|M.Sc Student||Hallac Pauliana|
|Subject||The Effects of Adaptive Cruise Control and Cooperative|
Adaptive Cruise Control on Traffic and Safety
|Department||Department of Civil and Environmental Engineering||Supervisor||Professor Tomer Toledo|
|Full Thesis text|
The introduction of automation and connectivity to the transportation sector has attracted the interests of researchers and vehicle manufactures for the past years. It promises to improve road safety and travelers comfort, and give an alternative for people who are unable to drive because of physical, age or other limitations. On the other hand a significant impact on traffic flow and the environment are expected after the deployment of AV and connectivity. Hence, these impacts need to be anticipated and plan accordingly before wide deployment of these technologies.
This research focuses on the cruise systems. These systems assist equipped vehicles to follow other vehicles in a safe and comfortable manner. The Adaptive Cruise Control System (ACC) was developed, in which the speed is automatically adjusted to maintain a safe distance from vehicles ahead. In order to improve the ACC, The Cooperative Adaptive Cruise Control (CACC) is an extension of ACC that adds V2V communication to take advantage of preceding vehicle information about the current situation. The inter-vehicle distance can be reduced and string stability would be improved, which in turn improves the comfort and convenience of the driver.
In this study, the algorithms for ACC and CACC were implemented using an existing microsimulation program (AIMSUN), in a way to adapt it to be able to simulate both human driven vehicles and ACC/CACC equipped vehicles. In order to anticipate the impacts of these technologies, a real life case study was simulated, with the Antwerp ring road as the network and real count data demand from morning peak hour.189 scenarios were built depending on four main factors: ACC& CACC penetration rates, different demands and time gaps. The measures of performance for Traffic flow and safety are extracted.
From the results it could be concluded that the introduction of ACC to the transportation system worsens the network’s performance at all penetration rates, demands and time gaps. On the other hand, the introduction of CACC system has positive impacts on the traffic flow and can improve the network’s performance. In mix flow of ACC and CACC equipped vehicles, the impact depends on the combination of ACC&CACC; as the percent of ACC equipped vehicles increases and the percent of CACC equipped vehicles decreases the performance of the network is worsened. In the contrary when the percent of CACC equipped vehicles increases and the percent of ACC equipped vehicles decreases the performance of the network is improved.
Both ACC & CACC systems were found to perform better in smaller time gaps, and their effect becomes more significant in higher demands.
As for safety, both ACC and CACC were found to improve the safety of the network. This is expected since the main reason of developing these technologies was to improve the safety and comfort of the driver.