Institute of Transport Economics, Gaustadalléen 21, Oslo NO-0349, Norway.
Accid Anal Prev. 2009 Jul;41(4):849-55. doi: 10.1016/j.aap.2009.04.009. Epub 2009 May 9.
Several studies show that the risks of injury to pedestrians and cyclists are highly non-linear. This means that the more pedestrians or cyclists there are, the lower is the risk faced by each pedestrian or cyclist. On the other hand, the more motor vehicles there are, the higher becomes the risk faced by each pedestrian or cyclist. The relationships found in previous studies suggest that if very large transfers of trips from motor vehicles to walking or cycling take place, the total number of accidents may be reduced. The "safety in numbers" effect for pedestrians and cyclists would then combine favourably with the effect of a lower number of motor vehicles to produce a lower total number of accidents. This paper explores if such an effect is possible, relying on the findings of studies that show the non-linearity of injury risks for pedestrians and cyclists. It is found that for very large transfers of trips from motor vehicles to walking or cycling, a reduction of the total number of accidents is indeed possible. This shows that the high injury rate for pedestrians and cyclists in the current transport system does not necessarily imply that encouraging walking or cycling rather than driving will lead to more accidents.
多项研究表明，行人和骑车人的受伤风险呈高度非线性。这意味着，行人和骑车人的数量越多，每个行人和骑车人面临的风险就越低。另一方面，机动车数量越多，每个行人和骑车人面临的风险就越高。以往研究中发现的关系表明，如果大量的出行从机动车转移到步行或骑行，事故总数可能会减少。这样，行人和骑车人的“数量安全效应”将与机动车数量减少的效应相结合，从而产生较低的事故总数。本文探讨了这种效应是否可能，它依赖于表明行人和骑车人受伤风险呈非线性的研究结果。研究发现，对于大量的出行从机动车转移到步行或骑行，确实有可能减少事故总数。这表明，在当前的交通系统中，行人和骑车人的高受伤率并不一定意味着鼓励步行或骑行而不是开车会导致更多的事故。
