An interesting excerpt from an essay by Tom Vanderbilt, who has a new book: Traffic: Why We Drive the Way We Do (and What It Says About Us).
In the mid-1980s, Monderman, then a regional safety inspector for Friesland, was dispatched to the small village of Oudehaske to check the speed of car traffic through the town’s center (two children had been fatally struck). Previously, Monderman, like any good Dutch traffic engineer, would have deployed, if not an actual traffic light, the tools of what is known as “traffic calming”: speed bumps, warning signs, bollards, or any number of highly visible interventions.Vanderbilt also reports on what happened when the traffic engineer replaced a traditional intersection with a roundabout:
But those solutions were falling out of favor with his superiors, because they were either ineffective or too expensive. At a loss, Monderman suggested to the villagers, who as it happens had hired a consultant to help improve the town’s aesthetics, that Oudehaske simply be made to seem more “villagelike.” The interventions were subtle. Signs were removed, curbs torn out, and the asphalt replaced with red paving brick, with two gray “gutters” on either side that were slightly curved but usable by cars. As Monderman noted, the road looked only five meters wide, “but had all the possibilities of six.”
The results were striking. Without bumps or flashing warning signs, drivers slowed, so much so that Monderman’s radar gun couldn’t even register their speeds. Rather than clarity and segregation, he had created confusion and ambiguity. Unsure of what space belonged to them, drivers became more accommodating. Rather than give drivers a simple behavioral mandate—say, a speed limit sign or a speed bump—he had, through the new road design, subtly suggested the proper course of action. And he did something else. He used context to change behavior. He had made the main road look like a narrow lane in a village, not simply a traffic-way through some anonymous town.
A year after the change, the results of this “extreme makeover” were striking: Not only had congestion decreased in the intersection—buses spent less time waiting to get through, for example—but there were half as many accidents, even though total car traffic was up by a third. Students from a local engineering college who studied the intersection reported that both drivers and, unusually, cyclists were using signals—of the electronic or hand variety—more often. They also found, in surveys, that residents, despite the measurable increase in safety, perceived the place to be more dangerous. This was music to Monderman’s ears. If they had not felt less secure, he said, he “would have changed it immediately.”Which reminds me of another excellent article, John Staddon's Distracting Miss Daisy: Why stop signs and speed limits endanger Americans, which makes a similar point.