Engineering

Transport engineering

Statistics

Traffic accident

Computer science

Propensity score matching

Mathematics

Geography

Econometrics

Geometry

Matching (statistics)

Medicine

Reduction (mathematics)

Case Studies on Transport Policy

• The effect of the Zone 30 policy on traffic accident reduction was analyzed in Japan. • The propensity score matching method for multiple treatments were used. • Designating an area as a 30-km/h zone could effectively reduce the number of KSI accidents when combined with physical devices. • Utilizing more than two groups was an effective approach for measuring the impact of traffic safety measures. In this study, the effect of the Zone 30 policy on traffic accident reduction in Hyogo prefecture, Japan, was analyzed. Specifically, with the micro-districts (cho-cho-moku) of Hyogo prefecture as the analysis units, statistical verification was performed for the cross-section data of 2017, i.e., a few years after the introduction of the “30-km/h zones,” using the propensity score matching method for multiple treatments. The micro-districts of Hyogo prefecture were classified into three groups: Group 1 with no 30-km/h zones, Group 2 with 30-km/h zones but without physical devices, and Group 3 with 30-km/h zones and physical devices. The primary analysis results were as follows: The number of “Killed” or “Seriously Injured” (KSI) accidents in Group 3 tended to be lower than that in Group 1, whereas there were no significant differences between Groups 1 and 2. Moreover, the total number of traffic accidents in Group 3 was not less than that in Group 1. These results suggest that, at this point, designating an area as a 30-km/h zone, by itself, has negligible effect on reducing traffic accidents; conversely, such areas can effectively reduce the number of KSI accidents when combined with physical devices. In addition, as a verification method, it is empirically demonstrated that utilizing more than two groups is an effective approach for measuring the impact of traffic safety measures.

Verification of Zone-30-policy effect on accident reduction using propensity score matching method for multiple treatments