WESTRACK—THE ROAD TO PERFORMANCE-RELATED SPECIFICATIONS

WesTrack is a multimillion dollar accelerated pavement testing facility located approximately 100 km southeast of Reno, Nevada. Sponsored by the Federal Highway Administration and the National Cooperative Highway Research Program, the WesTrack project has two primary objectives: to continue the development of performance-related specifications for hot-mix asphalt; and to provide early field verification of Superpave volumetric mix design procedure. To that end 34 test sections were evaluated during the application of nearly 4.8 million 80-kN equivalent single axle loads (ESALs). Performance monitoring was supplemented by two comprehensive laboratory testing programs: quality control/quality assurance testing; and performance testing with primary emphasis on permanent deformation and fatigue cracking. Although the performance-related specification has not yet been finalized, its conceptual framework and system components, including pay factors, are discussed. The WesTrack project has demonstrated the importance of supplementing full-scale testing and performance monitoring with a comprehensive laboratory testing program of component materials and analysis of pavement response to develop a performance-related specification with realistic pay factors for hot-mix asphalt. The paper concludes with a summary of "lessons learned" on the following topics: pavement construction; use of the ignition oven for quality control/quality assurance purposes; driverless vehicle operations; and rehabilitation techniques. (a) For the covering entry of this conference, please see ITRD abstract no. E202467.