Friday, July 1, 2016

On protected bike lanes and incomplete streets

Not too long ago I wrote about death of Allison Warmuth, killed on the streets of Boston by a Duck Tour vehicle. Last summer, it was Anita Kurmann, killed by a driver of a large semi truck. Last week - Amanda Phillips, killed by another inattentive driver (Interestingly, all women - are they more vulnerable?). 

Whenever a bicyclist gets killed, there's an outcry from bicycling advocacy community to install more protected bike lanes in the city. This demand is certainly well-intended. The number of bicycles on streets has been growing quickly in the recent years but the necessary infrastructure is still lacking. Even when the city finally builds new bike lanes, what we usually get is this:
A DZBL in Boston (From

The picture shows a very typical DZBL - a Door Zone Bike Lane. Just two stripes of paint and a few bicycle symbols are supposed to protect you from 3000lbs vehicles moving at over 40mph. Either someone in the city of Boston has absolutely no imagination or simply doesn't care. If you still don't see where the problem is, try riding your bike there. You will face cars passing you at a very intimate distance on your left and car doors randomly swung open in front of you on your right. In other words, the city could save money by not painting those two stripes at all and the effect would likely be the same.

Therefore, we complain. And sometimes, we get more. More paint, that is. Just take a look at this magnificent "protected" bike lane in Allston:
 A paint-"protected" lane in Allston (By Steve Annear from

Is a little bit more paint going to keep you safe? We know it won't and this is why bicycle advocacy groups call for true protected bike lanes. In a simplest form, these could be painted on the street, but right between the parked cars and the sidewalk. Next, we just need a simple barrier, such as a concrete, non-continuous curb (a "curbed dashed line") from the street side. Otherwise, you can be sure drivers will park their cars in the bike lane. Ideally, we should simply follow the excellent street design guide by
As you can see, the guide suggests that on streets with a maximum vehicle speed of 30km/h (20mph) no separate bicycle infrastructure is needed. Once the speed goes up to 40km/h (25mph) you should provide simple painted lanes (Note - between the parked cars and the sidewalk!). On streets where vehicles move at up to 60km/h (40mph) curb-separated lanes for bicycles should be included. Then finally, when cars move faster than 70km/h (45mph), fully separated (protected) bike lanes should be present. Now, considering that on most city streets in Boston Metro Area drivers easily reach 30-40mph, we should see protected bike lanes pretty much everywhere. This should make bike activists very happy, cyclists safe and drivers out of the way. Right?


Here is the problem. We hear lots of advocacy about adding protected bike lanes everywhere. But every straight section of the street has to end at an intersection and that's why a street with a protected bike lane but an unprotected intersection is only a half-baked solution.

In fact, such a street could be potentially much more dangerous for bicyclists that a street without any bike lanes. How come? Picture a scenario where a cyclist rides in a protected bike lane, away from cars. Most drivers wouldn't even register his/her presence, especially if he/she is hidden behind a line of parked cars. Now this cyclist approaches an intersection that has no protection, only a few stripes of paint to bridge bike lanes on both sides. Motorists will likely be unaware of any bicyclists entering such intersection. Collisions will be imminent.

On the other hand, if that street had no bike lanes at all, cyclists would have to share the road with cars - certainly a very unpleasant and stressful scenario for most of us. Yet at the same time, the situation will remain the same at intersections, where drivers will have to pay as much attention to cyclists as they do at those straight sections of the road.

Therefore, no street is complete with a protected bike lane but without protected intersections.

We know how such intersections should look like. Massachusetts has prepared a new street design guide that looks very promising and incorporates the best Dutch design practices. The problem is - we still have to start using it.
A complete intersection (Source:
The main obstacles in implementing such solutions are the cost, available space and public push back. I'm not going to discuss the cost here but space is widely available on most main intersections. It's because our main streets look like an airport runway - they are wide. The key to a protected intersection are the four oval islands that reduce the turning radius for right-turning cars. No more cutting corners. On a protected intersection you would need to take a nearly full 90 degree turn before your path intersects with a bicyclist coming from your right. Had Mass Ave/Beacon St intersection been built this way, Anita Kurmann would be still with us.
Of course, adding such islands means that the space for cars gets reduced and some parking would have to be removed. This shouldn't be a problem as those spots right next to the intersecting roads are illegal anyway (Cars parked that close to the intersection block the view).

When it comes to smaller intersections, such as those with a connecting side street, likely the best practice would be to simply raise the crosswalk and the bikeway to the sidewalk level, thus creating a bump in the street that would force drivers to slow down. Not only this would be safer for pedestrians and cyclists crossing this side street, but also for drivers merging with traffic on the main street - they would need to slow down, stop and look around before entering the intersection.
A speed bump and a crosswalk in one - traffic calming measure and a safe way for pedestrians to cross the street.

There are many good practices we could use to stop people from being killed by cars on our streets. Protected bike lanes are one of them. Just don't forget to protect bicyclists at intersections as well.

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