CAMBRIDGE REAR-VIEW MIRROR STICKER CAMPAIGN

Cambridge has encouraged riding in the "door zone" with its bike lanes, and having done that, Cambridge has come up with up with an answer to that problem, the sticker shown below, distributed to residents who apply for resident parking permits. (screen size may vary; actual size about 1 1/4 x 3 inches).

According to the instructions printed on the sticker's face, a motorist is supposed to apply the sticker to the outside rear view mirror, thereby covering up part of the mirror's surface. The sticker tells motorists to watch for bikes while making it harder to watch for bikes. Nice thinking!

Well, actually, only part of the sticker is supposed to be applied to the mirror, but the dividing line is invisible until you actually start to peel off the paper backing -- then you will notice that the front layer comes apart into an inner and and outer part, as shown here.

Most people will decide that the entire sticker including the outside part is what is to be stuck to the mirror. Even for a person who gets past this obstacle and peels away the paper backing layer, there is no way that the transparent plastic sticker with adhesive on the back is smooth enough to allow a clear view in its part of the mirror.

Now, granted, motorists should look out for bicyclists (and pedestrians, and other motorists...); but the City would be in a very interesting legal position if a motorist claimed to have been unable to see a bicyclist -- or an overtaking motor vehicle --   because of the sticker. Or if a motorist was reading the sticker's cheerful message and ran into a tree. To describe the problem in technical terms, no human factors analysis appears to have been applied to this project. It is traffic engineering by English majors, who have never heard of terms such as "perceptual overload" and who cheerfully believe that people will do the right thing if they only are reminded often enough.

From a bicyclists' point of view, the only workable advice is to ride defensively according to the rules of the road, and stay out of the "door zone" if going more than 5 miles per hour. It doesn't matter if 99 out of 100 motorists look before opening the car door, the 100th will get you. And be especially careful when passing cars that have stickers on their rear-view mirrors -- if you ever see any.

But the only examples of these stickers I have ever seen are those which were proudly handed to me by the City's Bicycle/Pedestrian Coordinator. I have never seen one actually mounted on a rear-view mirror. Apparently, the residents of Cambridge have more common sense than the city government has.