Monday, May 05, 2014

Twitter, ADD, and that UC study

Photo, Centers for Disease Control

Maybe it's because of a Twitter-based intellectual degeneration, but I get some remarkably stupid comments on that important UC study of the city's radically flawed method of counting cycling accidents. A good recent example:

Regarding the UC study - How about you get someone who isn't freaked out by bicycles to explain what the study might mean? All it tells me is that people (not specific on age, what they were doing) can get hurt biking, like they can with all kinds of other activities. Do you honestly believe that people think biking is absolutely safe?

That I'm "freaked out by bikes" or anti-bike has been a routine charge by the remedial readers in the bike movement. Actually, I became interested in the issue when City Hall was rushing its 500-page Bicycle Plan through the process without any environmental review that was clearly required by the California Environmental Quality Act (CEQA). 

I also noted that bike advocates were consistently downplaying the dangers in riding bikes to encourage more people---even children---to ride bikes in San Francisco. 

This is an important public policy issue, since the Bicycle Plan is taking away dozens of traffic lanes and thousands of parking spaces from busy city streets to make bike lanes for a small minority of cyclists (After years of pro-bike, anti-car propaganda from City Hall and the Bicycle Coalition, only 3.4% of all trips in the city are by bicycle).

A short recap for those---there are so many!---with attention deficit disorder who can't focus long enough to read even short documents: San Francisco has long relied on police reports to count injury accidents. Based largely on those police reports, every year the MTA publishes a count of vehicle, pedestrian, and cycling accidents in its Collisions Report (see page 3 for the count methodology).

The UC study was done by University of California doctors. The New York Times did a story (How Safe Is Cycling? It’s Hard to Sayin October, 2013 that referred to the study:

Dr. Rochelle Dicker, a trauma surgeon at the University of California, San Francisco, does not see it that way. She cares for victims of the worst bicycle injuries, people who might need surgery and often end up in intensive care. So she decided to investigate those crashes. She and her colleagues reviewed hospital and police records for 2,504 bicyclists who had been treated at San Francisco General Hospital. 

She expected that most of these serious injuries would involve cars; to her surprise, nearly half did not. She suspects that many cyclists with severe injuries were swerving to avoid a pedestrian or got their bike wheels caught in light-rail tracks, for example. Cyclists wounded in crashes that did not involve a car were more than four times as likely to be hurt so badly that they were admitted to the hospital. Yet these injuries often did not result in police reports---a frequent source of injury data---and appeared only in the hospital trauma registry. Dr. Dicker is not a cyclist, but she said, “Lots of my colleagues do not want to ride after seeing these injuries.”

Half of 2,504 would be 1,252 cycling accidents not counted by the city between 2000 and 2009, the period covered by the study.

From the abstract of the UC study:

Police reports are the industry standard for assessing transportation-related collisions and informing policies and interventions that address the issue. Previous studies have suggested that police reports miss a substantial portion of bicycle crashes not involving motor vehicles. No study to date has explored the health and economic impact of cyclist-only (CO) injuries for adults in the United States. Our objective was to use trauma registry data to investigate possible under-representation of certain cyclist injuries and characterize cost...

Of all bicycle-related injuries at SFGH[San Francisco General Hospital], 41.5% were CO[cyclist-only] injuries and 58.5% were AVB[auto-versus-bicycle] injuries. Those with CO injuries were more than four times as likely to be required of hospital admission compared with those with AVB injuries...From 2000 to 2009, 54.5% of bicycle injuries treated at SFGH were not associated with a police report, revealing that bicycle crashes and injuries are under-recognized in San Francisco.

Since the text of the study is behind a paywall, I transcribed it here.

Neither the Chronicle, the Examiner, nor either of the city's weeklies have even mentioned the study yet. This is apparently because its findings undermine the groupthink acceptance by the local media of City Hall's anti-car, pro-bike policies that are now redesigning city streets on behalf of a small special interest group against the interests of more than 95% of those who now use city streets, including Muni passengers.

I'm hardly the only one to notice the dangers of riding a bike in San Francisco---or anywhere, for that matter. From the Centers for Disease Control and Prevention [Later: the CDC has removed from this link both the picture above and the paragraph below. I asked them for an explanation some time ago but they didn't respond]:

While only 1% of all trips taken in the U.S. are by bicycle, bicyclists face a higher risk of crash-related injury and deaths than occupants of motor vehicles do. In 2010 in the U.S., almost 800 bicyclists were killed and there were an estimated 515,000 emergency department visits due to bicycle-related injuries. Data from 2005 show fatal and non-fatal crash-related injuries to bicyclists resulted in lifetime medical costs and productivity losses of $5 billion.

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At 8:16 PM, Anonymous Anonymous said...

I must admit, I have broken bones twice in my lifetime, and BOTH times it was on a bicycle and both times NO automobile involved.

One time I was on the dirt path at Crissy Field and I hit a small bump I was not expecting and lost my balance, fell and broke my arm and wrist, and the other time was the Marina Green bike path where a distracted bike rider coming the other way ran into me, I fell and broke some ribs.

