Traffic control - In-pavement flashing lights

In-pavement lights are used at crosswalks to alert motorists that pedestrians are crossing or preparing to cross a street. The amber lights are embedded in the pavement on both sides of the crosswalk and oriented to face oncoming traffic. When the pedestrian activates the system, either by using a push-button or through automatic detection, the lights begin to flash at a constant rate, warning the motorist that a pedestrian is in the vicinity of the crosswalk ahead.

The amber LED lights flash in unison at a rate designed for maximum motorist recognition and are visible during the daylight as well as at night. The flashing lights are only activated when a pedestrian wants to cross and are automatically shut off after a set period of time that is assumed to be sufficient to allow a pedestrian to safely cross the street. If installed in conjunction with the means to detect the presence of pedestrians while in the crosswalk, the crossing interval can be extended, in which case the lights would continue to flash and allow slower pedestrians to safely cross.

A study of the effectiveness of in-pavement flashing lights at uncontrolled pedestrian crossings by Hakkert et al. (2001) found that vehicle speeds near crosswalks decreased slightly (2-5 km/h), the rate of drivers yielding to pedestrians doubled and the rate of pedestrian-vehicle conflicts decreased from 17% to 1%. The results of a similar study by Prevedouros (2001) at an uncontrolled pedestrian crossing were also positive. When in pavement lights were activated, average vehicle speeds decreased by 25%, the percentage of drivers who slowed/stopped for pedestrians doubled and the percentage of drivers who did not yield to pedestrians decreased to 8% from 31%.

Godfrey et al. (1999) found that in-pavement flashing lights were effective in both increasing the number of drivers that yielded to pedestrians and the distance from the crosswalk where drivers applied their brakes.

Evidence

• Hakkert AS, Gitelman V, Ben-Shabat E. An evaluation of crosswalk warning systems. Proceedings of the 80th Annual Meeting of the Transportation Research Board [CD-ROM]. Washington, DC: Transportation Research Board; 2001. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447993/table/t2/
• Prevedouros PD. Evaluation of in-pavement flashing lights on a six-lane arterial pedestrian crossing. Proceedings of the 71st Annual Meeting of the Institute of Transportation Engineers [CDROM]. Washington, DC: Institute of Transportation Engineers; 2001. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447993/table/t2/
• Godfrey, D, Mazzella, T. Kirkland's Experience with In-Pavement Flashing Lights at Crosswalks. ITE/IMSA Annual Meeting, Lynnwood, Washington, 1999. Retrieved from http://www.kirklandwa.gov/depart/Public_Works/Transportation___Streets/Kirkland_s_Experience_with_In-pavement_Flashing_Crosswalks.htm