Bus Priority

Cities can make buses travel better by redesigning streets to have dedicated lanes and redesigning signals to give more time to buses. By focusing on places with high delay or high unreliability, the City identifies locations that will benefit from various bus priority strategies. Recent bus priority projects, reports, and studies are listed below.

Dedicated bus lane projects

For each street redesign project, the City thoroughly considers dedicated bus lanes and signal priority in creating the design of the street. You can learn more about upcoming and completed street redesign projects where dedicated bus lanes are/were considered.

Upcoming street redesigns where bus lanes are being considered

During the following street redesign projects, city staff will consider dedicated bus lanes and signal priority. Click links to see the project webpage

Completed street redesigns with bus lanes

We considered and built dedicated bus lanes in the following projects.

State government agencies built dedicated bus lanes in the following projects.

Questions about bus lanes

What is a bus lane?

A bus lane is a part of the street that we have dedicated for buses. To make this clear, we have added things to the street to make it as clear that the lane is dedicated to buses. You will see solid white lines to mark the edges of the bus lane, red lane markings in the bus lane, "Bus Only" text markings, and black and white traffic signs that say "Right Lane Bus Only". 

Why create a bus lane?

Bus lanes make bus routes more reliable and make bus trips faster, especially during times when streets are congested. In Cambridge, this means improvements for riders who use MBTA Routes 1, 62/76, 64, 67, 70, 71, 73, 75, 77, employer and campus shuttles, MASCO M2 buses, and EZRide buses. We create bus lanes because the City's transportation and citywide mobility plans say this is important.

What vehicles can use a bus lane?

Bus lanes in Cambridge are for MBTA buses, shuttle operators, school buses, and emergency vehicles. Some dedicated bus lanes are also shared bus-bike lanes with cyclists sharing the bus lane with bus and shuttle operators.

When can a motorist enter a bus lane?

Motorists can enter a bus lane to access a parking lane or driveway and to turn right at the next intersection.

Where motorists need to access a driveway or parking lane to the right of a bus lane, motorists should enter the bus lane no farther than 50 feet from the driveway or open parking spot. Motorists must yield to buses and cyclists in the dedicated bus lane when making this movement. Motorists entering a driveway should double check for cyclists in the bike lane, too.

Where motorists need to make a right turn to enter a side street, we have designated a place for motorists to enter the bus lane about 100 feet from the intersection. We show that location by breaking the solid white lines and red markings and using a right-turn marking. Motorists must yield to buses and cyclists in the dedicated bus lane and can only turn into the side street at those intersections. Motorists making a right turn should not enter a bus lane until they are at a broken or dashed white line.

Motorists can enter a bus lane to access the general travel lanes from a driveway or side street. Motorists should not drive in the lane.

Can a motorist park, load, or stop in a bus lane?

In most cases, a motorist cannot park, load, or stop in a bus lane.

On Massachusetts Avenue between Alewife Brook Parkway and Dudley Street, there are times of day when you may park or load in the bus lane on the southbound/Porter Square direction side of the street. Street signs will show the hours when parking and loading is allowed.

Priority for buses at traffic signals

Massachusetts Avenue - Implemented 2017

In 2017, the City and the MBTA installed transit signal priority equipment at two locations on Massachusetts Avenue. This equipment allows traffic signals to give a few more seconds of green time to buses so that they can make a green light.

Reports on bus priority in Cambridge

City analysis of bus lanes on Mass Ave Dudley to Alewife Brook Parkway

In 2023, the City reviewed the effect of bus lanes on Mass Avenue between Dudley Street and Alewife Brook Parkway. "The analysis shows that average travel time for Route 77 buses between Dudley Street and Alewife Brook Parkway significantly decreased after bus lanes were added. Bus travel times also became more consistent and predictable throughout the day."

Read the news item: Bus trips on north Mass Ave faster, more consistent with bus lanes

Read the memo: Post-implementation travel time analysis of Massachusetts Avenue

Pioneer Institute's Bus Rapid Transit Report

In 2022, the Pioneer Institute released a comprehensive report on the costs and benefits of bus rapid transit in Greater Boston. This report provides an overview of their study which concluded that bus rapid transit can offer cost-effective benefits as shown through the success of pilot programs. 

Read the report: Bus Rapid Transit - Costs and Benefits of a Transit Alternative

MAPC's "Get it Rolling" Guidebook

In 2021, the Metropolitan Area Planning Council released the "Get it Rolling" guidebook. This is a framework aimed to help transportation stakeholders improve their bus systems and infrastructure, launch pilot programs, and ensure community engagement. 

Read the guidebook: Get it Rolling - A Brief Guide to Mobilize Bus Improvements in Greater Boston

Transportation Research Board-Transit Cooperative Research Program

In 2019, the Transportation Research Board's Transit Cooperative Research Progam published Report #207: Fast-Tracked: A Tactical Transit Study. This study is a snapshot of the quick-build strategies that cities have used to improve travel for people on buses and streetcars. This report included both bus priority projects in Cambridge. To read this report, visit the report's webpage.


The Barr Foundation funded part of the City's Mount Auburn Bus Priority pilot project. The Barr Foundation and partners at StreetFilms reported on the successes of various projects in the Boston area. Click below to watch the StreetFilm

Study on bus delay and unreliability

In 2014 and 2018, the City studied bus delay and unreliability on most bus routes in Cambridge. In the 2018 study, City staff identified locations of concern where bus delay and unreliability are high. In locations of concern, we may desire to install dedicated bus lanes and priority at signals for buses. These locations of concern mapped onto Cambridge streets. Click here to see this map of the locations of concern.

More information

For more information about the City of Cambridge transit program, click here.

For more information about bus priority in Cambridge, please contact Andrew Reker at areker@cambridgema.gov or 617/349-6959.