California Partners for Advanced Transportation Technology

This report presents an evaluation of impacts associated with the following changes that were made to the Richmond-San Rafael Bridge as part of a pilot project: (1) opening to traffic of the eastbound shoulder lane on the lower deck of the bridge between 2 PM and 7 PM every day (April 2018) and (2) conversion of the westbound shoulder lane on the upper deck of the bridge into a barrier-separated shared bike/pedestrian (November 2019). Specific elements evaluated include traffic compliance with the shoulder lane open/close periods, use of bridge paths by cyclists and pedestrians, impacts on eastbound and westbound traffic conditions, impacts on incidents, incident clearance times, maintenance activities, and quality of life in Marin County areas near the bridge. These elements are to be used by Caltrans to determine whether the changes should be kept, in whole or in part. Evaluations show that the opening of the eastbound shoulder to traffic has significantly reduced travel times and incidents in Marin County through the elimination of the congestion that used to affect the bridge’s I-580 East approach. In terms of usage, between 150 and 300 cyclists are seen using the upper path in each direction on weekend days, and between 50 and 75 cyclists on weekdays. Pedestrian traffic is usually very low, at less than 25 individuals per day. While the addition of the path on the upper deck has slightly decreased peak bridge capacity and increased travel time variability on the Richmond approach, congestion on the approach remains close to historical averages. Some slight impacts were also found on incident response and maintenance activities. A user survey finally shows a positive perception of the path by cyclists, but a more negative view from motorists.