What is an LPI? A Head Start for Pedestrians

(Posted by George Branyan, DDOT’s Pedestrian Program Coordinator)

DDOT in now using a new tool for increasing pedestrian safety. The Leading Pedestrian Interval, or LPI, is a simple signal timing change that can have a big impact on the lives of everyone who crosses the street in the District.  Very simply, a leading pedestrian interval, also known as a “pedestrian head start,” allows the ‘walk’ signal for pedestrians to appear three or more seconds before the green signal for drivers. Because pedestrians can start to cross before the cars begin moving, they are already well into the crosswalk when the signal changes to green. Turning drivers are therefore able to see pedestrians more easily than if they were standing on the curb. This brief timing change allows pedestrians to increase their visibility to drivers who are making turns, especially right turns.

DDOT has installed the LPI treatment at 40 locations so far and has a goal to implement them at 100 intersections by 2012. DDOT looks at crash data to see which intersections are most prone to turning vehicle crashes with pedestrians to prioritize locations for LPIs. You can currently find them on the 15th Street NW corridor, near the U Street/Cardozo Metro station and at many other locations in the Central Business District.

Studies have found that LPIs can dramatically reduce the conflict between turning drivers and pedestrians crossing with the signal at intersections. DC is among several large cities that have begun using the pedestrian-friendly signal timing.

Here’s a video on LPIs in New York City that clearly explains how they work.


Being aware of your surroundings and crossing intersections without being distracted is also a good safe practice.  Safety is a priority.

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