How Protective are Protected Bike Lanes?

Protected bike lanes are popping up everywhere in the Boston area and around the country. These newfangled facilities, where the bike lane is separated from travel lanes by on-street parking or flexible posts, are generally popular among bicyclists because they feel safe and, well, protected.

But how well do they really protect you, the bicyclist?

Protected bike lane on Massachusetts Avenue, Boston, with car parked in the buffer zone.
With car improperly parked in the buffer zone, the protected bike lane is within reach of opening doors.

At Intersections
When a protected bike lane crosses a street there is no separation between bikes and cars. Intersections normally have clear rules about who gets to go first and who must wait. The first U.S. implementation of protected lanes, Ninth Avenue in New York, in 2007, had separate traffic signals for bikes. But hardly any of its imitators, and none in the Boston area, use this design.

Instead, when the signal turns green, you are allowed to go straight, even though motorists are allowed to turn right, directly across your path. Cambridge asks drivers to “Please make sure to look for and yield to bikes when entering or exiting a driveway or when turning at an intersection.” Boston tells drivers, “Do not make abrupt right turns in front of bicyclists; check to your right and behind you to be sure there are no bicyclists.”

But beware! Some drivers will yield, but many will not. Stopping and looking back and to the right in advance of every right turn is not part of the normal rules of the road, despite what Boston and Cambridge advise, and is not something drivers are taught. Even if they stop and yield to a nearby bicyclist, often drivers will not wait for a line of bicyclists approaching on the right. Most troubling, large trucks and buses have blind spots to the right rear, and colliding with them can easily be fatal.

In short: it’s not safe to trust that right turning drivers will see and yield to you. At a minimum, you must go slowly and cautiously to make sure that the driver is yielding — and don’t go at all if the turning vehicle is a big truck or bus.

And enforcement won’t solve this problem, because there is no statutory basis to the advice from Boston and Cambridge that right-turning drivers must stop and wait for bicyclists approaching from their right, police cannot cite drivers who fail to do so. In fact, four bicyclists were killed by right-turning trucks in Boston, one in each year from 2012 to 2015, but no charges against the truck drivers were filed.

The statutes says that drivers turning right must first signal intent, then move as close as practicable to the curb or roadway edge (MGL Ch. 90 Sec 14), (yielding for bicyclists and motor vehicles to their right as part of the merging process), then yield to any pedestrians in the adjacent crosswalk. After having safely merged to the right, there is no rule that they must stop and wait for bicyclists on the roadway approaching from behind.

You might think that this Massachusetts statute protects you from turning drivers:

“No person operating a vehicle that overtakes and passes a bicyclist proceeding in the same direction shall make a right turn at an intersection or driveway unless the turn can be made at a safe distance from the bicyclist at a speed that is reasonable and proper.” (MGL Ch. 90 Sec 14).

However, the driver must be overtaking; the statute does not apply if you are the one who is passing. This special Massachusetts rule is simply a clarification of the standard rules on passing and making right turns: Since a right turn must be made from the right-most part of the road, and drivers passing a bicyclist “shall not return to the right until safely clear” of the bicycle ahead (M.G.L. Ch. 89 Sec. 2), drivers may not both pass and turn right at the same time.

Drivers turning right, even on a green signal, are required to yield to pedestrians in an adjacent crosswalk. While they should also yield to bicyclists riding on a sidewalk, it does not apply to bicyclists on the roadway. Moreover, pedestrians have reciprocal responsibilities: “No pedestrian shall suddenly leave a sidewalk or safety island and walk or run into the path of a moving vehicle which is so close that it is impossible for the driver to yield the right of way.” If you ride on the sidewalk, at every intersection you are effectively running into the path of turning cars unless you stop to make sure that there are none approaching that might be turning across your path.

