Dynamic Modelling of the Effects of Combined Horizontal and Vertical Curves on Side Friction Factor and Lateral Acceleration

In this study, multiple simulations were conducted using CarSim and TruckSim dynamic simulation software, along with SPSS software for statistical analysis. The simulations were conducted on different types of vehicles: a sedan, SUV, and truck. Speed, delta, grade, and position (location of horizontal and vertical curves relative to each other) were the parameters considered in the simulations. According to the results, a sedan and SUV experience more side friction than a truck in the beginning and at the quarter of the vertical curve. The side friction factors in critical situations are higher than the values in AASHTO 2011. A truck is more likely to roll over because of its high lateral acceleration. The statistical analysis showed that the grade and position did not affect the side friction factor for the sedan and SUV, and could thus be neglected. The results of this study could influence the design of safer roadways.