Cooperative Mainstream Traffic Flow Control on Freeways**The authors were funded by CNPq-Brasil.

Mainstream Traffic Flow Control (MTFC) is a freeway traffic control method which aims to maximize throughput by regulating the mainstream flow upstream from a bottleneck. Using Variable Speed Limits (VSL) as actuators for MTFC, we study the effects of different penetration rates of automated vehicles on MTFC-VSL. Automated vehicles can be designed to be much more strict in complying with VSL, which leads to a better MTFC performance than with ordinary VSL. Simulation results show that higher penetration rates translate into better performance with a significant effect up to 30% penetration rate, and very little gains beyond that; and that mixing forms of applying VSL may be detrimental to traffic.