How about drones only fly over public roads when they are below 500 feet?

But why?

If you're concerned about safety, you'd prefer an out-of-control drone hits a car instead of a backyard or farmer's field?

And if you're concerned about noise, homes tend to be along roads anyways. So it's not going to change that.

And FYI, they're basically always below 500 feet, so they don't hit planes.