Routine Highway Maintenance: The Relationship Between Cost and Condition

When transportation agencies prepare a design for new highway construction or major improvements to existing highways, the life-cycle, agency, and user costs are considered in project design decisions. However, when highway projects are completed, maintenance budgets are rarely adjusted to accommodate the routine maintenance of new lane miles. Maintenance budgets thus often do not keep pace. Even if budgets per lane mile remain relatively constant, the number of vehicle miles traveled per highway mile increases. The growing disparity between maintenance budgets and maintenance requirements leads to difficult choices for maintenance priorities. Concerns about safety and mobility tend to trump preservation of capital investment. This paper presents a study of the relationship between maintenance cost and performance. Using data from the state of Wisconsin and regression tree analysis, the study identified physical, environmental, operational, and socioeconomic parameters that influence maintenance costs for asphalt and concrete pavements, shoulders, litter pickup, vegetation control, and ditches. Equations were determined for estimating the annual cost for maintenance of state and interstate highways in jurisdictions responsible for the upkeep of 100 to 900 lane miles.