This paper presents a meta-analysis of 33 studies that have evaluated the effects on road safety of areawide urban traffic calming schemes. Such schemes are typically implemented in residential areas in towns in order to reduce environmental and safety problems caused by road traffic. A hierarchical road system is established and through traffic is removed from residential streets. Speed reducing devices and measures are often vital parts. Main roads are improved in order to increase capacity without additional delays or more accidents. The meta-analysis shows that areawide urban traffic calming schemes on the average reduce injury accidents by ca 15 percent. The largest reduction is found for residential streets with ca 25 per cent accident reductions. Similar reductions are found for damage only accidents. The results of the evaluation studies are robust with respect to study design. There is no evidence of publication bias in evaluation studies. Study findings are found to have high external validity. (A)
Abstract