Pedestrian Safety Guide and Countermeasure Selection System

 

A signalized intersection with a push button pedestrian activated signal. Source: Designing for Pedestrian Safety


 

 

 

Automated Pedestrian Detection

Automated pedestrian detection devices are able to sense when a pedestrian is waiting at a crosswalk and automatically send a signal to switch to a pedestrian WALK phase. Some automated pedestrian detection devices are also able to determine whether a pedestrian needs more time to cross the roadway and will lengthen the crossing interval to accommodate the slower pedestrian. Automated pedestrian detection devices reduce the percentage of pedestrians who cross roadways at inappropriate times, such as when the DON’T WALK signal is visible.

There are generally two types of pedestrian detection technology: microwave and infrared. A delay can be built into either of the devices so that the Walk signal is called only if the pedestrian stays within the detection zone for a certain amount of time. The delay helps to prevent pedestrians who walk by the detection zone from accidentally activating the WALK signal.

Automated pedestrian detection devices called PUFFIN (Pedestrian User-Friendly Intelligent) crossings have been in use in the United Kingdom for several years. They use an infrared detector or pressure-sensitive mat to sense pedestrians waiting for a crosswalk signal. These devices also notice if a pedestrian leaves the area and can cancel the pedestrian walk signal, if necessary. If a pedestrian takes longer than the allotted amount of time to cross the crosswalk, the PUFFIN signal is able to lengthen the WALK signal. PUFFIN crossings reduce the waiting times for pedestrians and motorists by ensuring that no signal is unnecessarily short or long.19

Purpose

At certain pedestrian crossings, it is necessary for a pedestrian to push a button to receive a pedestrian WALK signal. However, studies have shown that many pedestrians ignore the button or believe that the button is malfunctioning if there is a significant delay in receiving a signal.18 Visually impaired pedestrians also might not know that it is necessary to push a button to cross the roadway. Automated pedestrian detection provides more timely pedestrian indications and ensures that pedestrians have enough time to safely cross the roadway.

Considerations

• These types of crossings have been successfully used in Europe for many years. It is important to carefully consider where pedestrian signals for automated pedestrian detection devices are placed.

Estimated Cost

Infrastructure
Description
Median
Average
Min. Low
Max. High
Cost Unit
# of Sources (Observations)
Pedestrian Detection
Furnish and Install Pedestrian Detector
$180
$390
$68
$1,330
Each
7(14)

The cost to install a pedestrian hybrid signal system is approximately $50,000 to $120,000, depending on site conditions and what equipment is already installed. Operation costs are approximately $4,000 per year. Adding automated detectors to an existing pedestrian signal can range from $10,000 to $70,000 per crosswalk.

Safety Effects

A summary of studies that have looked at the safety effects of devices using automated pedestrian detection can be found here.

Case Studies

Las Vegas, Nevada
Village of Great Neck Plaza, New York
San Francisco, California
Tucson, Arizona
Miami-Dade County, Florida