Separated Bicycle Facility

Cycle Track on Vassar Street

Separated Bicycle Facilities, Protected Bike Lanes and Cycle Tracks

The term “separated bicycle facility” is generally used to refer to bicycle facilities that follow street alignments but where there is a physical separation between the bicycle travel area and the motor vehicle travel area, often through barriers or grade separation. They are located between the street and the sidewalk, or between the parking lane and the sidewalk and may be referred to as buffered bike lanes, raised bike lanes, cycle tracks, or one-way bike paths. They incorporate the convenience of riding on the street with the advantages of physical separation from motor vehicle traffic. They are also advantageous because motorists are not likely to drive or park in them; and bicyclists who are apprehensive about riding in the street are more likely to ride in these types of facilities, leaving the sidewalk for pedestrians. Most designs reduce or eliminate the risk of dooring. Perhaps most significantly, separated bicycle facilities provide the necessary support for a greater range of people, including children and those who are traffic-averse, enabling more people to choose to ride a bicycle.

In some cities these facilities are standard, particularly in northern Europe, but can be found in various forms throughout the world. In North America, the number of successful examples is growing rapidly, and there is increasing interest everywhere in implementing this option.

A consideration with the creation of separated bicycle is the additional maintenance required for cleaning and snow clearance. The additional costs are somewhat mitigated by reduced long-term maintenance costs: the bike lane portion receives less wear and tear than the travel lanes; the bike lane accumulates less debris; and the bike lane markings don't need frequent remarking.

Given the policy to promote and support bicycling, the mandate to strongly encourage mode shift, and the fact that separated facilities attract users who might otherwise not choose to bicycle, the case for creating more of these facilities is compelling and City is will continue to evaluate them as an option on a case-by-case basis. One significant constraint is that raised lanes require more space than on-road bicycle lanes.

Cycle Tracks in the Cambridge

Cambridge currently has two completed cycle tracks, on Vassar Street between Main Street and Audrey Street, abutting the MIT campus and on Concord Avenue between Alewife Brook Parkway and Blanchard Road. Additional ones will be added on Western Avenue (construction starting in 2012), and on Binney Street in years following.

What is a Protected Bike Lane?

Protected bike lanes are separate lanes for bicycles that are separated from moving motorized vehicle traffic. The first of these types of lanes in Cambridge that is at the same grade as the road (as opposed to at sidewalk level, as on Vassar Street, Western Ave. and Concord Ave.) has been installed on Ames Street, between Broadway and Main Street.

Protected bike lanes help to make traveling on the road safer for cyclists by being separated from regular motor vehicle traffic. This is not only by being physically separated from moving traffic, but especially because conflicts with parked cars are removed; this avoids “dooring” crashes, as well as those resulting from cars entering or exiting parking spaces (“sideswipes”).

Protected bike lanes also encourage people who wish to ride their bicycles, but do not always feel safe in regular traffic lanes or in regular bicycle lanes.

Separated Bicycle Lane 

As a driver, what am I supposed to do?

Do not block the bike lane

You may never drive or park in any bike lane, including protected bike lanes

Watch for bikes when turning

Please make sure to look for and yield to bikes when entering or exiting a driveway or when turning at an intersection. You should always do this, at every driveway or intersection. 

How should cyclists use protected bike lanes?

Protected bike lanes afford the same access as regular bike lanes. As always, pay special attention at driveways and intersections for turning cars.

It is important to be respectful of all cyclists using the space. Slower cyclists are encouraged to comfortably position themselves to the RIGHT side, so they may be passed by faster cyclists on the LEFT.


The protected bike lanes on Ames Street are wide enough that regular street sweeping and snow plowing equipment will be able to navigate.

Separated Bicycle Lane

For More Information

For more extensive information, including design details and examples from other locations, see the NACTO Cities for Cycling website.

For some interesting reports of bike facilities from around the world, check out the videos at

For more information about bicycling in Cambridge, please contact Cara Seiderman,, at 617/349-4629.