  Automated driving is now possible in diverse road and traffic conditions.
However, there are still situations that automated vehicles cannot handle
safely and efficiently. In this case, a Transition of Control (ToC) is
necessary so that the driver takes control of the driving. Executing a ToC
requires the driver to get full situation awareness of the driving environment.
If the driver fails to get back the control in a limited time, a Minimum Risk
Maneuver (MRM) is executed to bring the vehicle into a safe state (e.g.,
decelerating to full stop). The execution of ToCs requires some time and can
cause traffic disruption and safety risks that increase if several vehicles
execute ToCs/MRMs at similar times and in the same area. This study proposes to
use novel C-ITS traffic management measures where the infrastructure exploits
V2X communications to assist Connected and Automated Vehicles (CAVs) in the
execution of ToCs. The infrastructure can suggest a spatial distribution of
ToCs, and inform vehicles of the locations where they could execute a safe stop
in case of MRM. This paper reports the first field operational tests that
validate the feasibility and quantify the benefits of the proposed
infrastructure-assisted ToC and MRM management. The paper also presents the CAV
and roadside infrastructure prototypes implemented and used in the trials. The
conducted field trials demonstrate that infrastructure-assisted traffic
management solutions can reduce safety risks and traffic disruptions.
