What a horrible waste of work that would be. In the sense that the energy and time taken from other road uses just for a little advertising would be obnoxious.
Adverts only continue to exist because they ultimately find the sweetspot between inconvenience and payoff. A road mobile billboard is inconveniencing everyone and the payoff is nil. In contrast to a YouTube advert where the payoff is the youtube video, a mobile billboard has no payoff.
So like the trucks going up and down the Las Vegas strip, but hundreds and hundreds of them . Moving billboards everywhere. Unintended consequences indeed.
I wonder how many other possible unintended consequences there will be