Updating the Pavement Design Catalog for the Washington State Department of Transportation

This paper describes the preparation of a revised pavement thickness design catalog for the Washington State Department of Transportation (WSDOT) that used the 1993 AASHTO Guide, the Mechanistic–Empirical Pavement Design Guide (MEPDG), and WSDOT historical pavement performance data. Selection of the design equivalent single-axle load levels and performance criteria are presented, followed by discussion about how the 1993 AASHTO Guide and MEPDG, version 1.0, results were used to guide thickness choices for the catalog. Importantly, the process also included historical pavement performance, the properties of new pavement materials, regional practices, and construction variability as equally valuable inputs. Emphasis was placed on observations and issues encountered by using the current 1993 AASHTO Guide and the MEPDG. The proposed design catalog has been implemented by WSDOT.