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Alemany Interchange Bike Lanes Project

Project Introduction

The Alemany Interchange Bike Lanes Project proposes striping changes for more safe biking and walking conditions through the “Alemany Maze” including new buffered bike lanes, flexible delineator posts to separate the bikeways from vehicles, high visibility crosswalks and hatched shoulders and narrowed travel lanes to reduce speeding. The project also includes a buffered bike lane southbound on San Bruno Avenue from Alemany Boulevard to Silver Avenue. No changes to parking will be made with this bicycle and pedestrian safety project. The project was approved by the SFMTA Board of Directors at their August 21, 2018, meeting.

June 2020 Project Update
Caltrans’ Alemany Interchange Deck Replacement project is currently underway with the overhead freeway work complete. The SFMTA is currently coordinating with its state partners to receive an Encroachment Permit that will allow SFMTA crews to install the protected bike lanes on the street level within the State right-of-way and connecting to areas controlled by the City of San Francisco. Construction should commence later this summer.

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Project Timeline 
Preliminary Design
Winter 2016 - Spring 2017
Environmental Review
Spring 2017 - Fall 2017
Winter 2017 - Summer 2018
Fall 2018 - Fall 2019
Project Status


The “Alemany Maze,” where U.S. 101, I-280, Alemany Boulevard, Bayshore Boulevard, San Bruno Avenue, and several other local streets intersect, has long acted as a barrier between the adjacent communities of the Portola, Bernal Heights, Silver Terrace, and the Bayview. The SFMTA and the San Francisco County Transportation Authority's Neighborhood Transportation Improvement Program (NTIP) have partnered to deliver a set of safety and access improvements for people walking, biking, and driving through the Maze.

Safety is a significant issue in the interchange area, with several severe-injury or fatal collisions having occurred on the streets in and near the interchange in recent years. The Alemany Boulevard, San Bruno Avenue, and Bayshore Boulevard corridors, which converge at the Alemany Interchange, are all on the San Francisco High-Injury Network. Designated by the City’s Vision Zero initiative, High-Injury Corridors make up 13% of City streets with 75% of severe and fatal traffic related collisions. Future area improvements include a multi-use path and new signalized crosswalks to allow people to safely walk from San Bruno Avenue to the Alemany Farmers Market.

Additional background on this project can be found on the San Francisco County Transportation Authority's Alemany Interchange Improvement Study

Alemany Interchange Proposed Improvements

The Alemany Interchange Bike Lanes Project proposes several improvements designed for more safe walking, biking and driving conditions through the “Alemany Maze.” Key elements of the project include:

  • New protected bike lanes on Alemany Boulevard between Putnam Street/I-280 N off-ramp and Bayshore Boulevard
  • Flexible delineator posts in the buffer space along the bikeways to separate the people on bicycles from motor vehicles
  • Hatched shoulders and narrowed vehicle lanes to slow vehicle speeds on Alemany Boulevard
  • High-visibility crosswalk striping and new roadway markings to clarify vehicle movements on Alemany Boulevard
  • A new buffered bike lane southbound on San Bruno Avenue from Alemany Boulevard to Silver Avenue (an existing SF Bicycle Route)
  • No changes to parking

You can see the future roadway striping for the Alemany Boulevard here. The future striping for San Bruno Avenue can be reviewed here.

Key information about the proposed southbound buffered bike lane on San Bruno Ave between Silver Ave and Alemany Blvd:

  • Street space for the southbound bicycle lane will come from narrowing the existing wide travel lanes - no lanes will be removed
  • The bike lane will not slow or change the northbound 8 - San Bruno Muni bus operations or bus stops
  • The bike lane will improve bicycle lane connections in the area without increasing traffic congestion or removing parking.

Project Status

    The SFMTA Board of Directors approved the project at the Tuesday, August 21, 2018 Board Meeting. The first element of the project, a short bike path at the intersection of Alemany Boulevard and Bayshore Boulevard, was constructed by SF Public Works in November 2018. Installation of the protected bikeways on Alemany Boulevard and the buffered bike lane on San Bruno Avenue was unveiled in March 2021. 


    This project is funded locally from Proposition B General Fund and Proposition K Half-Cent Sales Tax for Transportation.  


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      Contact Information
      Matt Lasky