Work zones on freeways cause an estimated 24 percent of the nonrecurring delays on freeways and principal arterials . According to the Federal Highway Administration, the purpose of maintenance—which includes restoration, resurfacing, minor widening, and reconstruction—is to keep highways in usable condition not to extend service life. Pavement resurfacing represented just over half (51 percent) of the miles of federal-aid roads undergoing federally supported construction or maintenance in 2001 (figure 8-2), up from about 42 percent in 1997.1
The level of funding applied to highway maintenance is an indirect measure of the amount of maintenance activity and, thus, presence of work zones on highways. Although well-maintained roads are vital to a smoothly functioning transportation system, the maintenance activity may temporarily disrupt the flow of vehicles, causing traffic delays and congestion.
Funding for highway maintenance increased by 15 percent (in constant 1987 dollars)2 between 1990 and 2001 (figure 8-3). The amount of funds disbursed by federal, state, and local governments for maintenance activities totaled $20.3 billion in 2001. This represented 24 percent of total disbursements for highways in 2001 .
1. Chin, S.M., O. Franzese, D.L. Greene, H.L. Hwang, and R. Gibson. “Temporary Losses of Highway Capacity and Impacts on Performance,” Oak Ridge National Laboratory, May 2002.
2. U.S. Department of Transportation, Federal Highway Administration, Highway Statistics 2001 (Washington, DC: 2002), table HF-2, also available at http://www.fhwa.dot.gov/ohim, as of June 2003.
1 1997 is the earliest year for which these data are available.
2 Instead of chained 2000 dollars, constant 1987 dollars are used here because the Federal Highway Administration publishes its data accordingly.