Trucks require special attention because of the number of people suggesting that any additional investment needs be paid for by the trucking industry. In order to properly evaluate this suggestion, it is important to understand the number of trucks on the road relative to cars, the tax revenues currently collected from this sector and how those taxes have changed in recent years, estimates of the highway damage done by this industry, and the impact of Michigan's heavier than standard 164,000 pound trucks.

102,100 commercial trucks were registered in Michigan in 1993.14 Figure 6 indicates that 42.2% of these were medium sized trucks between 24,000 and 72,000 pounds gross vehicle weight. The standard five axle tractor trailer combination truck, with an elected gross vehicle weight of 72,000-80,000 pounds accounted for 15.4% of the total. Finally, there were 13,390 of the trucks that exceed the federal standard of 80,000 pounds, or 13.1% of the total. 743 of these exceeded 160,000 pounds. While many trucks use Michigan's roads without being registered in Michigan as a base state, this provides some indication of the total. By comparison, there were 5,686,692 autos registered in Michigan, with trucks over 24,000 pounds representing 1.27% of the auto registrations.