基于浮动车数据的城市道路通行能力时空特征分析

针对城市道路通行能力定量度量指标,提出基于浮动车数据的道路基本通行能力评估方法;以道路通行能力指标来分析深圳市道路网通行能力的时空分异规律,结论如下：城市道路通行能力具有明显的时变特征和空间分布的不均衡性;各行政区域通行能力在工作日变化平缓,在休息日出现午高峰;通行能力余量无论在工作日和休息日都浮动较大,并在休息日中午显著下降;道路通行能力具有明显区域分类现象,人口密度和发展程度较高区域的道路通行能力整体较低,且一天内的变化较小;道路等级对通行能力和通行能力余量影响显著,较高等级道路一天内变化较大,低等级道路则较平稳。

A Spatio-temporal Analysis on the Heterogeneous Distribution of Urban Road Network Capacity Based on Floating Car Data

The spatio-temporal distribution of road network transportation capacity in Shenzhen City was analyzed based on floating car data. The raw floating car data was pre-processed before it was matched to the exact road. Then, the trajectory of each floating car was rebuilt. This paper calculated the travel speed of all different types of road in different time periods. Meanwhile, a new urban road capacity indicator was proposed, by which the road capacity was directly derived from the travel speed. Taking consideration of various traffic conditions and interactions between vehicles, the indices used to describe lane reduction and lane width reduction were applied to adjust the road capacity. The influence of intersections on road capacity can be ignored when taking the traffic flow as a continuous flow. Time-varying characteristics and heterogeneous spatial distribution was found in the urban road capacity. The trend of hourly road capacity was significantly different between weekdays and weekends. Road capacity kept stable in weekdays until it revealed a peak that appeared at noon in weekends. Reserve capacity changed greatly in both weekdays and weekends. And it decreased significantly at noon in weekends. The road capacity varied dramatically within different districts of the city: the road capacity in Yantian District and Nanshan District were both high, and they shared similar trends, while the road capacity in Longgang District and Bao'an District, which also shared similar trends, were in the average level of the capacity within the city, and slightly lower than the former two districts. Additionally, the road capacity of Futian District and Luohu District were in the lower level of the city. We also found that the urban road capacity was overall evidently low in the areas with higher population density and higher development level, and didn’t change much during the day. Road grade had significant influence on the road capacity and reserve capacity. For higher grade of the urban roads in Shenzhen, the capacity and the reserve capacity varied obviously with time, however there was little change in reserve capacity for lower level of the urban roads.