Marqués R, Hernández-Herrador V
Department of Electronics and Electromagnetism, Faculty of Physics, University of Seville, Av Reina Mercedes s/n, 41012 Sevilla, Spain.
Independent Consultant, Santa Cleta Soc. Coop. And, C/Fray Diego de Cádiz, 24, 41003 Sevilla, Spain.
Accid Anal Prev. 2017 May;102:181-190. doi: 10.1016/j.aap.2017.03.004. Epub 2017 Mar 16.
We analyze the evolution of the risk of cycling in Seville before and after the implementation of a network of segregated cycle tracks in the city. Specifically, we study the evolution of the risk for cyclists of being involved in a collision with a motor vehicle, using data reported by the traffic police along the period 2000-2013, i.e. seven years before and after the network was built. A sudden drop of such risk was observed after the implementation of the network of bikeways. We study, through a multilinear regression analysis, the evolution of the risk by means of explanatory variables representing changes in the built environment, specifically the length of the bikeways and a stepwise jump variable taking the values 0/1 before/after the network was implemented. We found that this last variable has a high value as explanatory variable, even higher than the length of the network, thus suggesting that networking the bikeways has a substantial effect on cycling safety by itself and beyond the mere increase in the length of the bikeways. We also analyze safety in numbers through a non-linear regression analysis. Our results fully agree qualitatively and quantitatively with the results previously reported by Jacobsen (2003), thus providing an independent confirmation of Jacobsen's results. Finally, the mutual causal relationships between the increase in safety, the increase in the number of cyclists and the presence of the network of bikeways are discussed.
我们分析了塞维利亚市实施自行车专用道网络前后骑自行车风险的演变情况。具体而言，我们利用交警在2000年至2013年期间报告的数据，即自行车道网络建成前后各七年的数据，研究了骑自行车者与机动车碰撞风险的演变。在自行车道网络实施后，观察到此类风险突然下降。我们通过多线性回归分析，借助代表建成环境变化的解释变量，特别是自行车道的长度以及一个在网络实施前后取值为0/1的逐步跳跃变量，来研究风险的演变。我们发现，最后这个变量作为解释变量具有很高的值，甚至高于网络的长度，这表明自行车道网络化本身对骑行安全有重大影响，且不仅仅是自行车道长度的增加。我们还通过非线性回归分析来分析数量安全。我们的结果在定性和定量方面与雅各布森（2003年）先前报告的结果完全一致，从而为雅各布森的结果提供了独立验证。最后，讨论了安全增加、骑自行车者数量增加与自行车道网络存在之间的相互因果关系。
