It’s final, and the math has been corrected. Here’s the final version of the Boston Cyclist Safety Report. And here’s the final version of the corrected chart showing various bike/car factors contributing to accidents:

Bikers, let’s take control of our safety:
1. Don’t “salmon” (ride against traffic)
2. Don’t run red lights and stop signs
3. Make yourself visible. I know, dayglo yellow just isn’t fashionable, not in any possible universe, and flashing lights are soooo middle-aged bike commuter. Maybe because I’m a dorky middle-aged bike-commuter, I just don’t care what I look like on a bike, as long as I’m visible. And maybe for the same reason, I think adding risk to your life for the sake of fashion statements is about as stupid as it gets.

Break out the Day-glo, the blinking lights, and the dorky helmets. We’ll all look dorky together, and we’ll all live to bike another day.

I thought just a little more analysis was warranted. (If you want to see what I’m talking about, look at yesterday’s post.)

Here are raw # counts based directly on charts in the report (pp. 43-44, for those who want to follow along – keep in mind that the City is working on a revision to correct math errors). I have combined a few items, because it seemed to make sense:

1. Top 6 bicyclist factors contributing to bike-car accidents

2. Top 6 driver factors contributing to bike-car accidents

A few things are worthy of note:

1. The top two factors involved in accidents are driver-related: dooring and failure to see cyclist. Together, these account for 353 of the 1091 accidents (32%) for which there are behavioral factors. Cyclists are a close second, though, with a combined 215 (running lights and stop signs, and salmoning) for the next two highest, for 20%.

2. Drivers account for 489 contributing behaviors, cyclists 392. I don’t think it’s worthwhile using this to find fault with drivers, but it’s equally clear that the report’s emphasis on cyclist faults was unwarranted. [If you're paying attention, you may have noticed more discrepancies. 489 plus 353 falls pretty far short of 1091. Where does the balance go? You're guess is as good as mine.]

3. Good news for cyclists: we can eliminate about 1/2 of our contribution to accidents by changing two key behaviors: stop salmoning, and stop running red lights.

4. More good news for cyclists: we can help eliminate a good number of driver causes as well, by

• leaving more distance between you and parked cars;
• not dodging to the right side of stopped taxis (taxis were disproportionately represented in dooring incidents, likely from passengers exiting);
• adding visibility: safety vests, bright colors, lights;
• riding predictably: pick a straight line and stick with it. (Weaving in and out of traffic was not listed as a contributing cause, but it is almost certainly a contributing cause to being invisible to drivers at critical moments.)

5. We need more detailed accident information. Many of these categories probably overlap. When a driver didn’t see a cyclist, was it because the cyclist was unlit and wearing black at night? Was it because the driver was more attentive to a cellphone? Was it because the intersection has poor sight lines?

6. The priorities of policy decisions initially based on the (flawed) initial report had to do with enforcement, especially of bikes running red lights. I hope Boston re-aligns priorities based on a better analysis of the data. For instance, the prevalence of dooring suggests a need for better bike lane design that accounts for the “door zone” adjacent to lines of parked cars. Likewise, if there are particular streets where salmoning (riding against traffic) is a major problem, it’s worth exploring whether a contraflow bike lane–a lane going the opposite direction of traffic on a one-way street–would add order that would reduce the number of collisions. In other words, as Boston re-examines the data, I hope they also re-examine it with a broader mind-set that includes not only directly addressing cyclist and driver behaviors with enforcement, but re-thinking the engineering of roads as well. Many of these behaviors could also be reduced with more sensible traffic patterns.

7. Speeding, really? I just can’t let it go. I cannot fathom how more cyclists than cars were described as “speeding” in accident reports. Here’s my best guess: the word “speeding” means different things for cars and bikes. For cars, it means exceeding posted speed limits. For bikes, it means exceeding speeds that caution might call for in certain circumstances. In other words, it’s a double standard. In a city where posted speed limits are often unsafe given the numbers of pedestrians and cyclists, what this data-point says to me: reduce the posted speed limits. How many of those driver-attributions of “didn’t see bike” really just mean that they didn’t see the bike in time to stop, but might have if they’d been going 25mph?

8. The other major finding in the report that comes as no surprise: a disproportionate number of cyclists involved in accidents are between the ages of 18 and 22. What about a concerted effort by the City and bike organizations and campus safety and security staff to educate students at MIT, Harvard, Northeastern, and BU (the big bike campuses) about bike safety? The major difficulty is the new influxes annually, learning high-risk behaviors from their hyper-hip predecessors. But a payoff with these populations would be huge.

On the face of it, it seemed like a bizarre claim: that bicyclists running red lights were responsible for close to 30% of bike accidents in Boston in the last 4 years. Yes, we keep hearing about the reckless, young urban cyclists who habitually run red lights… but 30%? But there it was in a full-color graph in the Globe reprinted from a City of Boston Report. Here’s the graph:

The thing is, it just ain’t so. Later in the report is a summary of the numbers from which those percentages were presumably drawn:

These numbers tell a rather different story from that graph: Note, first of all that, that dooring outnumbers bicyclists running red lights by more than a factor of 2, and that “Driver Did Not See Bicyclist” outnumbers “Bicyclist Ran Red Light” by nearly a factor of 2. So, a considerably more accurate picture emerges of proportions of accidents caused, in which drivers or passengers not seeing bicyclists (dooring is really a subset of not seeing a bicyclist) contributed to nearly 40% of accidents, while bicyclists running red lights accounted for only about 9.5%.

The Boston Magazine blog corrected its article late in the day on Thursday, May 16, owing to vocal complaints by Pete Stidman of the Boston Cyclists Union and Aaron Naparstek of MIT’s City Design and Development Group, who both caught the glaring math errors. The Boston Globe also ran a corrected graph in Thursday’s paper, but it’s behind a paywall, so I can’t share it.

You will see different %’s in the Boston Magazine blog: that writer calculated % based on all accidents; a helpful statistician named Matt pointed out in a Boston Cyclists Union Facebook post that you can’t put total accidents in the denominator if the numerator is limited to accidents with narrative labels attached – only about 1/2 (891) of the total.

And what in the world is up with that “Bicyclist Speeding” number? Twice “Driver Speeding?” Really? I don’t know about other cyclists, but when I really let loose on the flat, I top out at 30mph. Even in a 25mph zone, it’s hard to call that speeding.

Sometimes you can plan for it, sometimes you can’t. Sometimes a sickness in humanity causes the deaths of innocent people, and you stop and wonder what could have prevented it, and how you can go about your life the next day without dread, especially if the life of someone you know has been pushed off course.

But you go about the next day, and the next, and we all return eventually to whatever “normal” is for each of us. Most of us are good people. We outnumber the bad people 100:1, maybe 1000:1, or more. But most of the time, in our “normal” days, with mortality far away and annoyances and mundane tensions nearby, even if we’re kind of passively good, we forget to go out of our way to be good. On a normal day, I know I probably swear under my breath more often than I do a good turn.

There are a lot of really refreshing stories of heroism and goodness today that restore faith in humanity. As life returns to normal, hang onto those stories, and be good to each other. That’s ultimately what safety is all about: caring enough for the rest of humanity to go out of your way for them, even if it’s just a little out of your way, for a little thing.

Safety isn’t really about helmets and lanes and traffic signals and laws, though all that stuff is important. At it’s core, safety is a mindset. Another word for it is “care,” as in “take care.”

Take care.