LAUSR

Objective As the most populous city in China, Shanghai has 24.4 million resident population, 6.5 million of whom are motor vehicle drivers. According to the Traffic police, 868 people died due to road traffic crashes in 2016 in Shanghai. Wearing a seatbelt reduces the risk of death in the event of a crash by 50% for front seat occupants and 75% for rear seat occupants. Chinese traffic laws require seatbelt use for all occupants, but difficulty with enforcement has resulted in low compliance rate. Shanghai police started using high-resolution cameras and object-detection algorithm in seatbelt enforcement since early 2016. Our objective is to assess the level and trend of seatbelt use in Shanghai. Methods Data are collected at eight randomly selected locations throughout the city. The sites were picked to allow for a range of road types (elevated and ground, urban and peri-urban, varying speed limits) and geographic locations. Data collection covers most times of the day on both weekday and weekend. This allows a full representation of varying traffic models during both rush hours and non-rush hours. At each site, trained field workers from Shanghai CDC observed seatbelt use of occupants in all passing motor vehicles. Findings We have completed five rounds of data collection with a total sample size of 57 639 drivers and passengers. The seatbelt use rate has been consistently increasing over time, from 60.8% in round 1% to 81.4% in round 5. The increase is substantial and statistically significant for both drivers and passengers. The seatbelt use was more than twice higher among drivers than passengers, but the ratio of driver over passenger wearing rate has been declining, which implies that the passenger use rate is catching up. Females are more likely to wear seatbelt than males. 95.7% of female drivers and 71.2% female passengers use seatbelt, compared to 94.4% for male drivers and 39.6% for male passengers. Conclusion and policy implications Seatbelt use has been boosted by the deployment of computer vision technology in enforcement. Other cities in China and other countries facing similar challenges with seatbelt enforcement may learn from Shanghai’s experience.