Tuesday, August 11, 2009

True or False Sense of Security?

A warning to Angelenos who travel on foot: LADOT is trying to kill you.

What other explanation is there for LADOT's policy not to mark crosswalks--and sometimes to even go so far as to remove them--in the name of "pedestrian safety"? It's like a doctor saying to a patient with cancer, "Well, this medicine isn't working. Let's just do nothing and hope the problem will go away."

To be fair, it isn't just LADOT that thinks this way. Ever since Bruce Herm's 1972 study of crosswalks in San Diego (in which he found more pedestrians were injured or killed in marked crosswalks than unmarked crosswalks) transportation departments across the country have been dutifully scrubbing out zebra stripes in an attempt to protect pedestrians.

The logic behind this seemingly illogical move is the so-called "false sense of security" argument. This much-quoted phrase comes from the Herms study, and represents his attempt to explain why marked crosswalks were riskier for pedestrians than unmarked crosswalks. Herms hypothesized that pedestrians felt so safe between those bright white lines that they threw caution to the wind and boldly stepped out into the road--only to be hit by motorists, who didn't care in the slightest whether the crosswalk was marked or not.

Despite the fact that this was mere speculation on Herms' part (his study wasn't intended to evaluate how carefully pedestrians crossed streets), the idea has become transportation dogma. You can even find it front and center on LADOT's pedestrian policy page, right after the part where we learn that "the Los Angeles Department of Transportation has found that pedestrian accidents are significantly reduced at unmarked crosswalks located at non-street intersections."

I have to wonder where LADOT is getting its data, given that one of the most comprehensive studies on crossing safety, published in 2005 by the FHWA , shows that there is no statistical difference in pedestrian crash rates between marked and unmarked crosswalks on two-lane roads. Not to mention a 2002 FHWA study that found "no evidence" that pedestrians are less vigilant in marked crosswalks.

Admittedly the evidence is not entirely clear-cut. Some recent research does show that pedestrians are less observant when crossing at marked crosswalks. Elderly pedestrians appear to be particularly at risk, as do crossers at high-volume, multi-lane intersections.

I don't dispute that in many cases marked crosswalks alone aren't adequate to protect pedestrians. Sometimes it takes median refuges, flashing lights, raised crossings, or one of the many other solutions have have been shown to increase pedestrian safety at crossings. But the suggestion that the solution to this problem is to remove marked crosswalks?? It really twists my shoelaces into knots. Pedestrians in Los Angeles--and everywhere else--deserve more sophisticated thinking from their policymakers.

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