The bridge and elevated highway protection system includes two parts: 1. Rotating guardrails, which have anti-collision energy absorption and dissipation effects, can improve safety and reduce the occurrence and severity of accidents. 2. High-speed overload detection and alarm devices for highways and bridges based on piezoelectric sensors. Both items are at the leading level domestically. The first item has been tested by the Ministry of Transport's Engineering Quality Inspection Center and is now mass-produced and applied on highways. The long-term goal is to integrate this product into an intelligent inspection and monitoring system for bridges and elevated highways, including anti-collision guardrails, overload detection alarms, defect and crack detection early warnings, stress detection early warnings, etc., becoming a part of intelligent transportation. The national market capacity for this product is over 2 billion yuan. Currently, it has been promoted to eleven provinces and cities, such as Zhejiang where it has been widely used. In 2016, it achieved a production value of 3 million yuan, and in 2017, it could achieve a production value of more than 12 million yuan. It has been gradually promoted across the country.