrastructure. This paper presents models to predict the equivalent pavement loads (a measure of the "cost") per unit payload (a measure of the "benefit") as a function of the gross vehicle weight limit and the intensity of enforcement for the common heavy truck types. The models indicate that there are no optimum gross vehicle weight limits that can yield minimum equivalent standard axle loads per payload. It is noted that the incremental "pavement cost/payload benefit" ratio for the heavier trucks e.g. the doubles, is lower than for semi-trailer combinations. Potential applications and limitations of the models are discussed. (A)
Abstract