Which Types of Traffic Signals Are the Safest?

New York experienced major traffic safety improvements during the Bloomberg era, largely as a result of new street designs that offered a model for other U.S. metros to follow. The city hopes to build on that success during the de Blasio era, with the new mayor pursuing a "Vision Zero" plan to eliminate traffic deaths. That plan relies heavily on better enforcement of traffic laws, and despite a shaky start, there's hope it can become a governance model, too.

With so much focus on large-scale design and enforcement measures, it's important to remember that often, the quickest and most direct way a city can improve safety at an intersection is with traffic signals. Traffic lights are neither as ubiquitous as they might seem (even in New York, only a quarter of all intersections have four-way signals) nor as simple. New research in the journal Transport Policy evaluates four common light structures found across the city: basic signal installation, increased pedestrian cycles, the Barnes dance, and split-phase timing.