Rapid deterioration of sound level benefits for quieter pavements in Washington state based on the on‐board sound intensity method.

Abstract

This paper provides detailed descriptions of the three test sections of “quieter” pavement evaluated by the Washington State Department of Transportation (WSDOT) using the on‐board sound intensity (OBSI) method and the unique deterioration of those pavements. Within 6 months of installation, OBSI for the test sections were not audibly lower than the control sections. OBSI is the predominant metric used to evaluate the success of quieter pavements in Washington State. Monthly OBSI measurements describe the seasonal variability in measured sound levels and highlight more rapid general sound level increases in the test pavements relative to the control. Asphalt mix compositions and installation procedures used in Washington were similar, or identical, to those used in southern states where the same pavements have been successful. Challenges to the success of all pavements in Washington State include studded tires, frequent freeze‐thaw cycles, and cool summers that encourage lower surface temperatures during installation than in southern states. These challenges are particularly significant for open‐graded friction course OGFC pavements as evidenced by spikes in OBSI measurements following seasonal weather events. Parallels between OBSI measurements and structural durability measurements are described in detail.