Core Viewpoint - The construction of the Line 1 branch is essential for enhancing the transportation network in the southwestern part of the city, with temporary station closures necessary to facilitate this development [1][2]. Group 1: Project Overview - The Line 1 branch project spans 21 kilometers, connecting Qinglonghu East Station to Bajiao Amusement Park Station, with 17.1 kilometers in Fengtai District and 3.9 kilometers in Shijingshan District [1]. - The project includes the construction of 9 new stations and the renovation of 1 existing station (Bajiao Amusement Park Station), with an average station spacing of 2.3 kilometers [1]. - The branch will integrate with several existing and planned transit lines, including the suburban railway city sub-center line, Line 14, and Line 11, creating a comprehensive transportation service system [2]. Group 2: Construction Details - The construction involves two main components: the renovation of Bajiao Amusement Park Station and the connection works for the branch line [2]. - The renovation of Bajiao Amusement Park Station will create a two-level island station with 4 entrances and 2 pedestrian over-track passages, necessitating the temporary closure of the existing station [2]. - As of now, all 18 construction sites for the Line 1 branch, including 10 stations and 1 parking lot, have commenced work, with significant progress reported: 86% completion of station structures, 27% of section structures, and 70% of vehicle base structures [3].