Evaluating Alternative Maintenance Strategies HR-1039, 1986

(1986) Evaluating Alternative Maintenance Strategies HR-1039, 1986. Transportation, Department of

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Abstract

Although vehicle registration exceeds 160 million and vehiclemiles of travel continue to increase, resources available to construct and maintain U.S. roads are on the decline. Highway agencies are losing purchasing power because of inflation and a simultaneous reduction in gasoline-tax revenues. The revenue decrease is due to lower fuel consumption arising from the increasing use of lighter and more fuel efficient vehicles. Light passenger vehicles currently represent about 40 percent of the passenger-car population. They are steadily increasing in number and are expected to represent almost 90 percent of the passenger-car population by the turn of the century. Vehicle gasoline economy has increased steadily since 1976 going from an average 12.2 to 14.3 miles per gallon, a 17 percent increase (1). Improvements in fuel economy are expected to continue. The higher labor, equipment, and material costs associated with continued inflation with no commensurate increase in revenue have caused highway agencies to reduce personnel and cut back on expenditures at all levels. Between 1978 and 1982, constant dollar expenditures for roadway maintenance on the state-administered highway system fell from $3,000 to $2,200 per mile (1). The impact of these reductions is compounded by increasing maintenance worldoads created by an aging system and the users' growing expectations for higher levels of service. In many highway agencies, the reduction in purchasing power means that highway and bridge maintenance programs are being cut when they need to be increased. For example, the amount of Interstate pavement falling below a psi of 2.3 is doubling every 3 years (1). Also, in its most recent report to Congress on the Highway Bridge Replacement and Rehabilitation Program, the U.S. Department of Transportation reported that almost 24 percent, or more than 135,000, of the nation's bridges are structurally deficient (2). To reverse such trends, financial resources must be made available to highway agencies. To get these resources, highway administrators must show the consequences of poor roads to those responsible for distributing public funds. Diminishing resources demand methods to select the best balance between maintenance expenditures and maintenance service levels. This study addresses a specific facet of this need, i.e., a methodology that can be used to evaluate the consequences to a highway agency and the public of delaying needed highway maintenance.