Traffic Research Unit, Department of Psychology, University of Helsinki, Finland.
Traffic Inj Prev. 2010 Feb;11(1):87-95. doi: 10.1080/15389580903471126.
Current European legislation allows the EU member states to restrict the maximum power output of motorcycles to 74 kW even though evidence supporting the limit is scarce and has produced mixed results-perhaps because motorcycle performance has been measured by engine displacement, not engine power, in most of the previous studies. This study investigates the relationship of motorcycle engine power and power-to-weight ratio to risk of fatal and nonfatal crashes in Finland.
The fatality rate (number of fatal accidents/number of registered motorbikes) for riders of different ages riding bikes belonging to different power and power-to-weight ratio classes was examined using a comprehensive in-depth database. Data on nonfatal accidents were acquired from a Web questionnaire (N = 2708), which also served as a basis for estimating riders' annual mileage. Mileage data allowed the calculation of accident risk per kilometer ridden for bikes differing in power and power-to-weight ratio.
The fatality risk per number of registered motorcycles and per kilometer ridden increases both with power and power-to-weight ratio, independently of rider's age. No relationship between performance and risk of a less severe crash was found. The pre-accident speed of the most powerful bikes was 20 km/h or more over the speed limit in a large proportion of the fatal accidents (odds ratio = 4.8 for > 75 kW motorbikes; odds ratio = 6.2 for > 0.3 kW/kg motorbikes).
The risk of being involved in a fatal crash is higher among the riders of powerful motorcycles. However, it is not clear whether the results are related to the riding habits of the riders that choose the most powerful bikes available or whether the high risk is due to the properties of the bikes themselves. Therefore, further research is needed before considering legal limits on motorcycle performance.
目前，欧洲法规允许欧盟成员国将摩托车的最大功率输出限制在 74kW 以内，尽管支持这一限制的证据很少，且此前的研究结果也不尽相同——这或许是因为此前的大多数研究都是根据发动机排量而不是发动机功率来衡量摩托车性能。本研究旨在调查芬兰摩托车发动机功率和功率重量比与致命和非致命事故风险之间的关系。
利用全面深入的数据库，研究了不同年龄段骑手驾驶不同功率和功率重量比等级摩托车的死亡率（致命事故数/注册摩托车数）。非致命事故数据来自网络问卷调查（N=2708），该调查还为估算骑手的年行驶里程提供了依据。里程数据允许计算不同功率和功率重量比的摩托车每行驶一公里的事故风险。
无论骑手年龄大小，每注册一辆摩托车和每行驶一公里的死亡率都随着功率和功率重量比的增加而增加。未发现性能与较轻微事故风险之间存在关联。在大多数致命事故中，最强大的摩托车在事故发生前的速度超过限速 20km/h 或以上（功率超过 75kW 摩托车的比值比=4.8；功率重量比超过 0.3kW/kg 摩托车的比值比=6.2）。
大功率摩托车骑手发生致命事故的风险更高。然而，目前尚不清楚这些结果是与骑手的骑行习惯有关（他们选择了最强大的摩托车），还是与摩托车本身的特性有关。因此，在考虑对摩托车性能进行法律限制之前，还需要进一步研究。
