A detailed study of signs with flashers in school zones was conducted to determine their effectiveness in reducing the speeds of vehicles during times of pedestrian activity. Field investigations were conducted at all of the 120 flasher locations in Highway Districts 6, 7, and 9. About 14 percent of the flashers were inoperative. Such problems as non-uniform signing, hidden flashers, deteriorating signs and pavement markings, and poor sight distances were also found.

Speed studies were conducted at 48 locations. Average speed reductions were only 3.6 mph (1.6 m/s) during flashing periods. Signs and flashers at high-speed (55-mph (25-m/s)) locations increased the potential for inter-vehicle accidents due to decreased speed uniformity. Crossing guards caused reductions in vehicle speeds to within the 25-mph (11-m/s) limit. Speed enforcement, minimal periods of flashing, good sight distance, and proper maintenance of signs and flashers were shown to improve their effectiveness in reducing speeds.

Report Date


Report Number

No. 429

Digital Object Identifier



The contents of this report reflect the views of the author who is responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Bureau of Highways. The report does not constitute a standard, specification, or regulation.