1) Citizens of cities/towns have the right to a livable town. That includes asthetics, the ability to see the street signs hidden behind advertisements, etc.
2) Businesses have the right to advertise their business.
Most people take the idea that they should ban one right to help the other right. Either they want to hurt people and help businesses or they want to help people and hurt businesses. I say make a compromise.
A) Have a code that applies to all buisnesses, a code that allows them a small number of descriptive ads for their business.
B) What about businesses that need/want more than the simple code? Allow that too, but at a reasonable monthly tax. A tax high enough that the clutter will be removed. A tax low enough that businesses can still advertise as they need.
C) Heck with your competitors only using 3 billboards within 100 feet of their business, maybe you don't need your 10 billboards in that area. Cutting back may even make your business MORE visible.
D) Give that tax money right back to the customers/businesses with tax cuts elsewhere.