Secondary costs include paying a larger share of local road maintenance, subsidizing sprawl development along new highways, and health costs from air emissions. The tax burden for local roads is effectively shifted away from state and federal aids onto local property taxes by the current budget proposal, continuing a ten year trend. The SHP claims that expansion of the highway system will relieve congestion, while studies and the experience of states with extensive highway networks demonstrate that congestion relief is minimal and quickly outpaced by newly generated traffic. Ignores Induced Traffic. New highway capacity typically generates extra traffic.
Induced traffic brings congestion back, usually sooner than predicted.
More Heavy Trucks. The draft SHP also estimates that commercial truck traffic will double by 2020, but does not account for associated costs. Heavy truck traffic is a serious highway safety concern. Highway crashes are the leading cause of death for Americans between 15 and 24. Destroys Farm Land and Wetlands.