Evaluation of Puget Sound HOV Lane Hours of Operation: One-Year Results

This report documents changes in the use and operational performance of the Puget Sound freeway high occupancy vehicle (HOV) lane system one year after the hours of operation for those facilities changed. It also describes the public’s attitude toward those changes and HOV lanes in general. In the summer of 2003, a two-year pilot program began that allows single-occupant vehicles (SOVs) to use HOV lanes on four of the five primary corridors in the region (I-405, SR 167, SR 520 east of I-405, and I-90 east of East Mercer Way on Mercer Island) during the hours of 7:00 PM to 5:00 AM, seven days a week. Interstate 5’s HOV lanes remain closed to SOVs at all times, and between 5:00 AM and 7:00 PM, seven days a week, the entire Seattle-area freeway HOV lane network operates as an exclusive HOV-only system. This report uses data collected before the start of the pilot program, during the first two months of operation after the change in operating policy, and after approximately one year of operation, to describe changes that have occurred as a result of the new operating policy.