Impact of regional driving behavior differences on traffic flow

Cross-border driving can lead to differences in driving behavior due to factors such as driving regulations and vehicle configurations, which subsequently impact traffic efficiency and safety. Approximately 69% of countries and regions worldwide follow right-hand traffic (RHT) rules and use left-hand drive (LHD) vehicles, while the remainder follow left-hand traffic (LHT) rules and use right-hand drive (RHD) vehicles. Cross-border driving creates a mixed-traffic scenario involving both LHD and RHD. However, the differences in driving behavior between these two vehicle types and their impacts on traffic flow characteristics remain poorly understood. Here, we show that by utilizing license plate recognition data from the Guangdong-Hong Kong-Macao Greater Bay Area, we have developed an integrated macroscopic and microscopic traffic analysis framework. This framework allows us to analyze individual-level driving behavior differences and quantify their effects on overall traffic performance under both real-world and simulated conditions. Our findings reveal that RHD and LHD vehicles exhibit distinct driving behavior patterns, and these differences persist in the long term. The coexistence of RHD and LHD vehicles can reduce road capacity by approximately 15%. Thus, managing mixed traffic requires attention to behavioral differences and the penetration rates of heterogeneous vehicles.