Initial Plan for the 4th Street Bridge Temporary Emergency Transit Lanes

Project Introduction

As traffic congestion returns, the SFMTA is working to support San Franciscans who continue to rely on Muni to get to work and essential appointments during this pandemic. If just a fraction of the people riding transit before the crisis begin driving alone, traffic congestion will be so severe that it could paralyze the city’s economic recovery. Without action, transit-dependent San Franciscans will bear the costs of traffic congestion with longer travel times leading toan increased risk of exposure to COVID-19 on slower, more crowded buses.

Along with other key locations across the city, the SFMTA is proposing to install a temporary emergency transit lane on the 4th Street Bridge, addressing a key bottleneck that delays the T Third line. As the SFMTA prepares for the return of T Third service, installing the dedicated transit lane would allow trains to move more quickly over the bridge without getting stuck in traffic. This means that Muni can provide more frequent T-Third service and greater capacity with the same number of vehicles.

Locations of proposed temporary transit lanes were chosen based on current ridership and travel time data. Providing service improvements to customers on Muni routes that serve neighborhoods with high percentages of people of color and low-income households is a top priority.

Bus Routes and Rail Lines

KT: K Ingleside-T Third Street

4th Street Bridge 

On 4th Street between Berry and Channel, the full-time transit lanes will run northbound and southbound. Currently, there are two southbound and one northbound lanes. Muni tracks share the northbound lane and one of the southbound lanes with all other vehicles, meaning the T Third often gets stuck in traffic, causing delays and bunching throughout the entire line. The proposal restricts northbound traffic by creating a transit and taxi only lane. General traffic would no longer be permitted northbound between Berry and Channel streets. Nearby routes for general traffic heading north from Mission Bay towards SoMa include 3rd and 7th streets.

Going south, the middle lane with tracks will be for transit and taxis only.  The curbside lane going southbound will remain for general traffic.

Additional general traffic and turn restrictions would also be implemented as part of this project:

• Heading east on Channel, no left turn traffic onto bridge
• Heading west on Channel, no right turn traffic onto bridge
• Heading north on 4th Street at Channel, no northbound through traffic onto bridge
• No left turns onto Berry Street from northbound 4th Street

An incremental approach will be used to implement the northbound transit lane to allow time for evaluation. The proposed northbound transit lane will initially only be installed within the existing northbound left turn lane at 4th and Berry, and northbound left turns would be prohibited. Northbound traffic would still be allowed on the 4th Street Bridge during this time. If northbound traffic still causes transit delays despite these initial changes, the full northbound temporary transit lane would be installed between Berry and Channel Streets, the turn restrictions would be implemented at 4th and Channel, and northbound traffic would be prohibited. 

Project Timeline

The project will be considered by the SFMTA Board of Directors in early 2021. Pending approval, installation would follow soon after.

Implementation and Sunset Date

On the 4th Street Bridge, the temporary emergency transit lane would be striped with white paint and “Muni/Taxi Only” stenciling and signage, making it easily reversable if necessary. No red color is proposed as part of this temporary installation. The temporary emergency transit lane on the 4th Street Bridge will automatically be removed within 120 days after the city’s emergency order is lifted, unless there is a public process to make the temporary emergency transit lane permanent.

Outreach and Evaluation

The urgent nature of this emergency calls for putting temporary measures into place, directly on the street. This accelerated approach allows the city to respond quickly to protect public health and support economic recovery while we work with the community to evaluate and make adjustments to the temporary transit lanes as needed.

Areas of evaluation will include, but are not limited to:

• Health and safety benefits
• Economic health
• Neighborhood impacts and equity
• Transit performance
• Traffic safety

Community-based organizations, stakeholders and neighbors will be involved in shaping the framework and process for evaluating and adjusting the emergency transit lanes in real time. Based on public feedback and ongoing, on-the-ground data monitoring of the temporary transit lanes, we can tweak—or even remove—lanes to meet the needs of the community and Muni customers. Both qualitative and quantitative data will be collected after implementation and will inform any changes needed to the transit lanes and whether permanent approval of the lanes should be pursued.

Nearby Work for the Central Subway

In addition to the installation of a transit-only lane on the northbound lane of the 4th Street Bridge, SFMTA staff continue to make progress on construction of the Central Subway project nearby on 4th Street. Crews are currently working on:

• Repainting crosswalks at 4th Street & King Street
• Designing future lane reconfigurations around 4th Street & King Street