Rideability Issues for Asphalt and Concrete Specification Modifications

OBJECTIVES: The objectives ofthis study are: I) to summarize and review concerns on the current rideability specifications, with special attention paid to the discrepancy between asphalt and concrete rideability specifications, 2) to analyze the historical data on rideability for asphalt and concrete projects, 3) to analyze the effects of initial rideability from aspects such as driving quality, vehicle operating costs, and pavement service life, 4) to evaluate the necessity for the current specification changes in order to address the concerns and to recommend specification modifications based on research results BACKGROUND: Kentucky currently pays incentives/disincentives on the initial rideability of both asphalt and concrete projects. However, concerns have been raised on the discrepancies between the incentive/disincentive schedules between the asphalt and concrete projects. In addition, the test procedures for asphalt and concrete pavements are different. For example, for asphalt pavements, the Department divides and tests each traffic lane using one-mile test sections, and then transforms the measured roughness to the International Roughness Index (IRl). For concrete pavements, the Department first tests pavement surface with the profilograph on a section of 1,000 linear feet. Only pavements with PI no more than 6 inches will be full pay and may receive an incentive. The length ofthe test section to judge ride quality incentive for concrete is the same as the asphalt, but the adjustment schedule is different. This project will investigate how to make fair payment adjustments on initial ride quality for both asphalt and concrete pavements and recommend specification modification if necessary. FY 2006 ACCOMPLISHMENTS: Historical data such as initial ride quality, paid incentive/disincentive, and the performance of pavements with different initial roughness was collected and summarized. Meetings were held with the study advisory committee and representatives of the industries for their input. FY 2007 PROPOSED WORK: A rough draft of the report will be prepared and submitted for review PROJECTED COST THROUGH FY 2006: PROGRAMMED COST FY 2007: TOTAL ESTIMATED COST: $100,000 $ 50,000 $200,000