Proposed letter in favor of Concord Avenue bike lane

Hello all, you are probably unsurprised to hear this from me, but I like the new bike lanes on Concord Avenue. I ride on them at least 6 times a week (5 days to/from work, plus farm share from Farmer Tim on Sunday), and they reduce stress even for someone as accustomed to traffic as I am.

I was also pleasantly surprised at the quality of the pavement; there are a few imperfect spots, but it is not as bad as I had thought it might be, and I would not hesitate to recommend it to other people.

I’ve heard through the grapevine that people now parking closer to traffic feel that is not comfortable to get in and out of their cars, and why yes, I have biked in that same space many, many, many times, I can see how they might feel that way.  That is sort of the whole point of a protected bike lane, reduce exposure to traffic.  Drivers newly exposed to traffic may feel this rather keenly, but it is a constant risk to someone riding on a street on a bicycle.

One reason to have such a bike lane is that it reduces the overall person-minutes of traffic exposure; it is a net win for that problem. Here are some measurements and estimates that I hope demonstrate this.  I timed myself this evening traveling from Baker to Orchard, and it took 2 minutes. I also experimentally got in and out of a car parked in our driveway and walked around it, and I was easily away from the side of the car in 15 seconds either entering or exiting. That is, each person on a bike traveling that stretch of road is exposed to about 4 times as much passing traffic as someone entering or exiting a car (2 minutes versus 15 seconds to enter plus 15 seconds to exit). If I had to guess conservatively, I’d say that (in one direction) there’s at least 15 bikes per hour between 8am and 10am and again between 5pm and 7pm (60 bikes), plus (really guessing) at least 5 bikes per hour between 10am and 5pm (35 bikes), for a total of 95 bikes, for one direction. I base my rush hour estimate on seeing at least one bike moving in each direction almost every time I commute on Concord Avenue, and they are as much as 2 minutes away from me, and I don’t count because I am the observer, so bikes are 4 minutes apart at rush hour, or 15/hour. 95 bikes times 4 is 380 — if fewer than 380 cars park on one side (or the other) in a given day, then the protected bike lanes result in less traffic exposure. I counted parking spots from Baker to Orchard on the north side (which has more spots) and got 57.  380/57 is 6-and-2/3 — unless the average weekday parking traffic per spot is over 6-and-2/3, we’re better off (fewer people-minutes of traffic exposure) with protected bike lanes. I don’t think there’s that much traffic in those spots. I suspect that the average weekday cars per space is closer to 2, so I could be off quite a bit in my estimates and the protected lane would still be a net win.

This is also just raw traffic exposure, ignoring dooring risk, and assumes that someone parking their car gets in or out of their car without waiting for traffic to clear; time is time, they’re exposed for 15 seconds. Actual cautious-driver behavior reduces this risk whenever there’s any gaps in traffic (it’s easier to find a 15 second gap, than a 2-minute gap).  There are caveats and quid-pro-quos, but none of them results in winning arguments against a protected bike lane; for example, in the old configuration, if no cars are parked, then I would often ride through parking spaces (where the protected lane is now) to increase my distance from traffic — but if no cars are parked, people aren’t exposed to traffic parking their cars.  Or, if there is very high turnover per space, yes drivers are more exposed, but then the risk of dooring becomes high enough that it cannot be ignored.

I do sympathize with people who think parking is unpleasant, and that’s one of the reasons I ride a bike instead — I hate parking, too.  I’m not young, I’m not thin, it’s not a short commute, I do this year round, I keep waiting for more other people to realize that they could do the same.  A protected bike lane removes one of the frequent and otherwise intractable objections that many people have to riding a bike around here.