Whitlock & Weinburger Report – The original study conducted on IRWL enhanced crosswalks systems that paved the way for acceptance by the Federal Highway Administration as a standard in the Manual on Uniform Traffic Control Devices (MUTCD), Section 4L.

FINDINGS

1. The concept of flashing amber lights embedded in the pavement at uncontrolled crosswalks clearly has a positive effect in enhancing a driver’s awareness of crosswalks and modifying driving habits to be more favorable to pedestrians.
2. The In-Pavement Flashing Lights Crosswalk Warning System has a much more significant effect in enhancing a driver’s awareness of crosswalks during adverse weather conditions such as darkness, fog, and rain.
An Evaluation Of A Crosswalk Warning System Utilizing In-Pavement Flashing Lights.

Kirkland Study – This study was conducted by the City of Kirkland, Oregon regarding their experience and results with flashing crosswalks, how the system works, how it was installed, and their effectiveness in causing vehicles to respond to pedestrians; i.e.: “The data suggests that the devices are effective in both increasing the number of drivers that yield to pedestrians and the distance from the crosswalk where drivers apply their brakes.”
For complete study – City of Kirkland, Oregon IRWL system study

Evaluation of In-Pavement flashing Lights on a Six-Lane arterial Pedestrian Crossing by Dr. Panos D. Prevedouros of the University of Hawaii Study. He conducted the study on the LightGuard IRWL installation on Pali Highway at the intersection of Jack Lane & Akamu Place.
1. Key results include the following: The effect on speeds was dramatic. On the north bound direction, maximum speed decreased by 16.2% and average speed decreased by 25.2% when the lights are activated. On the south bound direction, maximum speed decreased by 17.8% and average speed decreased by 27.2%.
2. The average wait time at the curb was reduced from 26.7 to 13.2 seconds. The proportion of pedestrians who crossed entirely outside the marked crosswalk decreased from 15.9% to 8.3%.
3. The evaluation showed that this experimental application of in-pavement flashing lights produced positive results. HDOT’s action to deploy this technology as a stopgap measure was appropriate and successful.
Evaluation of In-Pavement flashing Lights on a Six-Lane arterial Pedestrian Crossing

This study specifically compares the effectiveness of overhead lights & beacons to In-roadway Warning Light (IRWL) systems. Conclusion: “… the experimental embedded pavement light system was found to be more effective at alerting motorists of pedestrian presence in the crosswalk that the standard overhead yellow flashing beacon…”
Crosswalk Enhancement Comparison Study – Overhead Beacons vs. IRWL System

A summary report by the Transportation Research Board regarding in-pavement signal light applications at crosswalks, intersections, highway-rail crossings, lane delineators, and other applications. Released June 2008.
NCHRP Report: Applications of Illuminated, Active In-Pavement Marker Systems

1) Summary of EXPERIMENTAL TRAFFIC CONTROL DEVICE APPLICATION … The City of Anaheim requested permission from the California Traffic Control Devices Committee (CTCDC) for in-pavement signal lights to flash in conjunction with overhead stop lights. the in-pavement signal lights flashed in an amber color during the warning yellow phase and changed to red color at the red stop light phase.
Summary of EXPERIMENTAL TRAFFIC CONTROL DEVICE APPLICATION

2) Mid-Block Pedestrian Crosswalk, Traffic Engineering Study – The purpose of this study is to test the use of in-pavement signal lights installed at the stop bar of a pedestrian-actuated signalized, mid-block crosswalk. This crosswalk is located on West Alabama Street in the Uptown District of Houston, Texas. Study was conducted in June of 2003.

The Study “… confirms recognition of the in-roadway LED lights as traffic control devices worth complying with, and that the lights aid motorist to stop at an appropriate distance behind the stop bar.”
Mid-Block Pedestrian Crosswalk, Traffic Engineering Study

The highway–rail crossing is located at the intersection of Paramount Boulevard and Rosecrans Avenue in Paramount, California. The location is unusual because the railroad crosses diagonally through the intersection and not just across one approach. The intersection was too wide for regular railroad crossing gates, and the typical railroad crossing lights would have visually blocked the existing traffic signal faces. The in-pavement TraxAlert™ system works with the existing overhead signal lights, providing a safe crossing at the intersection.
Report on TraxAlert™ Installation in Paramount California