Assessment of the I-5 Portland Cement Concrete Pavement in King County - Executive Summary

The Interstate 5 portland cement concrete pavement (PCCP) in King County has been in service for over 40 years, twice its planned design life. As such, I-5 is in need of a rehabilitation/reconstruction effort. This study provides WSDOT information that will aid decision making about the timing, locations, and type of rehabilitation or reconstruction. Extensive pavement conditions/distress data provided by WSDOT were summarized, analyzed, and used to develop visual tools to communicate the condition of the I-5 PCCP. The performances of the non-rehabilitated, diamond ground, and the dowel bar retrofit and diamond ground PCCP were summarized and compared. Use of such information shows that about 66 percent of I-5 in King County is in need of rehabilitation or reconstruction. To further illustrate these conditions, Arc GIS was used to map the various distresses/conditions, and the results suggest which sections of I-5 should be addressed early in the rehabilitation/reconstruction process. The report concludes with a broad assessment of expected I-5 conditions and necessary WSDOT actions for five-year increments (0 to 5 years, 5 to 10 years, and greater than 10 years).