parking lot landscaping

Is there a difference in the landscaping of parking lots regulations between Chapel Hill and Carrboro? I noticed the new lot by the Open Eye Cafe doesn't have any space for trees and the old farmers market (now private carr mill employee parking) only has only one tree handing on. Of course the trees provide pleasant shade in the summer and most people with a car want to park it in the shade. I see some new bus shelters have been built. Is there any plan to plant trees near them?

Loren