Tuesday, December 31, 2013

The UC Study, "cyclist-only" accidents, and infrastructure

Michael Helquist hit a pothole on his bike

Mario Tanev's comment (below in italics) is a result of a recent exchange on Streetsblog, during which I questioned the cycling community's failure to even try to come to grips with the implications of the recent UC study on cycling accidents in San Francisco. The study found that between 2000 and 2009 the city significantly under-counted cycling accidents by relying on police reports and ignoring 1,205[later: that number should be 1,377] injury accidents to cyclists reported by San Francisco General Hospital, the primary trauma center in the city.

Your argument seems to be that because a lot of bicycle injuries are solo falls, infrastructure is not at fault. But then, the rate of injuries in countries with good bicycle infrastructure are much lower, solo falls or not, so something has to give.

No, that's not my argument. In fact I've said that infrastructure can be important in preventing cycling injuries, especially the condition of the surface of city streets. Potholes can result in repair bills for motorists, but for cyclists they can be the cause of serious injury. San Francisco's streets are famous for being poorly-maintained, and this is one issue I agree with the Bicycle Coalition about (I also objected to the city borrowing money to pay for routine street maintenance, especially since the city already makes so much money preying on city motorists---$170 million a year from parking meters, parking lots, and parking tickets---and brings in more than $80 million a year in sales taxes for transportation projects, money that's supposed to be for that purpose.)

I've also mentioned the problem rail tracks can pose for cyclists. 

I don't know about other countries, but I do know San Francisco, a major American city.

The UC study calls "solo falls" by cyclists "cyclist-only" accidents to distinguish them from "cyclist-versus-auto" accidents. The authors of the UC study were surprised by the number and the severity of solo fall accidents:

In this work, we also unroofed a previously underappreciated population of cyclist victims, those who are injured in the apparent absence of involvement with an automobile. Further work needs to be done to understand risks involved in these incidents and to characterize those who are most often involved. Possible issues may include crashes to avoid cars, tires caught in light rail tracks, swerving to avoid pedestrians, or avoidance of unforeseen road hazards.

This seems to assume that cyclist-only/solo-fall cycling accidents are an unrecognized phenomenon and that the "issues" causing such accidents are external "road hazards." But the city's annual Collision Report says that 50% of injury accidents to cyclists are caused by unsafe behavior by cyclists themselves (page 24).

Solo falls have long been recognized as common by cycling experts. Robert Hurst confirms the above in The Art of Cycling:

Collisions with motor vehicles are potentially more damaging but account for no more than about 15 percent of all cycling accidents. About half of car-bike accidents are instigated by cyclists who ride into traffic without looking, ride on the wrong side of the street, blow lights and stop signs, or otherwise ride in an unpredictable and lawless manner. This means that about half of car-bike collisions could be prevented if cyclists would simply follow traditional traffic-law principles. Most of the rest could likely be prevented with a little experience, preparedness, and respect for the perils of the road. Admitting it is the first step toward moving beyond it (page 161, emphasis added).

John Forester in Effective Cycling:


When you mention cycling accidents, most people assume that you mean car-bike collisions, because this is the only kind they worry about. This is wrong, because car-bike collisions account for only about 12% of cycling accidents (page 262).

Bert Hill says that only 18% of cycling accidents involve another vehicle.

The UC study found that solo falls are under-reported in San Francisco:

We found that police-generated bicycle injury data underreport injuries. Furthermore, this underreporting was much more pronounced for CO[cyclist-only] than for AVB[auto-versus-bicycle] injuries. Our data showed a higher proportion of matched data from the SFGH database compared with the SWITRS[police report] match ratio (45% vs. 31%). This suggests that there are fewer CO crashes in which the police are called and the victim went to the hospital.

What is also new and significant: the UC study found that solo falls can cause injuries just as serious as auto-versus-bicycle accidents:

Nineteen percent of AVB[auto-versus-bicycle] injuries and 53% of CO[cyclist-only] injuries required admission to the hospital intensive care unit. Based on SFGH data, we found that those with CO injuries were four times as likely to require intensive care unit admission...The median number of hospital days was 3 days for both admitted AVB and CO injury patients. The median Injury Severity Score for both AVB and CO injuries was 10, but a higher proportion of AVB victims died compared with CO victims (3.7% vs. 2.0%). This distribution however was not statistically significant. Among injuries for which we had hospital disposition data (39% of the total), there was no difference between those with AVB and CO injuries.

