Abstract Improving residents' travel efficiency and reducing carbon emissions from travel are the key issues for sustainable development of urban transportation. This study first employed a circuity index to measure the path efficiency of residents' trips based on 2015 survey data in Guangzhou and developed a generalized additive model (GAM) to investigate the relationship between the path efficiency and travel distance for different purposes of trip and different travel modes. On this basis, it further evaluated the time efficiency of different travel modes for each trip. The results showed that there is a complex and nonlinear relationship between the path efficiency and travel distance, which differs between different purposes of trips and different travel modes. In general, trips by non-motorized transport have a lower circuity index and higher path efficiency than those by cars or public transport. Moreover, non-motorized transport is the time-efficiency optimal mode for almost half of the trips, especially for daily shopping trips. However, people prefer to choose public transport on their trips even though public transport is not the time-efficiency optimal mode for these trips. Generally, only about half of the residents chose the time-efficiency optimal mode for their trips. Those who did not choose the time-efficiency optimal mode tended to choose the modes with higher carbon-intensity. The conclusions of this study indicate that for improving travel efficiency and reducing carbon emissions from transport, more efforts should be focused on the non-motorized travel environment and developing relevant policies to encourage more walking and cycling.

中文翻译：

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不同出行方式居民不同目的出行的路径和时间效率——以广州为例

摘要 提高居民出行效率、减少出行碳排放是城市交通可持续发展的关键问题。本研究首先基于广州市 2015 年的调查数据，采用循环指数来衡量居民出行的路径效率，并开发了广义可加模型 (GAM) 来研究不同出行目的和不同出行方式的路径效率与出行距离之间的关系。旅行模式。在此基础上，进一步评估了每次出行不同出行方式的时间效率。结果表明，路径效率与出行距离之间存在复杂的非线性关系，且因出行目的和出行方式不同而存在差异。一般来说，与汽车或公共交通相比，非机动交通出行具有更低的迂回指数和更高的路径效率。此外，非机动交通是近一半出行的时间效率最优模式，尤其是日常购物出行。然而，人们更愿意在他们的旅行中选择公共交通工具，即使公共交通工具不是这些旅行的时间效率最佳模式。一般来说，只有大约一半的居民选择了时间效率最优的出行方式。那些没有选择时间效率最优模式的人倾向于选择碳强度较高的模式。本研究的结论表明，为了提高出行效率和减少交通碳排放，