  In this paper we consider a kinetic description of follow-the-leader traffic
models, which we use to study the effect of vehicle-wise driver-assist control
strategies at various scales, from that of the local traffic up to that of the
macroscopic stream of vehicles. We provide a theoretical evidence of the fact
that some typical control strategies, such as the alignment of the speeds and
the optimisation of the time headways, impact on the local traffic features
(for instance, the speed and headway dispersion responsible for local traffic
instabilities) but have virtually no effect on the observable macroscopic
traffic trends (for instance, the flux/throughput of vehicles). This unobvious
conclusion, which is in very nice agreement with recent field studies on
autonomous vehicles, suggests that the kinetic approach may be a valid tool for
an organic multiscale investigation and possibly design of driver-assist
algorithms.
