For the purpose of this chapter, a controlled-access facility is defined as a highway or portion of a highway especially designed for through traffic, and over, from, or to which owners or occupants of abutting land or other persons have no right or only a controlled right or easement of access, light, air, or view by reason of the fact that their property abuts upon such controlled-access facility or for any other reason. Such highways may be freeways open to use by all customary forms of highway traffic; or they may be parkways from which trucks, buses, and other commercial vehicles shall be excluded.