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Efficacy of Rectangular-shaped Rapid Flash LED Beacons

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An Analysis of the Efficacy of Rectangular-shaped Rapid-Flash LED Beacons to Increase Yielding to Pedestrians Using Crosswalks on Multilane Roadways in the City of St. Petersburg, FL

Dr. Ron Van Houten
Dr. J. E. Louis Malenfant

Center for Education and Research in Safety

Table of Contents

Executive Summary


Experimental Method

Participants and Setting



Yielding to Pedestrians

Yielding Distances

Driver Passed or Attempted to Pass Stopped Vehicle

Car Behind Yielding Car Jams on Brakes

Experimental Design


Yielding Right-of-way to Pedestrians

Yielding Distance

Driver Passed or Attempted to Pass Stopped Vehicle

Abrupt Braking

Night Evaluation of Rapid-Flash Devices

Inter-Observer Agreement

Statistical Analysis

Comparison with Overhead and Side-Mounted Beacon

Participants and Setting


Experimental Design

Statistical Analysis

Driver Yielding Behavior

Driver Yielding Distance Behavior

Inter-Observer Agreement

Data for All 18 Sites

Data from Other Sites


Determining A Warrant For The Rectangular-Shaped Rapid Flash System


Appendix 1


FIGURE 1 Images depicting potential cause and screening effect of the multiple threat.

FIGURE 2 Picture of two forward-facing rectangular-shaped LED beacon housing.

FIGURE 3 Photograph of the rectangular-shaped rapid flash LED beacon system's pedestrian activation.

FIGURE 4 Photograph showing flags used for measuring motorists' yielding distance as well as an arrow indicating the dilemma zone as calculated using the ITE signal timing formula.

FIGURE 5 Line graphs showing initial yielding compliances for baseline, treatment conditions, and as a set of one year follow-up collection phases. The graphs represent site locations, in order, 22nd Ave. N & 5th St., 1st St. & 37th Ave. N, 31st St. & 54th Ave. N, and 58th St. & 3rd Ave. N.

FIGURE 6 Line graph illustrating nighttime data during initial data collection phases as well as one year follow up for location 1st. St. & 37th Ave. N.

FIGURE 7 Photographs showing a traditional over-head circular incandescent flashing beacon (left photograph) and a round side-mounted beacon (right photograph).

FIGURE 8 Set of two bar graphs illustrating the effectiveness of the rectangular-shaped rapid flash LED beacon when compared to either a traditional over-head mounted or side-mounted circular flashing beacon.

FIGURE 9 Bar graph illustrating the effectiveness of the rectangular-shaped rapid flash LED beacon systems in eliciting yielding compliance averaged across sites for a duration up-to and including one year. One site has also been included that was evaluated at a two year interval.

FIGURE 10 Photograph of one of the two installations in Miami Dade County. The device is a median unit shown during activation.

TABLE 1 Table statistical results from two-sample t-test of independent samples.

TABLE 2 Table of descriptive statistical analysis of yielding distances in percentages recorded during each treatment condition averaged across sites.