With the completion of the interstate system, attention has shifted from building a national highway network to improving, operating, and managing the highway system. Movement has been from construction to cost-effective management of highways. Truck movements are an important issue of concern because of the damaging effects that loads from heavy trucks (five-axle and larger) contribute to pavements over time. It has been determined that heavy trucks contribute, on average, 92% of loads applied to rural interstate highways. However, it has been determined that there is great variance with respect to heavy-truck traffic by route and by region of the country. Use of visual presentations such as maps to highlight the differences in levels of heavy-truck traffic by route becomes an important considerationto pavement managers concerned with maintaining existing pavements and planning for pavements in future projects. Topics also discussedinclude the importance and methods of predicting previous and future volumes of heavy-truck traffic in the estimation of design loadings for highways of concern, future economic trends in the heavy-truckindustry, coparisons of loads imposed by truck type, and the development of load maps using load factors sensitive to roadway type andvehicle classification. This paper appears in transportation research record no. 1272, Pavement management and rehabilitation 1990.
Abstract