同日多地多条轨道交通新线开通运营 为城市空间拓展和功能优化注入新动力

Group 1 - The core viewpoint of the articles highlights the acceleration of urban rail transit construction in multiple cities, enhancing urban capacity and functionality [1] Group 2 - On December 27, three new subway lines were put into trial operation in Beijing: Line 18, the middle section of Line 17, and the southern extension of Line 6 [5] - Line 18 is a key east-west route in northern Beijing, approximately 19.8 kilometers long with 11 stations, including 4 transfer stations [5] - The middle section of Line 17 is a major north-south transit line in Beijing, measuring 8.2 kilometers with 4 stations, including 2 transfer stations [5] - The southern extension of Line 6 opened the Luyang Station, enhancing connectivity between Tongzhou District and the city center [5] Group 3 - In Jinan, Shandong, three subway lines—Line 4, Line 8, and the eastern section of Line 6—also commenced operations on December 27 [6] - These three lines in Jinan are all oriented east-west, covering a total length of approximately 85.1 kilometers with 64 stations [8]