Amirhosein Karbasi - Master Student, Tarbiat Modares University
Mahmoud Saffarzadeh - Full Professor, Tarbiat Modares University

The use of autonomous vehicles (AV) on the roads is becoming areality and these vehicles will change many aspects of transportation.soit is necessary to research the impact of this kind of vehicle on differentaspects of transportation. On the other hand, two aspects of this kind ofvehicle can pose important challenges for researchers. The first aspectis automation.so, the impact of the automation aspect of these vehiclesand different levels of automation should be investigated. Second, theaspect is the connectivity that should be taken into account.in this studywith the help of microsimulation and macroscopic fundamental diagram(MFD) and considering these two important aspects the capacity of asingle roundabout determined. We used the intelligent driver model(IDM) car-following model for specifying driver behavior .then, weused two different speed-density relationship models and traditionalmacroscopic relationships to determine the capacity of roundaboutunder different penetration rates. The results show connected andautomated vehicles (CAV) can improve the capacity of the roundabout.Also, these vehicles can improve the critical density of roundabout.

connected and automated vehicles, Capacity, Roundabout, IDM