{'fraction_non_alphanumeric': 0.02138157894736842, 'fraction_numerical': 0.018092105263157895, 'mean_word_length': 4.907766990291262, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
How does rail transit promote the sustainable development of Beijing metropolitan area?

The main objective of the paper is to study how the rail transit system promotes the development of Beijing metropolitan area. The paper finds Beijing is in a critical period to develop metropolitan area and commuter railway by analyzing the evolution of Beijing city spatial structure and rail transit. Then, it analyses how rail transit promote the Beijing metropolitan area from the perspective of stations, lines and network using the “Points-axis” theory by comparing with the Tokyo metropolitan area. Results shows that in the guide of the multi-level rail transit system which includes urban subway as the principal axis within the radius of 0-15km, light railway as the secondary axis within the radius of 15-30km, commuter railway as the tertiary axis within the radius of 30-70km, Beijing metropolitan area in the future, therefore, will form the reasonable spatial structure in which core area within the radius of 0-15km is the center, new cities such as Shunyi, Tongzhou and Daxing within the radius of 15-30km will be sub-centers and satellite towns includes Pinggu, Yanjiao and Guan within the radius of 30-70km.