Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Queensland University of Technology, School of Psychology and Counselling, Brisbane 4059, Australia.
Accid Anal Prev. 2022 Oct;176:106818. doi: 10.1016/j.aap.2022.106818. Epub 2022 Aug 26.
In the past decades, trees were considered roadside hazard. Street trees were removed to provide clear zone and improve roadside safety. Nowadays, street trees are considered to play an important role in urban design. Also, street tree is considered a traffic calming measure. Studies have examined the effects of urban street trees on driver perception, driving behaviour, and general road safety. However, it is rare that the relationship between urban street trees and pedestrian safety is investigated. In this study, a micro-level frequency model is established to evaluate the effects of tree density and tree canopy cover on pedestrian injuries, accounting for pedestrian crash exposure based on comprehensive pedestrian count data from a state in Australia, Melbourne. In addition, effects of road geometry, traffic characteristics, and temporal distribution are also considered. Furthermore, effects of spatial dependency and correlation between pedestrian casualty counts of different injury severity levels are accounted using a multivariate Bayesian spatial approach. Results indicate that road width, bus stop, tram station, on-street parking, and 85th percentile speed are positively associated with pedestrian casualty. In contrast, pedestrian casualty decreases when there is a pedestrian crosswalk and increases in tree density and canopy. Also, time variation in pedestrian injury risk is significant. To sum up, urban street trees should have favorable effect on pedestrian safety. Findings are indicative to optimal policy strategies that can enhance the walking environment and overall pedestrian safety. Therefore, sustainable urban and transport development can be promoted.
在过去的几十年里，树木被认为是道路旁的障碍物。为了提供清晰的区域并提高道路安全，路边的树木被移除。如今，街道树木被认为在城市设计中起着重要作用。此外，街道树木被认为是一种交通缓行措施。研究已经研究了城市街道树木对驾驶员感知、驾驶行为和一般道路安全的影响。然而，很少有研究调查城市街道树木与行人安全之间的关系。在这项研究中，建立了微观频率模型来评估树木密度和树冠覆盖率对行人伤害的影响，该模型考虑了基于澳大利亚墨尔本全面行人计数数据的行人碰撞暴露率。此外，还考虑了道路几何形状、交通特征和时间分布的影响。此外，使用多变量贝叶斯空间方法来考虑不同伤害严重程度的行人伤亡计数之间的空间相关性和相关性的影响。结果表明，道路宽度、公共汽车站、电车车站、路边停车和 85%分位速度与行人伤亡呈正相关。相反，当有行人横道时，行人伤亡减少，而树木密度和树冠增加。此外，行人受伤风险的时间变化是显著的。总之，城市街道树木应该对行人安全有有利的影响。研究结果表明，可以采取优化政策策略来改善步行环境和提高整体行人安全，从而促进可持续的城市和交通发展。
