|M.Sc Student||Namouz Adell|
|Subject||Investigation of the Impact of Speed Limiters on Driver's|
Behavior and Freeway Safety Level
|Department||Department of Civil and Environmental Engineering||Supervisor||Professor Emeritus Avishai Ceder|
This research investigates what would have happened if
installing speed limiter on all vehicles in the traffic stream except emergency
cars. The research's objectives are three-fold: (a) to examine and analyze the expected changes in the traffic-speed
distribution following the installation of speed limiters on all, except
emergency, vehicles at different speed-restriction values. (b) To investigate
and estimate the expected changes both in drivers’ behavior and road- safety
levels following the installation of speed limiters. (c) To examine the relationship between the percentages of
buses and trucks equipped with speed limiters and their fatal road accident
involvement rates at freeways and highways in Israel.
A model was developed to evaluate the expected changes in traffic speed distribution, the evaluation process uses a simulation model, VISSIM, and in addition five road-safety risk indexes were identified for evaluating the safety level before and after the introduction of the speed limiter. Research's findings indicate significant expected improvement in the road safety level with the use of speed limiters. It is based mainly on the three conclusions: (a) Larger headways between following vehicles, thus providing drivers more time to react to unexpected events (correlated with the expected reduction in rear-end collisions). (b) Less lane changing and a reduction in overtaking situations, resulting in a smaller number of vehicles and road conflicts. (c) The increase in the percentage of vehicles with speed limiters reduces the fatal accident involvement rate.