Stop Unsafe Bicycling, Walking, and Driving

[A previous version of the following piece was originally sent to the Somerville Journal.  The editor, Dan Atkinson, did not publish it because of the Journal’s policy of not continuing debates between people in the letters column.]

I am writing this piece in response to Alan Moore’s 9/12/13 letter entitled “Treat bicyclists, motorists, and pedestrians equally”, responding to my 9/5/13 letter entitled “Somerville cyclists can earn respect by obeying the law”.

I applaud his response, because this is a teachable moment.

First, to be clear: In my letter, I attacked behavior, not people. I focused on bicyclist behavior, not motorist or pedestrian behavior. I am not concerned with traffic violations that are merely technical, such as a bicyclist who brakes to a crawl while approaching a stop sign and continues without coming to a full stop. I am concerned with unsafe bicyclist behaviors that I see frequently: (1) riding wrong way on one-way streets and rotaries; (2) ignoring stop lights and stop signs; (3) riding on sidewalks in densely-populated areas such as squares; (4) passing pedestrians without an audible signal on a shared path; and (5) riding at night without front lights.

The law is clear. Pedestrians have the right of way. Bicycles are vehicles and their riders are not pedestrians. Bicyclists are required to obey all traffic laws and regulations in the commonwealth (see

The web site provides an additional useful definition:

“Reckless endangerment (noun): the offense of recklessly engaging in conduct that creates a substantial risk of serious physical injury or death to another person. Reckless endangerment is a misdemeanor but sometimes rises to a felony, as when a deadly weapon is involved.”

The physics is clear. A bicycle ridden at high speed is a deadly weapon. The energy contained in a moving object scales up as the square of velocity. If a pedestrian walking at a brisk pace at 3 mph contains amount X of energy, a bicyclist of the same mass riding at a brisk pace (12 mph) contains 16X of energy, and a bicyclist going all out (24 mph) contains 64X of energy (see

To demonstrate the effect, hang a watermelon about the size of a human head from an overhead hook and use a radar gun or mathematical calculations to determine side-swing heights that result in speeds of 3 mph, 12 mph, and 24 mph at the bottom of the swing. Hang a second watermelon of the same size at the same height from the same hook, swing the first out to the height corresponding to 3 mph, and let go. Change watermelons and repeat for 12 mph and 24 mph. Compare the results.

My impression that more than half of bicyclists ignore the traffic laws comes from years of cumulative irritation. To be fair, one notices irritating things more than nonirritating things. To find more objective data, I looked at the “Bicycle and Pedestrian Counting Program” web site at Apparently the program does count bicyclists who are riding illegally, because I read the following in the Frequently Asked Questions section:

Q: Do I count bikers going the wrong way down a one‐way street? A: Yes. Mark the bicyclist under the appropriate [direction of] movement (#1, 2, 3, or 4 [on the map]).

Presentations at the site listed numbers of bicyclists at various locations, but there was no breakdown showing whether or not they were riding illegally. (If there was one, it certainly wasn’t made obvious.) I therefore make the following proposal:

I will donate $100.00 to a charity of Alan Moore’s choice if a two-day bicycle traffic study by an objective third party finds that at all locations studied, fewer than half of bicyclists engaged in any of the unsafe behaviors described in paragraph 2. The traffic study should be taken on one weekday and one Saturday in at least the following locations: Porter, Union, Davis, and Powderhouse Squares; Willow Avenue between Summer Street and Elm Street; and one major intersection along Beacon Street.

If I am wrong, I will not only donate $100 to Alan Moore’s charity, I will apologize in the Somerville Journal, citing the exact figures, location by location, by which I was proved to be wrong. Whether I win or lose, I ask that in the future, the Somerville Bicycle and Pedestrian Counting Program include counts of these unsafe behaviors in their biannual counts, to provide a basis for continuing education and enforcement.

Because motivating people is always an issue with volunteer efforts, I suggest that the City engage pedestrian advocates, such as the Somerville Pedestrian Group, to participate in the unsafe behavior count. A reasonable task breakdown would be for pedestrian advocates to count unsafe behaviors by bicyclists, for bicycle advocates to count unsafe behaviors by pedestrians, and for both to trade off counting unsafe behaviors by motorists.  I will, of course, participate in this effort as a pedestrian advocate.

May I remark, winning this point is less important to me than that these counts be made. I would be glad to be proved wrong. Like many others, I am a bicyclist who does his best to ride safely and within the law. Reckless behavior by bicyclists makes me look bad in the eyes of the Somerville community.