  Automated Vehicles are an integral part of Intelligent Transportation Systems
(ITSs) and are expected to play a crucial role in the future mobility services.
This paper investigates two classes of self-driving vehicles: (i) Level 4&5
Automated Vehicles (AVs) that rely solely on their on-board sensors for
environmental perception tasks, and (ii) Connected and Automated Vehicles
(CAVs), leveraging connectivity to further enhance perception via driving
intention and sensor information sharing. Our investigation considers and
quantifies the impact of each vehicle group in large urban road networks in
Europe and in the USA. The key performance metrics are the traffic congestion,
average speed and average trip time. Specifically, the numerical studies show
that the traffic congestion can be reduced by up to a factor of four, while the
average flow speeds of CAV group remains closer to the speed limits and can be
up to 300% greater than the human-driven vehicles. Finally, traffic situations
are also studied, indicating that even a small market penetration of CAVs will
have a substantial net positive effect on the traffic flows.
