Effect of Car/Truck Differential Speed Limits on Two-lane Highways Safety Operation Using Microscopic Simulation

The safety implications of car-truck speed limits have not been adequately researched for two-lane highways. On two-lane highways speed controls can have a significant effect on vehicles interactions. Two different types of speed control strategies are considered: Uniform and Differential. Safety implications are considered using three overtaking-related indicators: Number of vehicles overtaking, 2) Percentage time spent in “desire to overtake mode”, and 3) Average Time-to-Collision with the on-coming vehicle prior to returning to the original lane. Vehicle interactions affecting safety are estimated through the application of a calibrated microscopic traffic simulation model to a 6Km straight segment of two-lane highway.