One of the main difficulties in my country's current road traffic safety contradictions is that drivers on the road cannot obtain road traffic and environmental information at the location ahead as soon as possible, so they cannot make accident risk avoidance behaviors such as slowing down and changing lanes beforehand. To this end, there is an urgent need to develop and innovate a complete set of key technologies for proactive traffic safety early warning through seamless and high-precision positioning of urban vehicles. With the support of projects such as the National 863 Plan, the National Natural Science Foundation of China and the National Science and Technology Support Plan, and after 12 years of joint research by industry, academia and research, this project has broken through online location services for active traffic safety warning of vehicles and seamless high-precision positioning technology for vehicles in the road area., developed Beidou high-precision positioning vehicle-mounted terminal with independent intellectual property rights and a high-precision lane level road map generation system. It effectively supports the construction of an urban active traffic safety early warning and guarantee system based on high-precision location services and reduces the incidence of road traffic accidents. The main innovative achievements of the project: (1) An active traffic safety model based on high-precision location was constructed, and an indicator system for active traffic safety online location services was proposed. For the first time, basic research on an active traffic safety early warning model based on high-precision positioning has been systematically carried out, and a real-time early warning model based on high-precision location coupling driving behavior status and accident causes, a real-time traffic conflict risk assessment and early warning model, and sudden traffic accidents The early warning model has built a set of active traffic safety online location service indicator system, breaking through the conflict early warning technology of instantaneous driving state of vehicles and the spatio-temporal prediction technology of traffic accidents persisting and dissipating. Large-scale application of intellectual property transformation relying on basic research results has been realized. (2) Developed a seamless navigation and positioning system for satellite navigation, visual navigation and inertial navigation, and independently developed a high-precision Beidou vehicle-connected terminal for active traffic safety. Aiming at the operating environment and sensor loading characteristics of road-area vehicles, we invented a seamless multi-scale positioning and service vulnerability detection technology that integrates satellite navigation, visual navigation and inertial navigation for road-area vehicles, and developed ldquo; Beidou Instant Judgment; vehicle-mounted terminal, realizing wide-area sub-meter level seamless positioning and active traffic safety early warning services of low-cost consumer-grade electronic devices in complex urban environments, and has urban lane-level positioning capabilities, active traffic safety services and traffic violation evidence collection functions. (3) Developed a high-precision lane-level road network movement collection and generation system that supports active traffic safety, and formulated industry specifications for high-precision lane-level road network information collection that serves active traffic safety. A high-precision lane-level road network mobile acquisition system based on a variety of sensors has been developed and implemented, a number of high-precision road map automatic processing and generation technologies have been invented, and a surveying and mapping industry specification for high-precision lane-level road networks suitable for active traffic safety has been formulated. The project has been authorized for 20 invention patents, 5 utility models, 1 appearance patent, 6 invention patents, 29 software copyrights have been authorized, 1 software product has been authorized, and 69 papers have been published, including 37 SCI searches and 3 industry standards have been drafted., forming large-scale promotion and application products such as ldquo; Beidou Instant Judgment rdquo; and ldquo; Yishitong rdquo;. As a result, the number of comprehensive demonstration users in Shanghai City Pudong New District exceeded 260,000. All-weather real-time safety supervision was carried out on 126,000 operating vehicles in Shanghai City, realizing integrated and large-scale promotion and application in Shanghai, Wuhan, Ningbo and other places, and completing the data sharing and docking with Ningbo Public Security Traffic Police Bureau. More than 300,000 units of law enforcement platforms have been signed by the market, and contracts have been signed with more than 10 insurance companies including China and Sunshine Insurance. The implementation of this project has generated direct economic benefits of 213 million yuan, and indirect benefits of 172 million yuan in key user units including Tencent and Baidu. The decrease in traffic accidents in inter-provincial passenger vehicles in Shanghai City has reached 53.95% within 5 years, achieving significant economic and social benefits.