Wednesday, December 17, 2008

Cui bono?

Cui bono?” is Latin for “who benefits?” Regular CycleDog readers know that I believe bike lanes primarily benefit motorists by moving cyclists out of the way. Motorists get to drive faster, and as we all know, anything that reduces speed is somehow sinful. Cyclists receive no real safety benefit from this, though as this study points out, many believe they're safer. Studies like this are much like asking a fire-and-brimstone preacher about his views on biology. His answer may be heartfelt and both interesting and entertaining, but it has little scientific credibility.

A more appropriate title would be “Survey Reveals Cycling Misconceptions” but then again, truthiness is what counts. My comments are in italics.

Texas State Bicycle Survey Reveals Danger Concerns, Cycling Perceptions


ScienceDaily (Dec. 15, 2008) — Bicyclists in Dallas, Houston and San Antonio are more concerned with being involved in vehicle crashes compared to bicyclists in other Texas cities, according to a survey conducted by the Center for Transportation Research at The University of Texas at Austin.

“This is quite intuitive, given the high levels of traffic congestion in Houston, Dallas and San Antonio,” said Professor Chandra Bhat, who spearheaded the survey and is one of the world’s foremost authorities on travel behavior. OTHER WORKS BY PROFESSOR CHANDRA BHAT?

In addition, almost 70 percent of the survey respondents feel bicycling is “very dangerous” or “somewhat dangerous” in terms of traffic accidents. (Emphasis added.)

Let's say that again, “respondents feel bicycling is very dangerous or somewhat dangerous.” This is like asking my elderly aunt if she feels safe driving in high speed traffic. It's an entirely different question as to whether she's genuinely safe. This is the difference between perception and reality, and if we're going to spend public money on bicycling facilities, let's spend in ways that provide real safety improvements rather than imaginary ones.

...The survey, sponsored by the Texas Department of Transportation and the Federal Highway Administration, was conducted entirely online. The results should help establish planning guidelines for the design of safe and efficient bicycle facilities and environments in Texas and around the country.

Like any other on-line survey, the respondents are self-selected, so there's no semblance of a random sample of the population as a whole or even the cycling population in general. Furthermore, there's no way to prevent anyone from completing the survey more than once, thereby skewing its results. It's easy to delete any tracking cookie and retake the survey, so the results should be regarded as suspect unless another more scientifically rigorous study corroborates them. Until then, this one has all the credibility of a survey printed on the backside of a breakfast cereal box. Collecting people's 'feelings' about bicycling may be an interesting pursuit, but it should not be the basis of public policy. When have we ever established design guidelines for interstate highways, for instance, by collecting motorist's perceptions of safe design? Using that kind of reasoning, we should disband the FAA and let airline passengers decide if an aircraft is safe or not. Madness.

Respondents were 18 years or older living in more than 100 Texas cities. The sample included 1,605 bicyclists, of which 810 (or slightly more than 50 percent) used their bikes for commuting. The remaining 795 bicycled only for non-commuting purposes. Each group was presented with questions pertaining to their particular habits.

Again, if industry statistics are to be believed, commuting cyclists comprise only about 10% of all cyclists. The NBDA says there are about 50 million cyclists in the US, though they include anyone who's ridden a bicycle even once in the last year. Estimates of bicycle commuters vary from 5 to 6 million. So the Texas figure citing nearly half the survey respondents as commuter cyclists is highly suspect. To be fair, however, the differences may lie in the sampling procedure, so I'll have to read the original study if it's available. More on this later.

Bhat said the transportation sector accounts for about one-third of all human-generated greenhouse gas emissions. Within that sector, travel by personal vehicles accounts for nearly two-thirds of those emissions. And only 0.9 percent of all trips in the United States are made by bicycle, and the number drops to 0.4 percent for commute trips -- despite the fact that a significant amount of trips are deemed short-distance and can be made using a bike. A 2001 National Household Travel Survey revealed that 41 percent of all trips in 2001 were shorter than two miles and 28 percent were shorter than one mile.

Read that again – personal vehicles account for two-thirds of all greenhouse gas emissions AND cyclists comprise 0.9 percent of all wait for it!

Bhat’s research attempts to understand the reasons for the low bicycling use and inform the development of appropriate and effective strategies to increase bicycling, thereby cutting down motorized vehicle use and carbon dioxide emissions while promoting a healthier, more physically active lifestyle.

There! It was inevitable. He trotted out the shop-worn argument that increasing bicycle usage will result in a reduction of greenhouse gases. Let's see, my schoolboy math skills may be a little rusty, but if I've figured this correctly, tripling the number of bicycling trips will reduce greenhouse gases by an astonishing one-and-a-half percent (roughly). It seems to me that by setting the thermostat a little lower and driving fewer miles, we accomplish the same thing. I still drive about 6000 miles per year, so if I drive 60 fewer miles, I've reached one percent. While it's depressing to admit, gasoline prices will have a greater effect on greenhouse gas reduction than any effort we make at encouraging cycling.

One finding that may have immediate relevance is that individuals who have a more positive perception of the quality of bicycle facilities have a higher propensity to bicycle to work.

Bicycle commuters who deal with motor vehicle traffic on a daily basis are more likely to have a higher positive perception of a given roadway than recreational or casual cyclists, making the presence or absence of facilities irrelevant.

Finally, there's this whopper:

...Bicyclists prefer no parking on their route, which is logical because parking reduces sight distance. If parking is necessary, they prefer angled parking over parallel parking. (Emphasis added.)

Angled parking is a nightmare for anyone traveling on two wheels. It's even worse if some benighted planner puts a bike lane right behind all those car bumpers, putting cyclists in the worst possible lane position. I think the AASHTO manual specifically recommends to avoid routing bicyclists directly behind such parking. Developers, on the other hand, absolutely love angled parking because they can fit more cars along a given length of street. So you have to wonder who completed the survey, cyclists or someone else.

Cui bono?




Blogger lemmiwinks said...

Nose in angle parking is just crazy. Most places down here it's rear in which is nowhere near as bad.

3:32 PM  

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