I feel like given the danger these vehicles represent that their location should be published publicly so that humans can avoid the highway when they are near and possibly plan alternative routes.
Also, I believe that part of the "plan" is to eventually once the technology hits it limit of effectiveness (cant get any better but is still deadly), flood the highways with enough of them and autonomous cars to scare humans off the roads. There will be a tipping point where humans wont feel safe driving on the roads with these vehicles in large enough numbers (because they arent).
At that point we will be paying taxes for robot highways, and to fund liability protections for tech companies.