Literature review : the impact of pavement roughness on vehicle operating costs.

Ride quality as a measure of pavement roughness plays an important role in users’ level of comfort and operating costs. As Swanlund points out in Public Roads, smooth roads cost transportation agencies less over the life of the pavement and result in decreased highway user operating costs, delayed costs, decreased fuel consumption and decreased maintenance costs. Thus, “not only do our customers want smooth roads for comfort, smooth roads cost less for both the owner/agency and the user”. This notion of increased user and agency costs was echoed almost a decade later by Biehler, then president of the American Association of State and Highway Transportation Officials (AASHTO). He stated, “The American public pays for poor road conditions twice—first through additional vehicle operating costs and then in higher repair and reconstruction costs”). He went on to elaborate, “Driving on rough roads accelerates vehicle depreciation, reduces fuel efficiency, and damages tires and suspension”. More recently, The Road Information Program (TRIP) used the international roughness index (IRI) data reported in 2011 by the Federal Highway Administration (FHWA) to assess the roughness of the nation’s roadways and its potential effects on highway user costs. TRIP concluded that 27% of the “nation’s major urban roads” (interstates, freeways, and other major routes in urban areas) were in poor condition with IRI greater than 170 in/mile, and 42% were in mediocre or fair condition with IRI between 120 and 170 in/mile. TRIP also found that “driving on roads in need of repair costs the average driver $377 annually in extra vehicle operating costs,” with additional vehicle operating costs ranging between $178 and $832 annually for urban areas with populations greater than 500,000. It is evident that rough pavements result in increased users’ costs through vehicle operating costs. This report is prepared based on a review of literature to further discuss the extent to which pavement roughness affects the various components of vehicle operating costs. (Author/publisher)