Re: [Ebbc-Talk] [Discuss] Portland finding green "bike boxes" at intersections INCREASE right-hook collisions

John,

My original post was an attempt to discuss the nuances of traffic design. I am sorry that you apparently misread and/or misunderstood my words.

Several of my fellow LAB League Cycling Instructors nationwide who are also trained traffic engineers and traffic planners have identified precisely the design weakness you cite in your email as the primary problem with these "green box" traffic signal treatments:

> The letter identifies that the likely issue is the fact that the high crash incidence sites are all in the downhill direction and involve cyclists traveling at relatively high-speeds and overtaking right-turning vehicles. (from JKW's email below)


The above--a significant problem--was precisely my reason for posting the link and email that I did, which did not "assign judgment" as you claim.

I stand by the assessment of the above LCIs , which I share, that the addition of the green "bike boxes" to these particular signalized intersections "may have actually increased the number of cars hitting cyclists who are moving up on the right in curbside bike lanes during the green phase." (Please note the conditional verb tense.) 

This very real problem with the green "safe zones" comes from cyclists who (falsely) believe--simply because the green paint is installed on the pavement--that they can engage in the dangerous practice of moving up on the right (blind) side of turning cars while in adjacent bike lanes. (This illusion of greater safety exists just as much on flat terrain as on downhill- or uphill-facing intersections. Only the speeds change.)

The current safest "best practice" in the LAB safety classes that I occasionally teach as a League Cycling Instructor (LCI) is for cyclists to "take the lane" and ride through intersections like these as a vehicle, positioned in the center of the through traffic lane. This is MUCH safer than riding through intersections in any bike lane--in the blind spot of right-turning vehicles. This is true regardless of whether green-painted safe zones are present or not, but the risk increases with the green paint because cyclists falsely assume they are safer. 

In the Portland situation, it is arguable (although not proven yet) that the green "safe zones" themselves are a contributing factor to the increase 
in the accident rates cited in the study at these four intersections, and it is more than worth pursuing in order to establish what degree of causality is involved from all possible factors. And I never suggested that green-painted safety zones should not be used where they will work.

The problem with designing bike-specific facilities like these green "safe boxes" and cycle tracks is that they are exceptions to the standardized principles and "rules of the road" that underly the Uniform Vehicle Code. By introducing nonstandard exceptions they add confusion to the overall traffic flow while simultaneously creating the illusion--but only the illusion--of added safety for cyclists. 
(Paint alone can never stop a swerving or turning vehicle from colliding with a cyclist.)

We run very real risks when we adopt increasingly nonstandard traffic designs and bike facilities in search of the illusory "holy grail"
of perfectly risk-free cycling environments. 

Regards,

Jon Spangler
League Cycling instructor #3175


On Oct 19, 2012, at 12:12 PM, John Knox White wrote:

> That's not what the article says. It says that number of crashes have gone up but that it is unknown as to why and that there a number of possible factors, including the possibility that it's the increase in the number of cyclists using those intersections, that have affected the crash-rate.
> 
> Be careful not to assign causation to your bias (everyone has one, not assigning judgement).
> 
> The DOT letter shows that 87% of the crashes occured at four (out of 11) intersections, suggesting that it was not the bike-box causing the problem, but other factors that may be exacerbated. 
> 
> In fact the letter states that "the bike box treatments appear to be serving their primary function, which is to mitigate the occurence of right-hook crashes at the start of the green-signal phase."
> 
> The letter identifies that the likely issue is the fact that the high crash incidence sites are all in hte downhill direction and involve cyclists traveling at relatively high-speeds and overtaking right-turning vehicles.
> 
> It also says that the treatment correlates with an overall decrease in crashes at 7 out of 11 locations. So the lesson at this point isn't "Bike boxes are bad, cyclists should just merge into traffic" It's ensure that this use is located in areas which are flat which is everywhere in alameda.
> 
> In fact, portland is not removing these treatments in the four problem areas, they are taking these lessons and adjusting their treatment to ensure the safety of users. the Local, and highly respected BTA advocacy organization is also standing behind them.
> 
> John Knox White
> 
> 
> 
> On Wed, Oct 17, 2012 at 4:39 PM, Jon Spangler <[email protected]> wrote:
> The "safe zones" established in Portland to protect cyclists from "right-hook" turns during green lights may have actually INCREASED th number of cars hitting cyclists who are moving up on the right in curbside bike lanes during the green phase:
>  
> http://blogtown.portlandmercury.com/BlogtownPDX/archives/2012/10/16/city-finds-bike-boxes-may-actually-increase-crashes
> 
> Although there are mitigating factors that cloud the doubling in car-bike collisions (an overall increase of 57% in bikes on the road over the past four years and a lock of clear causality attributable to the green "bike boxes" at intersections) it does appear that the number of collisions between moving cars and moving bikes is now higher. (The green zones were installed to keep moving cars from hitting stationary cyclists who were stopped at the intersection.)
> 
> It seems that merging into the traffic flow at intersections--as we teach in our EBBC Street Skills courses--is far safer  than depending on the
> illusory and nonexistent "safety" of a green-painted zone.
> 
> Jon
> 
> Jon Spangler
> Writer/editor
> Linda Hudson Writing
> www.LindaHudsonWriting.net
> TEL  510-864-2144
> CEL 510-846-5356
> [email protected] 
> www.LindaHudsonWriting.net
> www.linkedin.com/in/jonmspangler
> www.twitter.com/jonmspangler
> http://alamedastreetsmarts.wordpress.com/
> 
> 
> "She who succeeds in gaining the mastery of the bicycle will gain the mastery of life."
>   —Frances E. Willard, in A Wheel Within a Wheel: How I Learned to Ride the Bicycle (1895)
> 
> 
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Jon Spangler
Writer/editor
Linda Hudson Writing
www.LindaHudsonWriting.net
TEL  510-864-2144
CEL 510-846-5356
[email protected] 
www.LindaHudsonWriting.net
www.linkedin.com/in/jonmspangler
www.twitter.com/jonmspangler
http://alamedastreetsmarts.wordpress.com/


"She who succeeds in gaining the mastery of the bicycle will gain the mastery of life."
  —Frances E. Willard, in A Wheel Within a Wheel: How I Learned to Ride the Bicycle (1895)

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