Miscommunications based on different meanings of "safe" and their implications for the meaning of safe system

Abstract

Fatal and Severe Injuries (FSI) to vulnerable road users is a major road safety problem internationally. Recent resolutions by the Global Ministerial Conference on Road Safety called for a blanket 30 km/h speed limit in urban areas to address this problem. A project undertaken in Melbourne, Australia, set out to evaluate the effectiveness and benefits of a lower speed limit in a local residential area in the City of Yarra. The intervention comprised replacing 40 km/h speed limit signs in the treated area with 30 km/h signs with an adjacent untreated control area. A before and after study was employed with speed, resident surveys, and estimated safety benefits as measures of its success. Modest reductions in mean speed were observed in the after-phase of the study while benefits were impressive for vehicles travelling at higher speed levels where the risk of severe injury or death is greater. These findings represent an estimated 4% reduction in the risk of severe injury for pedestrians in the event of a collision. Questionnaire responses showed an increased degree of support for the 30 km/h speed limit in local streets in the trial area. The implication of these findings for road safety is discussed, along with the challenges and potential hurdles. Lower speed limits in local streets and municipalities is one important measure to help address vulnerable road users in residential local streets.