טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentNamouz Adell
SubjectInvestigation of the Impact of Speed Limiters on Driver's
Behavior and Freeway Safety Level
DepartmentDepartment of Civil and Environmental Engineering
Supervisor Professor Emeritus Avishai Ceder


Abstract

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.