Tuesday, August 25, 2009

Scofflaw motorists

While there is a public perception that cyclists are usually the cause of accidents between cars and bikes, an analysis of Toronto police collision reports shows otherwise: The most common type of crash in this study involved a motorist entering an intersection and either failing to stop properly or proceeding before it was safe to do so. The second most common crash type involved a motorist overtaking unsafely. The third involved a motorist opening a door onto an oncoming cyclist. The study concluded that cyclists are the cause of less than 10 per cent of bike-car accidents in this study.
From University of Toronto Research, via How We Drive.

I wasn't going to post this Pearl Izumi road rage video (I can co-exist with cars on the road), but since there is misinformed animosity from some motorists, it kind of fits.


  1. Fritz, be very cautious about that 10% figure. I have a copy of the Toronto car/bike collision paper that Dr. C referenced. It will be a day or two until I've read and analyzed it. The cars-are-evil crowd is blissfully accepting this as gospel.

    Where's my red pencil?

  2. Wirehead, don't confuse "blame" and "cause".

    In the article you linked to, the writer suggests that cyclists were blamed twice as often as motorists. But, that doesn't say ANYTHING about the actual cause of the collision...could be bias on the part of the LFO writing the report.

  3. @Wirehead, that's not a study, that's an "analysis by the Chronicle" and there was a lot of discussion on Bay Area bike lists about that analysis. It begins with data from law enforcement that Bob Mionske and others believe is biased.

    I don't know about that 10% figure either, but I think the truth is probably somewhere in between.

    Recounting some of my own experiences with car collisions:

    1. Driver ran a stop sign without slowing at all and plowed into me. Bystanders and the responding police officer all blamed me for the crash, telling me I should pay more attention, although I had clear right of way at the intersection.

    2. I'm doing the speed limit on Willow Road Menlo Park when a motorist hooks me, sending me flying over the handlebars and over her car (I landed on my feet). The motorist jumps out of her car and tells me I shouldn't be going so fast and blames me for the 'accident', although she's the one driving recklessly. I didn't even bother calling the police on that one. The big dent on her trunk made it even in my book.

  4. I should add there are numerous instances of bike crashes where I was at fault, but there's only one that actually involved a car (I followed too closely and rear ended him). The others are things like wiping out while taking a turn at high speed.

    Oh, there was the time I got annoyed at some loose bar tape flapping in the wind, so I yanked at the bar tape, which made my handlebar flip around. While I was moving. In a fast paceline. That one didn't end too well.

  5. Cautious my bum. Drivers cause all collisions in my book. If you have power brakes and you can't avoid a collision with a cyclist, it's your fault.


  6. Here's a link to the full report. So far, it appears that a large number of collisions involve sidewalk cyclists (30%), but as yet I can't determine if they were on sidewalks or in crosswalks. Regardless, in Toronto, sidewalk cycling is illegal which would automatically make the cyclist at fault. Now, if that's the case, there's no way that cyclists could be responsible for only 10% of collisions.


    A quick tally of collision type table shows motorists initiated (not caused) nearly 70% of the crashes. 'Initiated' may not be the best description, but I've been skimming. Again, it doesn't jibe with the 90/10 figure.

    I recall reading another study that showed a 55/45 split, if I recall right, and given normal human behavior, I'd have greater confidence in those figures.

    Here's that study. Oh, joy. More stuff to read.

  7. I couldn't find the actual 10% study ... The link above goes to a 2003 report. Doubt that's what he's referencing. Anybody got the current study?

  8. I think the problem is the same one as motorcycling.

    You can give two numbers. One is for the entire population, including squids (that being slang for a motorcyclist who has neither safety gear nor understanding of how to ride safely) and the other is for the population excluding squids and other idiots.

    Even the "study" from the Chron, if you exclude salmon (wrong way cyclists) and other idiots, it doesn't look so bad. If you were to tell me that it's only the cyclists fault 10% of the time for cyclists who ride safely in the correct direction, with lights on at night, and without running lights, that wouldn't surprise me in the slightest.

  9. ...if & i emphasize "if", the numbers are actually going to influence how we, as cyclists are to be perceived by the judiciary & law enforcement agencies, great, otherwise it all seems moot...

    ...ya gotta cover your own ass out there...laws won't stop drivers not paying attention or w/ negative attitudes towards cyclists...

    ...cynical ???...you betcha...& why would that be ???...

    ...for every new law, for every well designed piece of infrastructure intended to facilitate safer cycling, for every step forward our collective culture takes, i still find a regular & overwhelming imbalance...

    ...that includes more drivers who seem to believe we're nothing more than a subspecies playing on children's toys...

    ...& that attitude is facilitated by the aforementioned judiciary & police agencies through their enforcement & sentencing policies...

    ...if i sound the naysayer, so be it...kill a person w/ a gun, do some real time...kill a cyclist w/ a car because you "just weren't willing to pay attention behind the wheel" & generally you'll get a "wrist slapping" at worst...

    ...ok...enough ranting...

  10. Too true bgw. The main value of these stats (if "accepted") is in hopefully changing the attitudes of those in law enforcement. As one prosecutor friend explains "swim with sharks, die by sharks".

  11. The video could be saying something about the market presence of cyclists. Now, perhaps it's still such a small, freakish group that that's a small, freakish expression of a far-out group. Or not.
    I wonder how much suppressed car-hate there really is out there. So, for instance, if somebody figured out how to simply desensitize traffic signals so that it took somebody tripping the pedestrian walk to get 'em to change, would there be a rash of 'em?

  12. @BGW - Good point -- inattention by anybody at any time is why defensive driving and defensive cycling are so important. As a cyclist, we're much less able to quickly swerve away when the guy in the next lane over spaces out, so we need to be doubly vigilant.

    @Jack - I agree that law enforcement need to more awareness on the traffic situations that impact cyclists.

    @Sioux - and now you have my mind running a million miles an hour thinking how to make that happen. Oh boy. The problem, of course, is any problem at any busy intersection will be very quickly fixed.

    @Ed - I'm looking forward to your red lined copy of that paper. :-)

  13. The university website offered this update:

    CORRECTION–August 26, 2009:

    Dr. Chris Cavacuiti has informed us that his interview contains a factual error.

    In the interview, Dr. Cavacuiti is quoted as saying “The [Toronto Collision] study concluded that cyclists are the cause of less than 10 per cent of bike-car accidents”. Dr. Cavacuiti has asked us to make readers aware that the Toronto Collision study was actually designed to look at the cause of bicycle/motorist collisions but not culpability.

    It is actually several studies conducted by the Charles Komanoff and member of the Right of Way organization in New York that concluded that concluded that cyclists were strictly culpable for less than 10 per cent of bike-car accidents.

    Dr. Cavacuiti would like to apologize for any confusion this error may have caused.


    Now, I think the study Cr. C. refers to is here:


    Click on research/Killed by Automobile. That's the one I'll be reading tomorrow. But with an org named 'Cars Suck' just how much objectivity should we expect? I skimmed some of it, and let's just say the language is inflammatory, obviously slanted, and more on the order of unabashed partisanship rather than true analysis. If you hate and fear cars, this one's for you!