Evaluation of Effectiveness of School Zone Flashers in North Carolina
The North Carolina Department of Transportation has been placing flashing beacons on school zone signs where warranted in an attempt to provide more awareness of the school zone speed limit and at the request of schools. The purpose of this project was to evaluate the effectiveness of placing flashing beacons on school zone speed limit signs and to determine if speed compliance was improved in school zones. A sample set of 15 treatment school zones with flashers and 15 comparison school zones without flashers was selected for analysis throughout North Carolina. Sites were selected to include a mix of geometric features and geographic elements. Flashers had been installed at each of the sites for at least 3 years. The school-time speed limits at all sites ranged between 25 and 45 mph. Speed data were collected at all sites during the reduced-speed school zone hours of operation (school time) and outside the reduced-speed school zone hours of operation (nonschool time). Several different measures of effectiveness were calculated to compare the characteristics of the speed distributions, including the percentage of vehicles exceeding the speed limit, average speed, 85th percentile speed, and pace speed. Results showed no practical difference in vehicle speeds between the flasher and nonflasher locations during school-time hours. Although vehicle speeds did decrease from nonschool-time hours to school-time hours at both flasher and nonflasher sites, the speed reductions were not enough to bring drivers into compliance with the school-time speed limit. Both locations with and without flashers had an extremely low compliance rate with the school-time speed limit.