The Federal Lands Highway Branch of the Federal Highway Administration (FHWA) has used the California-type profilograph to evaluate ride quality of new bituminous pavements for ten years. During this period, the acceptance plan used by FHWA has evolved without specific attention given to specification limits and to the types of pavements to which the plan is applicable. The purpose of this paper, which is part of a larger study, is: to determine the extent to which a pavement overlay can be expected to improve ride quality. To determine what ride quality requirements (specification limits) to incorporate in pavement overlay contracts, and to determine the effect horizontal and vertical alignment, number of overlay lifts, and ride quality of the existing pavement have on the final ride quality. This study concludes that single lift pavement overlays improve ride quality by approximately 50 percent per lift. It is also concluded that horizontal and vertical alignment play a major role in the attainment of ride quality. Specification requirements for upper limits for profile index and required percent reduction in a profile index are proposed. (A)
Abstract