Bicycle Austin forum

MichaelBluejay

Webmaster

From: Austin, TX

Registered: 2008-05-26

Posts: 1,455

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Study shows that dedicated bike lanes cut injuries in half

Bike lanes cut the risk of injury by 50%, separated bike lanes cut it by 90%.

I wonder what the Effective Cycling crowd will have to say about this one.

http://www.theatlanticcities.com/commut … half/3654/

Jack

Member

Registered: 2013-03-27

Posts: 344

Re: Study shows that dedicated bike lanes cut injuries in half

That would be this:  http://www.johnforester.com/Articles/Fa … juries.pdf  Evaluate for yourself.

"In the much more impressive cycle-track issue, the authors proclaimed enormous crash reduction without informing the readers of the two relevant facts. First, that their data came from only one installation. Second, that that installation was not along a typical city street but in the only situation in which a plain cycle track could possibly be safe, a place without crossing or turning movements by motorists, cyclists, or pedestrians. The authors refer to the forty-year-old cycle-track controversy as if they had studied it, but clearly they don’t understand it. It is clear that the authors have such faith in the cycle-track concept that its astonishing data failed to alert them to investigate why such data was reported.
The authors’ failure to understand the difficulties of cycle tracks and the only conditions in which cycle tracks may be safe constitute traffic-engineering incompetence.
The authors’ proclamation of the great safety of cycle tracks and their failure to be alerted to problems with the source of their cycle-track data demonstrate the improper influence of ideological considerations."

Note also that the authors credit "bike lanes" with the effect not of the stripe but of the lack of parked cars.

Last edited by Jack (2013-11-04 16:57:54)

bizikletari

Member

Registered: 2009-03-18

Posts: 223

Re: Study shows that dedicated bike lanes cut injuries in half

Thanks to the father of vehicular cycling, Palo Alto didn't follow the Dutch path; and with that we should say: Oops —40 years later.

Jack

Member

Registered: 2013-03-27

Posts: 344

Re: Study shows that dedicated bike lanes cut injuries in half

And more interesting data on topic:   http://janheine.wordpress.com/2013/05/2 … -together/

bizikletari

Member

Registered: 2009-03-18

Posts: 223

Re: Study shows that dedicated bike lanes cut injuries in half

And more interesting data on topic:   http://janheine.wordpress.com/2013/05/2 … -together/

Excelent article, but it made me sad whe I read Bike Boulevard.

On the bright side, Austin officials are trying to obtain for the city --at least-- a Gold ranking from the League of American Wheelsmen.

Jack

Member

Registered: 2013-03-27

Posts: 344

Re: Study shows that dedicated bike lanes cut injuries in half

On the bright side, Austin officials are trying to obtain for the city --at least-- a Gold ranking from the League of American Wheelsmen.

More on the L.A.B. (not wheelmen for decades now) program:  http://limeport.org/category/facility-design/    http://www.labreform.org/BFC.html 

. . . and a healthy alternative approach:    http://www.ohiobike.org/obf-cfc.html

Jack

Member

Registered: 2013-03-27

Posts: 344

Re: Study shows that dedicated bike lanes cut injuries in half

More on why the study's conclusion is faulty:  From the article "The genius of this study is that each biker was used as his her own control. On a map, the researchers traced each route with the riders and identified where their accidents had occurred. A random sampling of other points on those same routes was used to compare with the injury locations. That means that the final results weren’t skewed by the fact that some bikers were male or young or drunk, or that the weather was bad some days, or that some bikes themselves were wonky. The researchers then visited all of these locations – about 2,100 of them – to classify them among the 14 route types. And the final statistical analysis confirmed that, indeed, accidents happen when we don’t build (or paint) cyclists their own infrastructure."

For why the method is wrong and leads to wrong conclusions, see:  (1) criticizing the methodology directly, http://john-s-allen.com/blog/?page_id=5702   (2) more generally, http://john-s-allen.com/reports/montreal-kary.htm (particularly note, if nothing else "methods that conflict with the authors’ own results published elsewhere" in part 4. and "Injury" in part 4.2 and part 5.3 showing why their statistical analysis is faulty and part 6 for why the representation made of the statistical results was incorrect or misleading). 

They do not even try to account for why their study contradicts the large body of literature on the subject, which often is a good sign you are looking at junk science.  'The authors provide a detailed criticism of a single study from 1994 that came to a conclusion opposed to theirs. They refer to a recent study of bicycle paths in Copenhagen[[15]]  — much larger, more comprehensive and detailed than theirs, that used a study design superior to their own and that also came to opposing conclusions — only with the remark “conflicting studies with warnings of increased crash rates”.  They omit all reference to the body of other literature, including further studies using methods superior to their own (e.g. before and after in combination with comparison streets), that also came to opposing conclusions. Overviews and examples of this literature can be found  elsewhere [[16]] [[17]].'