Elvik Rune
Institute of Transport Economics, Gaustadalleen 21, 0349 Oslo, Norway.
Accid Anal Prev. 2017 Mar;100:75-84. doi: 10.1016/j.aap.2016.12.013. Epub 2017 Jan 24.
Several studies have found a so-called safety-in-numbers effect for vulnerable road users. This means that when the number of pedestrians or cyclists increases, the number of accidents involving these road users and motor vehicles increases less than in proportion to the number of pedestrians or cyclists. In other words, travel becomes safer for each pedestrian or cyclist the more pedestrians or cyclists there are. This finding is highly consistent, but estimates of the strength of the safety-in-numbers effect vary considerably. This paper shows that the strength of the safety-in-numbers effect is inversely related to the number of pedestrians and cyclists. A stronger safety-in-numbers is found when there are few pedestrians or cyclists than when there are many. This finding is counterintuitive and one would expect the opposite relationship. The relationship between the ratio of the number of motor vehicles to the number of pedestrians or cyclists and the strength of the safety-in-numbers effect is ambiguous. Possible explanations of these tendencies are discussed.
多项研究发现，对于易受伤害的道路使用者存在一种所谓的“人数安全效应”。这意味着，当行人或骑自行车的人的数量增加时，涉及这些道路使用者与机动车的事故数量的增长幅度小于行人或骑自行车的人数量的增长比例。换句话说，行人或骑自行车的人越多，每个行人或骑自行车的人的出行就越安全。这一发现高度一致，但对“人数安全效应”强度的估计差异很大。本文表明，“人数安全效应”的强度与行人和骑自行车的人的数量呈负相关。行人或骑自行车的人较少时比人数较多时能发现更强的“人数安全效应”。这一发现有违直觉，人们原本预期会是相反的关系。机动车数量与行人或骑自行车的人数量的比例和“人数安全效应”的强度之间的关系并不明确。文中讨论了这些趋势的可能解释。
