I have thought it through very well, and my logic is consistent. Acceptible or not depends on 1) if it is useful in the situation (traffic signs are, for driver safety; advertising isn't) 2) whether the receiver can block the ad with technology (not yet possible on road with advertising). You can ridicule me all you want. 33% of all internet users decided to use an ad blocker. They do not want to get distracted by silly skyscrapers, popups, flashy sounds, large irrelevant banners, and so on and so forth.