How Design Guidelines Can Reduce Road Safety

Writing in Streetsblog, Kea Wilson explains how the regulations codified in the Manual on Uniform Traffic Control Devices (MUTCD) can make roads less safe.

“Since the very first center line appeared on a Michigan road in 1911, many have questioned whether the design norms that govern the U.S. transportation network really make roads ‘safe,’ or simply less dangerous than the anarchic days of early motordom — though they're still nowhere near as safe as the days before the car dominated American roads at all.”

As transportation engineer Ian Lockwood explains, “The [signs, signals and markings in the] MUTCD aren't there to make our streets safer … They’re there to make them faster.” Signs and markings are designed to speed up traffic, and are less necessary at slower speeds. Cities that have experimented with removing signage and markings have seen positive results. “In 2016, transportation engineers in London found that when they removed center lines from several 30 mile-per-hour roads, traffic speeds and potential crash severity plummeted — perhaps validating Lockwood's hypothesis that the yellow line deserves some of the blame for traffic violence on U.S. roads, too.”

The concept known as Shared Space was pioneered by Dutch traffic engineer Hans Monderman, “who famously — if counter-intuitively — advised communities throughout Europe and Australia facing safety challenges to remove streetlights, lane markers, and even crosswalks, rather than following conventional wisdom that would have them install even more of them.” Lockwood adds that a misplaced faith in technology can cause people to behave less cautiously. “The lower tech we go, the more we have to drive responsibly.”

Despite proven increases in actual safety, pedestrians can perceive Shared Space interventions as making streets less safe. Removing physical curbs can also impede mobility for people with visual impairments who use curbs to identify where the sidewalk ends, for example. 

But the ideology behind Shared Space—the belief that roads should be safe for all people—can be a useful approach for shifting focus away from trying to influence driver behavior with signage and designing safer roadways in the first place.