Safety study - checking their work

[Scott Mace]

I'm trying to check the work of this often-quoted study that seems to
conclude that more bicyclists on more segregated facilities equals safer
bicycling for all cyclists in a city.

https://batwgblog.com/2020/07/08/vtas-subway-extension-goes-off-the-rails/#more-2738

Has anyone on this list analyzed this particular study?

Scott Mace

[Frank Lehnerz]

Paul Schimeck wrote to the authors of that study. 

[Scott Mace]

Oops, I inserted the WRONG link.

Here's the study:

https://www.sciencedirect.com/science/article/pii/S2667091724000013

Scott

[William Sellin]

Seems anecdotal and finding what was expected, not a tested hypothesis

 - the addition of new cones in the road - and even new buffered bike lanes - would cause motorists to pay more attention and thus slow down - 

No scientific control of having other paint or cones or lane narrowing that were NOT specifically bike lane related...

Also - “Study" took lane width from travel lanes - California is tending to take buffers from the bike lane width so reduction in travel lane width occurs.

Bill Sellin 
714.943.3678
WASe...@gmail.com

Infrastructure Review Committee

      OCBike.org

Area Liaison to Caltrans District 12

      CABOBike.org

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[Mike Lasché]

Dear Scott,

I have not taken the time to analyze this study.   But, their bias seems clear, in their text, where they state that separated bike lanes are a proven safety measure.     I refer you to the literature review of the 2019 IIHS study on “protected bike lanes” which makes it clear that such proof is not available.   Nevertheless, PBL advocates blithely mouth the mantra that PBLs are proven safe.

I also refer you to the Trafitek Study of 2007, based on 26 years of separated bicycle facilities in Copenhagen, which showed that separated bike lanes led to statistically insignificant decreases in bike crashes between intersections.   But  separated lanes led to significant increases in motor vehicle, pedestrian, and bicycle crashes everywhere else.   Separated lanes also led to a whopping 1500% increase in mass-transit related crashes.

The mass transit crashes are interesting.   Though the author, Jensen, did not go into it, here is my take.   Without a separated lane, mass-transit users wait upon the sidewalk for buses, out of the way of all bike traffic except sidewalk cyclists.   With a separated lane, mass transit users either have to wait in the separated lane, or in the street, both not very safe.   Or, should the mass transit user wait on the sidewalk, now they have to cross a separated lane to board the bus.

If you would like to check out this study, which is the most authoritative study of separated lanes available, the link is;   https://www.researchgate.net/publication/237524182_Bicycle_Tracks_and_Lanes_a_Before-After_Study

Cheers,

Mike Lasche

Florida Walks and Bikes