The use of flashing beacons together with signing has become somewhat standard throughout the country to alert drivers to the presence of school children and to regulate vehicle speed in school zones. Yellow beacons, usually two flashing alternately, may be used with both warning signs and regulatory signs. The only regulatory signs related to school zones are speed-limit signs. Both hazard identification beacons and speed-limit sign beacons are intended to operate only during hours when the warning and speed regulations are in effect. The effectiveness of signs and flashing lights in reducing speeds in school zones has been questioned.

The purpose of this study was to determine the effectiveness of flasher beacons in reducing vehicle speeds in Kentucky. Speed measurements were made during flashing and non-flashing periods at 48 locations. The physical characteristics of each site were identified and compared to speed reductions. A large sample (120 of 424 school flashers currently maintained by the Bureau of Highways in 33 counties in central, northern, and northeastern Kentucky) was inspected to ascertain their condition and operation. This information was helpful in determining the reliability of the beacons in everyday operation.

Report Date


Report Number

No. 450

Digital Object Identifier



Accepted for publication by the Transportation Research Board.