Some riders are forced to ride on the sidewalk due to fear of collision with cars, but sidewalk riding is more dangerous in other aspects, due to uneven pavement and obstacles.

"Obstacles" like those pesky pedestrians who clutter up city sidewalks? Except for children, riding a bike on sidewalks is illegal. When cyclists are afraid of riding on the street with cars, it's Reality sending them a message: riding a bike in San Francisco is dangerous. Don't do it.

San Francisco is a hilly city and hills make bicycles more difficult to control. That's why you shouldn't try to direct bicyclists to ride on hills, which you've personally been doing when opposing the Fell/Oak project.


The Fell/Oak bike project was completely unnecessary, since there was an easily available alternative on nearby Page and Hayes Streets. The only serious hill on either of those streets is between Divisadero and Broderick on Page Street.

The real question is how many bicycle solo falls are on a separated cycle track, like the panhandle. No report has looked specifically at solo injuries in cycletracks, but reports have shown an across the board reduction in injuries. Thus, you cannot make the conclusion you make. 

There are few streets in San Francisco that have enough space to make "a separated cycle track." The one planned for Masonic Avenue is no exception, since that bike project will eliminate 167 parking spaces between Fell and Geary to make separated bike tracks. That means the city will no longer be able to use those parking lanes to make extra traffic lanes during the morning/afternoon commute, which means that project will jam up traffic for the more than 44,000 people who now use Masonic every day. And that will be done on behalf of a completely unknown number of future cyclists. That is, there's no fact-based study showing that the number of future cyclists will be anywhere near enough to justify this project. 

You and your bike friends are a very small minority in San Francisco---only 3.4% of all daily trips in the city are made by bicycle---which makes it impossible to justify redesigning city streets against the interests of 95.6% of those who now use our streets. But City Hall is going to do it anyway because...? 

The UC study shows that riding a bike in San Francisco is even more dangerous than anyone thought, infrastructure or no infrastructure. 

And the city and the Bicycle Coalition are encouraging even children to engage in this dangerous transportation "mode." When I wrote about this shocking bit of irresponsibility a few years ago (Children and the bike cult), it got more comments than any previous post, mostly from bike dudes trying to justify the unjustifiable. 

Here's what cycling expert Robert Hurst says about that:

While [John]Forester claimed that even children could ride safely on busy streets using the vehicular-cycling principle, our way is unquestionably for adults…The streets demand from us an awareness and maturity that would be very rare in a child (The Art of Cycling, page 66).



Rob,

Your argument seems to be that because a lot of bicycle injuries are solo falls, infrastructure is not at fault. But then, the rate of injuries in countries with good bicycle infrastructure are much lower, solo falls or not, so something has to give.

Infrastructure ABSOLUTELY has a lot to do with solo falls as well:

1. Train tracks with wide gaps and lack of proper markings. Competition with cars driving fast forces riders to merge through tracks in a fast and unsafe manner. 

2. Riding in gutter is more dangerous due to uneven/slanted surface, debris 

3. Riding next to parked cars (due to pressure from motorists) could result in hitting a mirror. It is also unclear if impact with open doors is counted as solo falls or not. 

4. Some riders are forced to ride on the sidewalk due to fear of collision with cars, but sidewalk riding is more dangerous in other aspects, due to uneven pavement and obstacles.

5. Many riders choose to ride too fast in order to keep pace with automobiles in order to avoid harassment. 

6. Many of riders ride light racing bicycles in strained positions in order to attain higher speed (to avoid harassment), but those bicycles are harder to control. 

7. Single-phase left turns are dangerous since the person needs to extend their left hand to signal, thus reduce control of their bicycle. It is doubly dangerous if they also have to cross tracks at the same time. Implementation of a two-phase left turn would reduce this hazard. 

8. Motorists don't realize the consequences of their actions lead hazards for bicyclists. A swerve in front of a bicycle even without the bicycle and car colliding can result in the bicyclist losing control. 

9. Traffic lights timed for cars mean that bicyclists race to get through them or risk stopping at every corner. 

10. San Francisco is a hilly city and hills make bicycles more difficult to control. That's why you shouldn't try to direct bicyclists to ride on hills, which you've personally been doing when opposing the Fell/Oak project. Lack of infrastructure on the flat streets increases the volume of bicyclists trying for the hills. 

11. Lack of infrastructure leads to fewer people bicycling, which leads to the sense of being alone. When there are no bicyclists around cyclists tend to make more unsafe maneuvers because there is no example and no peer pressure. Just like cars drive more slowly in a nice neighborhood with trees, bicycles ride more slowly when there is a relaxed vibe. 

