Union Square Transit Improvements

The MBTA is planning major service upgrades to bus service in Union Square, and the City needs to do our part to make sure those extra buses aren’t stuck in traffic. In collaboration with the MBTA, the City will upgrade our traffic signals and install new pavement markings to prioritize bus transit. These changes include:

• Installing a northbound bus lane on Prospect Street from Oak Street to Webster Avenue
• Upgrading traffic signal equipment and implementing transit signal priority at the intersections of Washington Street and Webster Avenue, Prospect Street and Webster Avenue, and Somerville Avenue and Prospect Street
• Adding a phase to the traffic signal that gives buses and bikes a head start on Washington Street at Webster Avenue and on Prospect Street at Webster Avenue.
• Adding a phase to the traffic signal on Washington Street at Webster Avenue that gives dedicated time for people driving to turn left from Union Square onto Webster Avenue.

Union Square currently serves 4 bus routes, the 85, 87, 91, and 109, and the MBTA is continuing to make investments in bus service to and through the square. In late 2024, the MBTA's Phase 1 Better Bus Network Service Changes swapped out the 86 for the more frequent 109. More recently, the 85 was part of the Spring 2026 Better Bus Network Service Changes. There are also two new Frequent routes outlined in the Bus Network Redesign Plan, the 47 and the 96. These ongoing route changes and upgrades, combined with the high amount of congestion in Union Square, mean that it's critical for the City to invest in infrastructure that will keep these buses moving, improve the transit experience, and encourage more people to take public transportation.

You can find more information about this work by looking at the plans and the FAQs on this page. Later this year, we will post more detailed updates on the anticipated construction timeline. If you have any questions, please reach out to transportation@somervillema.gov or call 311 (617-666-3311).