四、规划建设4.1城市地下交通4.1.1轨道交通日本地铁十分发达,且公私合营。东京大都市圈拥有世界上覆盖密度最高的轨道交通网络,由近郊铁路、市内铁路和35条地铁组成,日客流超过3 000万人次,客流分担率达86%。东京地铁总长(不含与私营铁路直通运转的路段和副都心线)为292.2公里,共13条路线,每日平均运量近800万人次(图1)。东京轨道线路由于复杂的建设历史而存在公私并立的局面。私营铁路线主要分布在“山手环状线”的外围,连接东京都 Fourth, the planning and construction of 4.1 urban underground transport 4.1.1 Rail Transit Japan Metro is well developed, and public-private partnerships. Tokyo metropolitan area has the world’s most densely populated rail transit network. It consists of suburban railways, city railways and 35 subways. Its daily passenger flow is more than 30 million passengers and its passenger flow share is 86%. The total length of the Tokyo Metro (excluding the straight lines connecting the private railroads and the Fukutoshin Line) is 292.2 kilometers with a total of 13 routes with an average daily traffic of nearly 8 million passengers (Figure 1). Due to the complicated construction history, there is a public-private parallel in Tokyo’s track line. Private railway lines are mainly distributed around the “Yamagata Ring Line”, connecting Tokyo