## 2 Literature Review  
Road design codes or guidelines in many developed countries provide recommended lane widths for various road conditions. For example, highway design reference documents in the United States recommend a highway lane width of 12 feet (3.66 m) [9]. According to the German Road and Traffic Research Association, the right-side lane width, which is mainly used by heavy vehicles, should be 3.75 m, while the left-side lane width can be set to 3.5 m [10]. The Canadian Transport Association defines a highway lane width of 3.5 to 3.7 m [11], while the British Highways Agency considers a typical lane width of 3.65 to 3.7 m [12]. Currently, the recommended lane width on China's highways is 3.75 m, but when passenger cars dominate, the lane width can be reduced to 3.50 m [13]. Effective lane width design must balance both road capacity and safety. On the one hand, reducing lane width should not significantly compromise traffic flow efficiency. [PERSON] et al. [14] argue that the Highway Capacity Manual (HCM) guidelines for lane width adjustments are outdated and propose a predictive model to simulate the impact of narrower lanes on traffic flow efficiency. [PERSON] et al. [15] found that, under identical conditions, operating speeds between 12-foot and 11-foot lanes exhibit minimal variation. On the other hand, lane width reduction must prioritize traffic safety. [PERSON] et al. [16] examined the effect of lane width reduction on overall highway safety performance and discovered that left shoulder width has a more significant impact on collision rates compared to lane width. Improving safety levels becomes challenging when lane widths exceed 12 feet. [PERSON] et al. [17] quantified the impact of different lane widths on vehicle collision frequency in various accidents on urban expressways using vehicle collision and traffic flow data. Their results indicated that standard-sized lanes with a width of 3.45 m have the lowest collision risk. Developing an effective lane width calculation model is crucial for the design of lane widths. One common approach is to utilize the Boryankov model to determine appropriate lane widths by controlling lateral safety spacing between vehicles or between vehicles and the curb. Some scholars have utilized data collected from different scenarios to fit different \"speed-distance\" models, in which the terms containing the speed are in the form of primary function, power function, speed difference and squared difference [18]. However, this model considers only the impact of speed. An alternative method involves determining lane width by considering three factors: vehicle width, lateral safety clearance and lateral oscillation of the track [19]. This approach does not account for vehicle interactions. Driving behavior serves as the primary foundation for developing the methodology of lane width calculation. Behaviors such as avoidance, lane change and merging in overtaking scenarios need to be emphasized in lane width design due to their high occupancy of the road cross-section. [PERSON] et al. [20] investigated the effects of the speed of the impeding vehicle, the type of vehicle being overtaken and the passing sight distance on the initial following gap distance. Their results indicated that the speed of the impeding vehicle had a more substantial influence on the initial following gap distance during overtaking maneuvers compared to the type of the impeding vehicle or the passing sight distance. [PERSON] et al. [21] introduced a novel variable, \"excess distance\", to analyze overtaking behavior. The data showed that the rate of change in excess distance is influenced by both road type and characteristics of the overtaking vehicle. [PERSON] et al. [22] developed models for overtaking distance and time under mixed traffic conditions. Their findings revealed that the distance and time required to overtake heavy vehicles are significantly greater than for other types of vehicles. [PERSON] et al.