The First “Digital Twin Sea-Crossing Bridge” of China
The bridge command center goes digital.
Photo by Fan Hong
Traffic control plans can be implemented within seconds to warn drivers of an accident ahead; detailed traffic flows can be displayed on digital screens to broadcast real-time traffic information on the bridge. Hangzhou Bay Bridge has been a pioneer in remapping all-weather roads with vision-based digital twin technology, rendering it China’s first “digital twin sea-crossing bridge”.
As the journalists from Ningbo Evening News walked into the command center, a large screen with a virtual Hangzhou Bay Bridge on it came into view. Real-time data, incidents and images, the BeiDou Navigation Satellite System, traffic congestion, and response work on the bridge were all displayed. The comprehensive and dynamic information assessment means that any changes to the traffic environment are updated and digitally analyzed to implement adaptive traffic management plans.
Along the bridge, digital high-definition cameras with AI are spaced 125 meters in an orderly manner, each of which monitors both lanes, guaranteeing full coverage of the traffic conditions.
Digital Twin is a simulation technology that integrates multidisciplinary, multi-physical quantity, multi-scale and multi-probability through fully analyzing physical models, sensors, operating history and other data to realize mapping in the cloud or meta-universe, which then digitally reflects the whole life cycle of the physical object. Therefore, it can be interpreted as building a “twin bridge” synchronized with the physical bridge in a replicated virtual environment.
Based on this technology, a digital model of the Hangzhou Bay Bridge has been built to monitor and update the dynamics of traffic, including real-time traffic flow, infrastructure and other road conditions. 108 strategies for 18 types of accidents across the bridge are thus in place. For example: What is the exact location of the rear-end collision? Are emergency assistance and temporary lane closure required? How many lanes are occupied because of the accident? How should the vehicles behind avoid the crashed vehicles?
How are traffic alerts and predictions conveyed to vehicles and passengers on the bridge, then? Hangzhou Bay Bridge provides full coverage of accurate traffic guidance services. Smart devices including 1,828 sets of intelligent fog lights, 40 full-color screens, and 346 sets of directional digital early warning broadcast equipment make it possible to complete news-producing processes within 10 seconds, allowing passengers to access accurate and timely information about road conditions.
Every 2 seconds, a car drives over the Hangzhou Bay Bridge. It serves as a highway bridge connecting the eastern coast of Zhejiang province to Shanghai, as well as Suzhou, Wuxi and Changzhou in Jiangsu province, saving 15 billion yuan in the social costs of energy consumption.
Zhu Mei, deputy general manager of Ningbo Communications Investment Holdings Co., Ltd. and president of Ningbo Hangzhou Bay Bridge Development Co., Ltd., praised digital transformation of the bridge. In the first half of 2022, the accident rate dropped by 16.4% year on year, and the secondary accident rate decreased by 66% year on year. Meanwhile, 99% of incidents can be detected with rescue forces arriving at the scene within 20 minutes. Hangzhou Bay Bridge, which opened to traffic nearly 15 years ago, has embarked on a new journey of digitalization.