California Partners for Advanced Transportation Technology

This report evaluates the impacts associated with the following pilot changes that were made on and around the Richmond-San Rafael Bridge: (1) opening to traffic of the eastbound shoulder on the bridge’s lower deck between 2 PM and 7 PM every day (April 2018); (2) conversion of the westbound shoulder on the upper deck into a barrier-separated bike/pedestrian path (November 2019); and (3) conversion of an existing one-way bicycle path on the I-580 West Sir Francis Drake off-ramp overcrossing into a barrier-separated two-way path. Specific evaluations include the level of use by cyclists and pedestrians, impacts on traffic conditions and vehicle emissions, traffic compliance with the eastbound shoulder open/close periods, impacts on incident frequency, types, severity, and clearance times, and impacts on maintenance activities. 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 I-580 East approach. 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. Bicycle traffic on the bridge path is highest on weekends, with an average of 483 cyclists entering the bridge on Saturdays and 355 on Sundays. Weekday traffic is much lower, at around 90 trips per day. Pedestrian traffic is usually very low, at less than 25 individuals per day. Some slight impacts from the addition of the path were also found on incident response and maintenance activities, but no significant impacts on incidents. A user survey further shows a positive perception of the path by cyclists, but a more negative view from motorists. The use of the modified path on the Sir Francis Drake overcrossing seems to mirror the use of the bridge path.