Abstract

Automated Speed Enforcement (ASE) has emerged as a prominent speed enforcement practice, attracting policy attention as its adoption has increased. Although ASE has been widely studied on residential streets and urban corridors, empirical evidence regarding its effectiveness in school zones is limited, where vulnerable road users and time-specific exposure create distinct safety challenges. This study developed Crash Modification Factors (CMFs) for ASE in school zones that quantify the expected change in crash frequency associated with a safety treatment, using before-and-after studies with Empirical Bayes (EB) and comparison group methods. The before-and-after crash studies yielded CMFs below 1.0 in all scenarios considered in this study, indicating the safety benefits of ASE across multiple crash and school categories. The comparison group before-and-after study indicated that, following ASE implementation, total crashes decreased by 10 percent (CMF = 0.90) and 9 percent (CMF = 0.91), while speeding-induced crashes decreased by 35 percent (CMF = 0.65) and 54 percent (CMF = 0.46) for school zones on state-maintained and locally maintained roads, respectively. Thus, estimated CMFs provide quantitative inputs that agencies may consider, indicating that ASE is an effective speed management strategy for improving safety in school zones and justifying investment.

Keywords