When it comes to billboards, I want to give a little shout-out to the Washington State, which I think has a rather clever and effective rule: Advertisements along the highway have to be for things people can actually get on the property hosting the sign. [0]

This prevents pathological billboards in a rather organic way: Real businesses don't have enough financial incentive to blot out the sky above, or create a chain of self-competing active sites, and anyone who does erect a forest of billboards will have a hard time inventing a profitable business underneath to buy the space. [1]

[0] https://app.leg.wa.gov/rcw/default.aspx?cite=47.42

[1] I anticipate this will need adjustment as someone tries to argue a tiny touchpad kiosk at the base of the billboard tower counts when remotely ordering a product for future delivery elsewhere.

Time to put a mini server rack under every billboard, so the property is serving up whatever digital offering the billboard advertises.