  We demonstrate a new capability of automated vehicles: mixed autonomy traffic
control. With this new capability, automated vehicles can shape the traffic
flows composed of other non-automated vehicles, which has the promise to
improve safety, efficiency, and energy outcomes in transportation systems at a
societal scale. Investigating mixed autonomy mobile traffic control must be
done in situ given that the complex dynamics of other drivers and their
response to a team of automated vehicles cannot be effectively modeled. This
capability has been blocked because there is no existing scalable and
affordable platform for experimental control. This paper introduces an
extensible open-source hardware and software platform, enabling a team of 100
vehicles to execute several different vehicular control algorithms as a
collaborative fleet, composed of three different makes and models, which drove
22752 miles in a combined 1022 hours, over 5 days in Nashville, TN in November
2022.