Once you are clear of right-turning drivers, you still have to worry about drivers coming from the other direction making a left turn. You are not protected from them either. They are required to yield to you, but they may be focusing on yielding to cars and not notice bicyclists at the far edge of the road. In congested situations, the cars going in your direction may not be able to make it across the intersection, so they often stop, leaving a gap for  left-turners coming from the other direction. If you pass on the right of one of these stopped cars you are screened cannot see or be seen by the left turning cars until it is too late.

At Alleys and Driveways

When you ride in a protected bike lane you are also unprotected at alleys and driveways. When drivers are turning, there are the same problems as with intersections. Drivers entering the roadway from alleys and driveways must yield to traffic already on the roadway. But they may not realize that the space between the parked cars and the curb is a lane of (bicycle) traffic. And even if they properly yield to you, they must stop and block the bike lane in order to see and yield to the cars on the other side of the parking lane. In congested situations, cars blocking the protected bike lane this way may be a serious impediment to getting where you are going.

From Parked Cars

When protected bike lanes are separated from the travel lanes by parking, there is a buffer zone between the parking stalls and the bike lane. That’s an improvement over ordinary bike lanes, which are frequently within the range of opening doors of parked cars. But without the guidance of a raised curb, drivers may sometimes encroach on the buffer area, putting their doors within reach of you. There are no clear statutes on where drivers must park near protected bike lanes (especially since they are still required by law to park within 12 inches of the curb!).

From Pedestrians

Even if car doors are out of range, you still need to worry about people getting in and out. The City of Boston advises: “After exiting cars, people should look for people on bikes before crossing the bike lane to the sidewalk.” But two sentences later the same web page says: “As always, bicyclists must yield to pedestrians crossing the street.” So if you collide with a pedestrian in the protected bike lane, is it automatically your fault because you were supposed to yield? Where there is a sidewalk, pedestrians are required to walk along the sidewalk, not in the road, and they may only cross the roadway at crosswalks. But what if they need to cross the bike lane to get to parked cars or bus stops? Where will they stop when dashing across when the traffic light is about to change? A bike lane is legally part of the road (unlike a bike path on the sidewalk), but that doesn’t mean pedestrians will treat it that way — which means you need to be extra cautious. At the extreme, when there are lots of pedestrians, you can end up with “a Chaotic Circus Of Dangerous Depravity:”

From Other Bicyclists

You also need to be cautious about other bicyclists. There may not be room for you to safely pass another bicyclist–or for a bicyclist to pass you. The problem may be worse in hilly areas, when speed differences are largest on up slopes–and it’s easy for anyone to go dangerously fast on down slopes. And you also need to worry about wrong-way cyclists coming right at you.

From Snow, Ice, Leaves, and Debris

Because of the narrow space between the curb and parked cars, protected bike lanes need special snow plows. Also, you won’t benefit from the snow-clearing effect of passing cars. Protected bike lanes can accumulate leaves and debris if they are not swept, which requires special equipment. You should be concerned about surface hazards, since falls (not involving another party) are the most common cause of bicyclist injuries. Colliding with the flexible posts that separate the protected bike lane from the travel lanes could also cause a fall.

From Drunk and Distracted Drivers

Even though they may make you feel protected, flexible posts are designed to fall over and cause no damage when hit by a motor vehicle. They provide no protection from a drunk or distracted driver. All of the protected bike lane implementations in Boston and Cambridge use these at places where no parking is allowed.







  1. “Protected” is a false description, and should always be in quotes. If these bike lanes are protected, why are so many people killed by turning trucks?

  2. Actually, the 2007 protected bike lanes in New York were not the first U.S. implementation. Protected bike lanes were tried in Davis, CA in 1967. They were soon abandoned because they proved to be dangerous, as described above. See

    IIRC, protected bike lanes were also tried in Columbus, Ohio adjacent to the OSU campus during the 1970s. They too were soon removed for the same reason. They proved to be dangerous.

    Of course, that history is not stopping their promotion now!

Leave a Comment

Your email address will not be published. Required fields are marked *