Abstract

Southern European countries such as Portugal still have a low bicycle share (up to 1%). Therefore, it is fundamental to research the potential benefits and drawbacks of modal shifts. This work analyses the implementation of a bike-sharing system (BSS) and its expected implications in emission reductions from road traffic for the case study of Coimbra city, Portugal. Although many different pollutants result from road traffic, we focused on small Particulate Matter (PM_2.5) due to its harmful effects on human health. The methodology considers an integrated set of models for a) estimation of potential demand for the use of bike-sharing; b) mobility studies for the analysis of travel behavior; c) optimization modeling for the location of the bike-sharing stations and d) traffic emission modeling, to estimate the reduction of emissions due to bike-sharing modal shift. We considered two different potential scenarios for the location of bike stations. A modal share shift from car use toward bicycle in each is assumed, and the consequent traffic reduction and the associated emissions reduction are analyzed. The results show a non-homogeneous relation between traffic reduction and emission reduction across the urban space, achieving 12.5% of daily PM_2.5 emissions in some urban roads.

摘要

葡萄牙等南欧国家的自行车份额仍然很低（高达 1%）。因此，研究模态转换的潜在利弊至关重要。这项工作分析了自行车共享系统 (BSS) 的实施及其对减少道路交通排放的预期影响，以葡萄牙科英布拉市为例。尽管道路交通会产生许多不同的污染物，但我们专注于小颗粒物（PM _2.5) 由于其对人体健康的有害影响。该方法考虑了一套综合模型，用于 a) 估计使用共享单车的潜在需求；b) 用于分析旅行行为的流动性研究；c) 共享单车站点位置的优化建模和 d) 交通排放建模，以估计由于共享单车模式转变导致的排放减少。我们考虑了自行车站位置的两种不同的潜在情景。假设在每种情况下都存在从汽车使用向自行车使用的模式份额转移，并分析了随之而来的交通减少和相关的排放减少。结果表明，整个城市空间的交通减少和减排之间存在非同质关系，在一些城市道路上实现了每日 PM _{2.5排放量的 12.5%。}