On the Life-Saving Potential of Leading Pedestrian Intervals

Leading pedestrian intervals, or LPIs, are traffic signals that give pedestrians a few seconds of walking time before cars enter the intersection. Laura Bliss covers how they've been linked to lower fatalities where they're installed.

"Given even a few seconds of priority," Bliss writes, "most [pedestrians] wind up at least halfway into the crosswalk—where they're plenty visible to drivers—before cars are allowed to go straight or make turns (including the ultra-dangerous left)."

Cities like San Francisco, Los Angeles, and Seattle have all been experimenting with LPIs as part of their Vision Zero platforms. But as we've seen, New York City has achieved the best outcomes so far. NYC boasts 2,483 LPIs, and "a 2016 study of 104 intersections by the NYC Department of Transportation found that pedestrian and bike fatalities and severe injuries declined by nearly 40 percent at locations where LPIs have been installed."

Among Vision Zero enhancements, LPIs stand out for their comparatively low costs. According to a New York City DOT spokesperson, Bliss reports, the average cost per crosswalk is just $1,200.