北京市小汽车通勤可达性变化及驱动因素分析

城市空间结构演化与交通发展之间存在动态互馈关系，可达性是连接二者的 关键纽带.基于潜能模型，在1 km × 1 km网格尺度上，计算了2000 年和2010 年北京市小 汽车的通勤可达性，并利用敏感性分析的思路研究通勤可达性变化的驱动因素.结果表 明，小汽车通勤可达性的时间变化体现为10 年间大幅提高，增长54%；空间上由中心区向 外围可达性递减的分布格局保持不变，但2010 年的可达性沿环路及高速公路蔓延的现 象更加明显，而且不同区域可达性变化的绝对值及变化率具有显著差异. 城市空间结构 变化对小汽车通勤可达性具有主要提升作用，但部分提升作用被路网运行速度的降低效 果所抵消.促进交通基础设施建设与城市空间布局的协调，仍是未来研究的重要课题.

Analyzing the Change of Commuting Accessibility by Car and its Driving Forces in Beijing

There is dynamic correlation between urban spatial structure evolution and traffic development, and accessibility is their key link. This paper analyzes the temporal evolution from 2000 to 2010 and driving forces of commuting accessibility by car in Beijing by employing the potential model and sensitivity analysis at 1km × 1km scale. The results show that: in time commuting accessibility by car has been greatly improved by 54%; in space, the spatial distribution of commuting accessibility decreasing from center outward has little change; however, the spreading phenomenon along the ring roads and highways is more obvious in 2010. Moreover, the absolute and relative changes of commuting accessibility in different areas are significantly different. As a whole, changing urban spatial structure plays a positive role in improve commuting accessibility, while some positive effects has been offset by that of decreasing speed of road networks. Therefore, facilitating the coordination between transportation infrastructure and urban spatial structure is still an important topic for future research.