PT - JOURNAL ARTICLE AU - Pengpeng Xu AU - Siqi Xie AU - Ni Dong AU - Sze Chun Wong AU - Helai Huang TI - Rethinking safety in numbers: are intersections with more crossing pedestrians really safer? AID - 10.1136/injuryprev-2017-042469 DP - 2017 Oct 27 TA - Injury Prevention PG - injuryprev-2017-042469 4099 - http://injuryprevention.bmj.com/content/early/2017/10/26/injuryprev-2017-042469.short 4100 - http://injuryprevention.bmj.com/content/early/2017/10/26/injuryprev-2017-042469.full AB - Objective To advance the interpretation of the ‘safety in numbers’ effect by addressing the following three questions. How should the safety of pedestrians be measured, as the safety of individual pedestrians or as the overall safety of road facilities for pedestrians? Would intersections with large numbers of pedestrians exhibit a favourable safety performance? Would encouraging people to walk be a sound safety countermeasure?Methods We selected 288 signalised intersections with 1003 pedestrian crashes in Hong Kong from 2010 to 2012. We developed a Bayesian Poisson-lognormal model to calculate two common indicators related to pedestrian safety: the expected crash rate per million crossing pedestrians and the expected excess crash frequency. The ranking results of these two indicators for the selected intersections were compared.Results We confirmed a significant positive association between pedestrian volumes and pedestrian crashes, with an estimated coefficient of 0.21. Although people who crossed at intersections with higher pedestrian volumes experienced a relatively lower crash risk, these intersections may still have substantial potential for crash reduction.Conclusions Conclusions on the safety in numbers effect based on a cross-sectional analysis should be reached with great caution. The safety of individual pedestrians can be measured based on the crash risk, whereas the safety of road facilities for pedestrians should be determined by the environmental hazards of walking. Intersections prevalent of pedestrians do not always exhibit favourable safety performance. Relative to increasing the number of pedestrians, safety strategies should focus on reducing environmental hazards and removing barriers to walking.