Data from: Highway widening and underpass effects on vertebrate road mortality

Road widening (a.k.a. road dualling) and the presence of mitigation structures may have opposing effects on the number of animal-vehicle collisions. Their influence in tropical areas is poorly quantified, and we know little about how modifications of road structure affect fauna roadkill and mitigation. We evaluated how road widening and proximity to a wildlife underpass affect roadkill of medium and large mammals, using roadkill records from before and after the widening of 150 km of road with new and old wildlife underpasses. Roadkilled species were divided into three groups based on mobility and sensitivity to human disturbance. Four out of 16 species exhibited significantly higher roadkill after widening. Roadkill near underpasses was generally higher than by chance, despite our expectation of reduction of roadkills. This result indicates that we must adopt more effective mitigation measures, such as appropriate fencing combined with underpasses.道路拓宽（road dualling，亦称道路复线工程）与野生动物碰撞减缓设施（mitigation structures）的设置，可能对动物-车辆碰撞事故的数量产生相反的影响。目前学界对这类措施在热带地区的影响量化程度极低，同时对于道路结构改造如何影响野生动物路杀事件及相关减缓措施的效果，我们仍知之甚少。本研究依托150公里道路拓宽工程实施前后的路杀记录，结合该路段配套的新建与既有野生动物地下通道（wildlife underpass），评估了道路拓宽以及距离该类通道的远近对中大型哺乳动物路杀事件的影响。研究团队根据移动性与对人类干扰的敏感性，将受路杀影响的物种划分为三类。在16个受调查物种中，有4个物种在道路拓宽后的路杀数量显著升高。尽管我们原本预期野生动物地下通道周边的路杀事故会有所减少，但实际该区域的路杀数量普遍高于随机水平。这一结果表明，我们需要采用更为有效的减缓措施，例如将合适的围栏与地下通道相结合的方案。