Some states in the US have laws regulating the brightness of billboards and how frequently they are allowed to change the image on them if they're visible from a highway. Of course, that requires someone to enforce the law, and the billboard lobby is one of the most effective at getting their way.
I've traveled to Hawaii (specifically the Big Island) several times and drove H19 countless times between Kailua-Kona and Waikoloa. For about 30 minutes you are driving through old lava fields with a view of the ocean, some goats and the other cars on the road. I've never realized the lack of billboards and I thank those responsible for that. I can imagine that drive inundated with billboards if it was allowed. Trying to sell sunset cruises, sunscreen and your next time share.
