Effective lane width for cars considering lateral oscillation characteristics based on high-precision field data

The cross-sectional width of highways is a major factor that affects the construction cost of engineering projects. With the increasing demand for intensive highway construction, research on dedicated lanes or roadway for cars has attracted research attention. The lateral oscillation value of vehicle's trajectory is the direct factor that affects lane width; however, relevant research is relatively limited, and the characteristics are not yet clear. Therefore, this study utilized an integrated radar–video system to collect real high-precision trajectory data, obtaining 24,697 datasets. Statistical methods were used to reveal the lateral oscillation value and determine the effective lane width of car for safe driving. The research results are as follows: 1. The lateral oscillation value of car present differences on different lanes. Vehicles on the inner two lanes tend to drift leftward, whereas those on the outermost lane drift rightward. 2. When operating speed ranges from 80 km/h to 110 km/h, the lateral oscillation value presents a statistical rule, which obeys a normal distribution for the left and right margins, namely, Dleft ∼ N(0.87, 0.15) and Dright ∼ N(0.72, 0.15). This lateral oscillation value is insensitive to fluctuations in operating speed (80 km/h ∼ 110 km/h) from the standpoint of field data. 3. The fitted expressions of effective lane width for cars was proposed and the effective lane width at the 95th, 90th, and 85th percentile is 3.2 m, 3.0 m, and 2.8 m, respectively. These results can provide technical support for dedicated lane width for cars and have practical significance for the intensive construction of road infrastructure in highly urbanized areas. © 2023 Tongji University and Tongji University Press.