Results of a study to determine the effect of school speed zones and their enforcement on speeds at school crossings are reported. A series of spot speed studies was conducted at four similar school crossings in Lincoln, Nebraska. Two of the crossings were within school speed zones designated by 25-mile/h speed-limit signs with flashing yellow beacons. The other two crossings were not within school speed zones. The speed studies were conducted during the normal 45-min student crossing period and for 1 h afterward. During the fiveweek period of the study, various levels of enforcement were applied at two of the crossings (one within and one not within a school speed zone). The influence of the school speed zones and levels of enforcement was determined by an analysis of the differences in 85th percentile speeds among the crossings. At all four school crossings studied, traffic speeds were found to be lower under two conditions:(a) when pedestrians were present in the immediate vlcin· ity of the crossing and (b) during the normal 45-min crossing period when pedestrians were not present. However, the degree to which each of these con· ditions reduced speeds was found to be influenced by the 25-mile/h school speed zones and enforcement at the crossings. It was concluded that both school speed zones and enforcement enhance the speed-reduction effects of pedestrian presence and the normal crossing period at school crossings. But, to achieve an acceptable level of compliance, the creditability of school-speed· zone enforcement must be established.

In 1976, in response to citizens' requests for the establishment of 15-mile/h speed zones in advance of school crossings on streets with speed limits of 35-miles/h or higher, the mayor of Lincoln, Nebraska, appointed a special ad hoc committee to study the need for such speed zones and recommend whether or not they should be used in Lincoln. This committee analyzed the pedestrian accident experience in Lincoln and surveyed experience with school speed zones in 25 other cities throughout the country. As a result of its investigation (1), the committee found that