12. Conversely, narrow bicycle lanes cause those who need to pass to go too fast, and into traffic, which then brings up some other issues already mentioned. 

The real question is how many bicycle solo falls are on a separated cycle track, like the panhandle. No report has looked specifically at solo injuries in cycletracks, but reports have shown an across the board reduction in injuries. Thus, you cannot make the conclusion you make.


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6 Comments:

At 9:58 PM, Blogger Mark Kaepplein said...

There needs to be a clear distinction between urban CO crash situations and general cycling. Nation-wide, cycling is generally recreational including Moto-X and downhill cycling in which about 100% are CO accidents. Hence this is why CO accidents are 85% on general for cycling, while drop to 50% in urban environments. A safety theory inflicted on motorists is a misnomer called "traffic calming". Perhaps that is what cyclists need to reduce CO, BVP (bike vs. pedestrian) and AVB accidents.

 
At 8:19 AM, Anonymous Gregski said...

Rob, this Streetsblog commenter has blessed us with a treasury of material here, much of it illustrative of the unaccountable, immature mid-set of many of my fellow city cyclists.

Items 4,5,6,9,10 and 12 all refer to choices and tactics that are completely under the control of cyclists regardless of external circumstances ("cyclists race to get through [timed lights]") or to the inherent qualities of cycling and bicycles ("light racing bicycles...harder to control"). I'm stipulating here that all the writer's statements are accurate and valid, which they are not.

Items 7 and 11 also describe inherent qualities, although the writer fallaciously blames infrastructure. Law-abiding, considerate cyclists must ride one-handed when signalling their left AND RIGHT turns regardless of street signals. And the choice to make "unsafe maneuvers" has nothing to do with infrastructure, "peer pressure" or lack of "examples" although I can understand how a juvenile mind could fail to appreciate this.

Let's give the writer credit for item 8 which is insightful and merits our curiosity.

The almost constant subtext here is that cyclists' behavior, including speed and unsafe maneuvers is usually somehow coerced by the road configuration as opposed to, say, the cyclists' impatience or their egotistical delusions of invulnerability and immortality.

If "the rate of injuries in countries with good bicycle infrastructure are[sic] much lower, solo falls or not" let's please consider the hypothesis that the reason for this might be the cyclists in those countries base their traffic behavior on different values than many San Francisco cyclists do. They might, for instance, give higher value to their responsibilities than they do to their perceived "rights". They might value their own and others' safety and well-being above their own convenience.

It wouldn't surprise me in the least to see Dutch or Danish cyclists, if they and their bicycles were to be transplanted here into our wretched streetscape, sustain fewer injuries than native San Francisco cyclists.

 
At 7:08 PM, Blogger Mario said...

It's quite laughable that people discount the incentives created by the infrastructure when it comes to bicyclists. Somehow you think a standard should be set on bicyclists to be perfect people and always follow the rules, even if it makes them feel (and likely be) in more danger when they do so. Yet, you don't think that standard should apply to motorists. In fact the law in California states that the speed limit on a street is to be set to the 85 percentile of how people actually drive, regardless the actual speed limit. Ergo, if most people speed, the limit goes up. Human behavior is very much guided by our environment, but the environment is very forgiving to motorists, and very unforgiving to bicyclists. Those who refuse to acknowledge the impact of the environment on our behavior just cling to their own biases.

 
At 8:25 AM, Anonymous Gregski said...

Be careful whenever you light up a joint, Mario. With all the straw men you build you're in danger of burning down your whole house.

 
At 10:45 PM, Blogger Mark Kaepplein said...

Mario, most people do acknowledge the impact environment has on behavior by choosing the much greater safety of cars over how unforgiving impacts are when riding a motorcycle or bicycle.

 
At 10:20 AM, Blogger Rob Anderson said...

"Human behavior is very much guided by our environment, but the environment is very forgiving to motorists, and very unforgiving to bicyclists. Those who refuse to acknowledge the impact of the environment on our behavior just cling to their own biases."

The environment made me do it! This blanket rationalization justifies a lot of dumb, dangerous behavior by city cyclists, like those listed in the last Collision Report on page 24, including running red lights and stop signs, riding the wrong way on one-way streets, failure to yield, unsafe lane change, etc.

Nor does it really address what the UC study found about the under-reported "cyclist-only" accidents that are more numerous and just as severe as "cyclist-versus-auto" accidents.

 

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