Weather and Road Geometry Impact on Acceleration Behavior: Experimental Set-Up and Data Collection Using a Driving Simulator

Transportation researchers tried for decades to investigate the dynamics of traffic flow in order to “optimize” the movement of goods and people under different surrounding conditions while reducing the negative environmental impacts and the economic losses due to congestion and traffic incidents. An important aspect missing from some previous studies relates to the activities through which drivers process the information representing a given surrounding. Such activities include: perception, evaluation, judgment and execution. Recognizing such limitation, the objective of this paper is utilize a 3-D driving simulator to advance the state of knowledge related to driving behavior while considering the surrounding environment’s impact (weather and road geometry) on drivers’ decision-making logic. Through a thorough literature review, the authors looked at the external factors that may impact longitudinal driving behavior. The major factors considered include visibility level, road friction, curvature, gradient, median existence, lane width and shoulder width. The literature review is then translated to an experimental set-up with variables that “parameterize” the external environment’s characteristics. A total of 36 students and staff from the George Washington University, 26 male and 10 female, with varying driving experience participated in the experiments. The participants drove behind a yellow cab which speed patterns are dictated by real-word trajectories taken from the NGSIM trajectory data. The collected performance measures include accelerations, speeds, longitudinal and lateral coordinates of the subject vehicle and the lead vehicle.