北京地铁18号线空载试运行，有望年底开通，线路走向首次明确

Core Viewpoint - Beijing's Metro Line 18 has officially commenced empty test operations, with plans to open by the end of the year, enhancing connectivity in the northern urban areas of Haidian and Changping [1][4]. Group 1: Line Specifications - Metro Line 18 spans a total length of 20.8 kilometers, serving as a key east-west route in northern Beijing [3]. - The line is designed to improve commuting efficiency and has been renamed from a part of the Line 13 expansion project to enhance its recognition [3]. Group 2: Technical Features - The newly deployed trains are the lightest in Beijing's metro system, featuring a maximum capacity of 2016 passengers and a top speed of 80 km/h, which is approximately 12 tons lighter than existing Line 13 trains, significantly reducing energy consumption [3]. - The trains are equipped with advanced passenger comfort and safety features, including a 100 mm higher ceiling for spaciousness, improved air conditioning for uniform airflow, and the first use of carbon fiber electric heating seats in China [3]. Group 3: Operational Readiness - The empty test operations mark a critical transition from construction to passenger service, with ongoing safety assessments and preparations for initial operations [4]. - Once operational, Line 18 will enhance connections between major residential areas in northern Haidian and employment hubs like Zhongguancun Software Park, significantly reducing travel times and improving public transport service levels [4].