Technicians patrol inside the emergency access of a shield tunnel along the east sixth ring road in Beijing, capital of China, April 20, 2025. A renovation project on Beijing's east sixth ring road was opened to traffic upon full completion on Sunday. The renovated section is about 16.3 kilometers in length, including a 7.4-kilometer-long shield tunnel. The project helps improve expressway transport across the core area of Beijing's sub-center Tongzhou District. (China Railway 14th Bureau Group Co., Ltd./Handout via Xinhua)