Most city codes require that trees when fully grown do not extend into street or utility right of ways. Although you own that land, a right of way limits your use of that area. Street right of ways are located along the street portion of a property and typically are a minimum of 10 feet. This means your trees can’t grow into that 10 foot portion. The same applies to utility lines. So the city or utility can require you to trim your trees if they intrude into a right of way or easement. To avoid problems, plant your trees and shrubs far enough away to anticipate future growth and trim them regularly when mature.