During the course of the last several months, some of the largest governing agencies across the United States have started to impose vehicle turn restrictions at key downtown intersections in an attempt to curb vehicle-to-pedestrian conflicts.

San Francisco has unveiled a plan to prohibit left and right turns at several downtown intersections. New York City has asked Google Maps to discourage drivers from turning left in an attempt to make the city’s streets safer.

In simplest form, the idea is to reduce the number of conflict points between drivers, pedestrians, and cyclists on busy corridors, and in doing so, improve safety. Limiting or eliminating vehicle turning options reduces the number of conflict points at traditional intersections.

At signalized intersections, “Permitted” (circular green light – yield to pedestrians) left turns in heavily populated areas have been shown to cause a higher rate of vehicle-to-pedestrian accidents than “protected” (green arrow – no pedestrians) left turns. The danger is sufficiently high that more states and cities are considering prohibiting permitted left turns while pedestrians are present in the crosswalk.

Limiting or eliminating vehicle turning options does come with its share of challenges; it requires carefully planned vehicle routing options to key destinations. Re-routing vehicular traffic may also negatively impact businesses that count on pass-by traffic. These measures require clever engineering and compromise. As an example, San Francisco has compromised on exempting bicycles, trucks, buses and taxis from its turning restrictions.

Given that governing agencies are under increasing pressure to introduce new regulations in order to increase roadway safety for pedestrians and cyclists, these measures are likely to gain momentum and influence in the coming years.