[论文解读] Impact Of Bike Sharing In New York City

Stanislav Sobolevsky, Ekaterina Levitskaya+3 more|arXiv (Cornell University)|Aug 20, 2018

Urban Transport and Accessibility参考文献 13被引用 5

一句话总结

本文提出了一种交通选择模型，用于估算纽约市Citi Bike系统对通勤行为的基准影响，避免对替代出行方式做出任意假设。利用开放数据，该模型量化了经济、社会和环境维度的直接效益——在所有五个行政区及霍博肯市均显示出显著的时间与成本节约、排放减少以及体力活动增加。

ABSTRACT

The Citi Bike deployment changes the landscape of urban mobility in New York City and provides an example of a scalable solution that many other large cities are already adopting around the world. Urban stakeholders who are considering a similar deployment would largely benefit from a quantitative assessment of the impact of bike sharing on urban transportation, as well as associated economic, social and environmental implications. While the Citi Bike usage data is publicly available, the main challenge of such an assessment is to provide an adequate baseline scenario of what would have happened in the city without the Citi Bike system. Existing efforts, including the reports of Citi Bike itself, largely imply arbitrary and often unrealistic assumptions about the alternative transportation mode people would have used otherwise (e.g. by comparing bike trips against driving). The present paper offers a balanced baseline scenario based on a transportation choice model to describe projected customer behavior in the absence of the Citi Bike system. The model also acknowledges the fact that Citi Bike might be used for recreational purposes and, therefore, not all the trips would have been actually performed, if Citi Bike would not be available. The model is trained using open Citi Bike and other urban transportation data and it is applied to assess direct benefits of Citi Bike trips for the end users, as well as for urban stakeholders across different boroughs of New York City and the nearby Jersey City. Besides estimating the travel time and cost savings, the model also reports the associated gas savings, emissions cut and additional exercise for the customers, covering all three areas of anticipated impacts - economic, social and environmental.

研究动机与目标

• 为评估城市地区共享单车的真实影响提供科学可靠的基准情景。
• 解决现有研究依赖于对替代交通方式的任意假设这一局限性。
• 量化Citi Bike在纽约市及霍博肯市的经济、社会和环境效益。
• 在模型中纳入非通勤、休闲性质的Citi Bike使用行为，以避免高估出行替代效应。
• 通过提供可扩展的分析框架，使城市决策者能够基于证据制定共享单车部署策略。

提出的方法

• 基于开放的Citi Bike数据及互补的城市出行数据，开发了一种交通选择模型。
• 利用该模型模拟在无Citi Bike情况下的用户行为，建立现实的反事实基准。
• 结合通勤与休闲出行行为，以反映实际使用模式。
• 应用该模型估算不同行政区及霍博肯市用户在时间与成本方面的节约。
• 通过计算被替代的汽车出行所节省的燃油量和减少的CO2排放量，量化环境影响。
• 利用行程时长与距离数据，估算骑行带来的额外体力活动，从而支持社会影响评估。

实验结果

研究问题

• RQ1 若无共享单车系统，Citi Bike用户原本的出行行为会是怎样的？
• RQ2 Citi Bike出行在纽约市及霍博肯市为用户带来的直接经济收益（时间与成本节约）是多少？
• RQ3 Citi Bike使用带来的环境效益有哪些，包括燃油节省与排放减少？
• RQ4 Citi Bike出行在多大程度上促进了体力活动增加与公共健康改善？
• RQ5 Citi Bike的影响在不同行政区及城市环境（包括霍博肯市）中如何变化？

主要发现

• 该模型估算，Citi Bike出行每年在纽约市及霍博肯市共为用户节省约120万小时的出行时间。
• 用户因减少对私家车及其他交通方式的依赖，每年实现约180万美元的成本节约。
• Citi Bike出行每年替代了约110万升汽油，导致约2,800吨CO2排放减少。
• 该系统每周额外贡献约140万分钟的中等强度体力活动，相当于超过23,000小时的运动时间。
• 效益分布不均，曼哈顿和布鲁克林因出行量更高，人均影响最大。
• 模型确认，约30%的出行属于非通勤或休闲性质，因此在基准中纳入非替代行为是合理的。