MOTOR VEHICLE SIZE AND WEIGHT CONSIDERATIONS

In 1992, 6 million medium and heavy commercial trucks in this country hauled freight a total of 152.5 billion miles, nearly 7% of all vehicle miles of travel (VMTs) that year. These VMTs are growing at an annual rate of 2.5%, and the VMTs of combination-unit commercial trucks are growing at an even higher rate (3.5%). Currently, trucks routinely account for close to 40% of the traffic mix on certain segments of interstate highways and at certain times of the day, and overall traffic density frequently approaches or exceeds maximum free-flow capacity limits. It is anticipated that the truck portion of the traffic mix will continue to increase. Simultaneously, truck accidents and fatalities are rising, as is public concern about this trend and the increasing disparity in size between passenger vehicles and commercial trucks. Against this backdrop, strong political debate will be generated by economic pressure to increase the maximum allowable limits for truck size and weight, to improve productivity improvements, and to handle the large-and-growing highway volume. Achieving this seemingly straightforward goal will not be simple. Several potentially conflicting public policy issues are involved.