Greater Greater Washington

Pedestrians


Traffic engineers still rely on a flawed 1970s study to reject crosswalks

When St. Louis decided not to maintain colorful new crosswalks that residents had painted, the city's pedestrian coordinator cited federal guidance. A 2011 FHWA memo warns that colorful designs could "create a false sense of security" for pedestrians and motorists.


Shoddy, 50-year-old research is an obstacle to grassroots street safety efforts like this fleur-de-lis crosswalk in St. Louis. Photo from Rally St. Louis.

That may sound like unremarkable bureaucrat-speak, but the phrase "false sense of security" is actually a cornerstone of American engineering guidance on pedestrian safety.

You'll find the words "false sense of security" in Washington state DOT's crosswalk guidelines too. The city of Stockton, California, makes the same claim. The list goes on.

What gives? Well, you can trace this phrase—and the basis of some engineers' reluctance to stripe crosswalks—to one very influential but seriously flawed study from the 1970s.

In 1972, a researcher named Bruce Herms conducted a study of crosswalk safety in San Diego. He found that intersections with marked crosswalks had higher injury rates than ones with unmarked crosswalks. He concluded that marked crosswalks should only be installed where they are "warranted" because they can give pedestrians a "false sense of security," encouraging risky behavior.

But there were problems with the study. For one, Herms didn't actually study why people made certain decisions at crosswalks—that "false sense of security" was just speculation on his part.

Since the Herms study, other studies have refuted his conclusions, including work produced by the FHWA. Nevertheless, the influence of his research from more than 40 years ago persists. As backward as it seems, engineers still refuse to install crosswalks on the grounds that it would harm pedestrian safety. Just a few years ago, for instance, the "false sense of security" argument was deployed to shoot down requests for midblock crossings in Los Angeles.

Bill Schultheiss, an engineer with the Toole Design Group and member of the bike and pedestrian committee of the National Committee on Uniform Traffic Control Devises, is critical of the Herms study.

"When I first came into engineering, I heard a lot about this idea of pedestrians having a false sense of security when in marked crosswalks," he said. "And I just believed it."

But then Schultheiss ordered a print copy of the study to review it.

"I think it was biased," he said, like much of the older regulations. "I don't know, was it him or just the culture at the time."

"His conclusions were terrible."

For example, Herms found that of the pedestrians who were struck, most were hit in the middle or near the end of the crosswalk, not at the beginning. This is a pattern that suggests motorists are failing to yield to people who have already established themselves in the crosswalk, not that people are stepping off the curb inattentively.

"If you make it three quarters of the way across the street, you expect cars to stop," Schultheiss said. "That's the law."

Despite the absence of evidence to back it up, the idea that crosswalks encourage pedestrians to engage in risky behavior continues to enjoy credence in the engineering profession. Official memos like FHWA's 2011 guidance on crosswalk art repeat and endorse the idea, squashing grassroots street safety efforts.

Crossposted from Streetsblog USA.

Angie Schmitt is a Cleveland-based writer and activist who specializes in transportatin planning and Midwestern cities. She manages the national sustainable transportation advocacy blog, Streetblog.net. Angie is a former newspaper reporter with a masters degree in urban planning, design and development. 

Comments

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That's a shame that St. Louis won't maintain those crosswalks. Those designs are tasteful and add flair to the neighborhood.

The Barnes Dance crosswalk in our Chinatown will be adorned this spring by local artist Charles Bergen.

https://www.facebook.com/CharlesBergenStudios/photos/a.287576724715842.1073741841.279500892190092/599524366854408/?type=3&theater

by MB on Feb 15, 2016 11:58 am • linkreport

I'm proud that my town (in MA) has green-striped crosswalks. I also believe that they are effective at making peds safer, though I have no data to prove it.

by Lance B on Feb 15, 2016 3:01 pm • linkreport

In Taiwan, executives (and engineers?) who built the building that collapsed in the recent earthquake have been charged with "professional negligence resulting in death." Perhaps traffic engineers responsible for so many unnecessary deaths on our roads should be similarly brought to public trial? I'd like to hear their defenses under oath.
http://www.cnn.com/2016/02/09/asia/taiwan-earthquake-rescue/

by Greenbelt on Feb 15, 2016 5:33 pm • linkreport

@Greenbelt, they'd say they're following standard patterns and procedures that everyone else is using, and they'd be able to cite a lot of precedent to back them up.

Traffic engineers aren't "evil". The problem is systemic. It's somewhat ideological in nature, but it's not un-overcomeable. It's getting there . . . slowly.

I have to assume that the younger generation is increasingly leaning more towards recognizing the "goodness" of the "Complete Street" ideologies and the like, because things are shifting.

by Joey on Feb 15, 2016 8:37 pm • linkreport

Tangential traffic study, possibly OT: Is anyone going to run a survey to update the "85th percentile is the safe speed and should be the speed limit" rule of thumb for this century?

When was that study made? Can it possibly hold true while cars get faster, heavier, more powerful, and easier to drive at higher speeds comfortably, on ever-more-crowded roads?

by KadeKo on Feb 16, 2016 11:03 am • linkreport

Seriously, what do traffic engineers believe that isn't completely flawed? Add this to: sizing of parking lots, induced traffic, driver response to removal of road hazards. And probably lots more.

Traffic engineering is a modern-day theory of phlogiston.

by thm on Feb 16, 2016 5:09 pm • linkreport

@Joey "Traffic engineers aren't "evil". The problem is systemic. It's somewhat ideological in nature, but it's not un-overcomeable. It's getting there . . . slowly."

Correct or their professional society would not publish documents with Congress for the New Urbanism like Designing Walkable Urban Thoroughfares: A Context Sensitive Approach: An Institute of Transportation Engineers Recommended Practice.

Some traffic engineers are, indeed, part of the solution; primarily since their peers listen to them.

by Some Ideas on Feb 16, 2016 5:20 pm • linkreport

Regarding the 85th percentile thing, isn't a common complaint about speed limits in the US that speed limits get pegged well below the 85th percentile speed in order to allow more speeding tickets to be issued?

by Jason on Feb 16, 2016 9:35 pm • linkreport

Regarding the 85th percentile thing, isn't a common complaint about speed limits in the US that speed limits get pegged well below the 85th percentile speed in order to allow more speeding tickets to be issued?

Perhaps from the driving public. The main critique of the "85th percentile rule" around here seems to be that drivers operate at a safe speed for the road and conditions--so long as there are no pedestrians, cyclists or other road users.

by oboe on Feb 17, 2016 7:43 am • linkreport

FHWA's latest publication on methods and practices for setting speed limits...provides more on the background for your question.
http://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa12004/

by Some Ideas on Feb 17, 2016 7:36 pm • linkreport

No idea what this story has to do with what st.louis did. They didn't ban crosswalks. They banned branded crosswalks because MUTCD didn't allow them. MUTCD crosswalks are still allowed. They went away from branded because a lawyer would have been all over the city like a fat kid on cake if their client was hit in a non compliment MUTCD crosswalk

by DB on Feb 21, 2016 10:37 pm • linkreport

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