北京公交就业可达性及其地区和人群差异

运用经济普查、人口普查数据和基于百度地图的公交出行时间数据,分析北京都市区基于公共交通的就业可达性及其在城市不同人群和地区间的差异。结果表明：北京都市区的居民可在60分钟内通过公共交通到达18.3%的都市区工作岗位,这比美国100个最大的都市区的平均就业可达性水平要高,接近于美国纽约都市区的就业可达性水平。同时,由于就业郊区化程度有限和以中心—放射式布局的公交网络,北京都市区内的公交就业可达性存在着巨大的区域差异,中心城区的就业可达性远远高于郊区。此外,人口居住的郊区化程度远远高于就业的郊区化程度,导致北京都市区宏观层面的职住不平衡。随着人口居住郊区化程度的提高,公共交通如何服务居住日益分散的人口,提高就业可达性,是一项巨大的挑战。研究还发现,由于城市中心区的大部分就业为高技术的就业岗位,因此高受教育程度人口能更多地享受目前公共交通系统的便利,而受教育程度低的人口和外来人口公交就业可达性较低。为解决弱势群体所面临的就业可达性的不平等问题,需要更多的规划与政策干预。

Job accessibility by transit and variation among different population groups and in different regions in Beijing

Using the latest economic census and population census data as well as the transit-based travel time data obtained through the Baidu Map API, this study examines the job accessibility via transit in the Beijing metropolitan area and helps understand how well workers can access jobs by transit in Beijing and how it is different for various population groups and in different regions. Our results show that residents in the Beijing metropolitan area can reach 18.3% of metropolitan jobs within 60 minutes by transit, which is better than the average job accessibility via transit for 100 largest metropolitan areas in the United States, and similar to the New York metropolitan area. Due to the limited extent of job suburbanization as well as the hub-and-spoke pattern of the road and transit network in Beijing, there exist great regional disparities in the job accessibility by transit within the Beijing metropolitan area, with the job accessibility level significantly higher in the inner city than in the suburbs. Compared to jobs, population has suburbanized more extensively in Beijing, which has led to the great jobs-housing imbalance in the metropolitan area. With the increasingly more extensively decentralized spatial distribution of population, great challenges lie in further expanding the transit network to better serve the suburbs. Meanwhile, since most jobs in the inner city are oriented toward workers with higher levels of education, highly educated population is better served by the current transit system. Meanwhile, less educated population (without college degrees) and migrants reach less metropolitan jobs by transit because they are more extensively suburbanized due to their relatively low income and limited housing options. This raises a concern about the ability of suburbanizing disadvantaged populations to connect to job opportunities via transit. Therefore, multiple policies including affordable housing programs, transit investments, economic development initiatives, and appropriate land use planning should be coordinated to address the apparent spatial mismatch that disadvantaged population groups are facing.