There was a "documentary" of these guys when they were testing via a hardwire to the car's computers. They were also in the car with the driver as well as in a parking lot and on some non-busy country road.

I wonder if the reporter just added in those details about the highway to make it seem like more of a real threat or if they actually did test on a busy public roadway.

edit: Found the video - https://www.youtube.com/watch?v=oqe6S6m73Zw