At 10:11 AM, Blogger Rob Anderson said...

The solo fall issue---most cycling accidents don't involve another vehicle---is a major reason why riding a bike can never really be made safe.

City Hall and the Bicycle Coalition are irresponsibly overselling cycling, leaving would-be cyclists with the impression that riding a bike is simply a cool, safe, green, win-win deal for everyone. The push to encourage children to ride bikes in the city is particularly irresponsible.

At 11:35 AM, Anonymous sfthen said...

The New York Times ran article entitled, "Bicycle Riding: Our Most Dangerous Sport" by Edward R. Walsh (director of recreation for Westbury, L.I.) which stated "bicycling is becoming a runaway pacesetter for injuries and deaths... the National Injury Information House classifies it as our most dangerous sport, nearly three times as hazardous as football. The dangers will increase with biking's growing popularity."

Walsh notes lack of community committment to education, inspection and registration and lack of police enforcement with "cyclists practically immune from justice," as being in part responsible.

The author's L.I. community has six months of a SF Sunday Streets equivalent in which the Bronx River Parkway "is closed to vehicular traffic from 10a.m. to 2p.m." so you'd figure the SFMTA/ SFBC/ SPUR types would be crowing about this wonderful green sustainable bit of bicycle paradise.

So why no mention? Probably because the article was published May 21, 1978 !

And 35 years later bicycling is still our most dangerous sport.

At 2:40 PM, Anonymous James said...

And in your usual fashion, rather than address the questions I posed in my comment, you went on another biased tirade. My point was we don't know who these people were and what they doing (long distance, commute, racing) that caused a crash. Do the same people who get into these crashes exhibit other kinds of risky behaviors in other things they do? As in, people who are likely to get hurt in a car are as likely to be hurt bicycling or walking? You're asserting that the mode of transportation is the culprit, and not the individual.

Also, out of those crashes how many were serious and how many were just to make sure someone was ok? I've been in car accidents where I go to the emergency room to ensure that I'm ok and nothing is broken. When I asked for someone who is an expert, I would like to know if less than one non-fatal crash a day out of at least 24,000 people in San Francisco something to raise an eyebrow about? You're clearly not equipped to answer those questions given the fact that your failure to stop the bike plan from happening in SF gets in the way of your judgement.

Again, your suggestion that no one sees biking as risky is bullshit. No one anywhere is suggesting that riding a bike is intrinsically safe, though there are plenty of places in the world where it is successful and a hell of a lot safer. I could make the same safety argument for cars and say the DMV hides crash statistics and doesn't even mention crash statistics when talking about driving a car. Never did I once know about that when I got behind the wheel of a car. Is this some kind of mass cover-up to give the impression that driving a car is safe? At least the bike coalition has safety tips on their site. Can you find crash and death statistics on the clearly identified on AAA site? My point is there's an acknowledgment of risks with everything.

It's no the data I can't understand. It's your logic and motivation.

And by the way - Your claim that cycling is some kind of San Francisco progressive anomaly is bullshit too. Even Salt Lake City of all places promotes biking. They list safety tips and explain the risks of biking on the page.

At 10:17 AM, Blogger Rob Anderson said...

The only thing that you've clarified with this comment is that you have some kind of reading disorder.

The UC study has nothing to do with determining the responsibility for these injuries. It has two significant findings: that the city is failing to count a lot of cycling injury accidents, and that "cyclist-only" injury accidents are both the most under-counted and are just as serious as "auto-versus-bicyclist" accidents.

The city has been under-counting these accidents because it's been relying on police reports and ignoring many accidents treated at SF General Hospital, the primary trauma care center in the city.

Yes, the study is talking about serious accidents. From the study:
"In an analysis of the medical and social consequences of bicycle injury, it was shown that hospitalized bicyclists experienced issues including persistent disability, cognitive and behavioral changes, and permanent work disability."

Since there have been a lot more serious cycling accidents in SF than the city has been reporting, evidently riding a bike is more dangerous than the Bicycle Coalition and City Hall have been telling us.

I've never written anything like "no one sees biking as risky." What I'm saying is that City Hall is encouraging people---even children---to take up cycling without warning them about the potential risks, while implying that the dangers are all about infrastructure, that if the city just builds enough bike lanes the risks can be significantly mitigated.

Typical that you try to change the subject to car safety. By the way, as I've pointed out, if the city has been radically under-counting cycling accidents, is it also under-counting pedestrian and auto accidents? If the city has failed to count serious cycling accidents treated at SF General, is it also failing to count other accidents? Exactly how safe/unsafe are city streets?

City Hall likes the idea of getting people on bikes, since it sees that as a cheap way to mitigate city traffic congestion.

Nor have I ever written anything like "cycling is some kind of San Francisco progressive anomaly." Of course cycling is now fashionable in many parts of the country. But it's also clear that other cities are having the same problems accommodating the bike fad as SF is having: see this and this.

At 10:04 AM, Blogger Rob Anderson said...

Later (April 21, 2016): Note that the Centers for Disease Control no longer has the paragraph I quoted in the post when you click on that link, probably due to pressure from the bike lobby.


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