A highway that has full or partial access control, is usually located within a park or a ribbon of park-like developments, and prohibits commercial vehicles. Buses are not considered commercial vehicles in this case. (FHWA2)
A parkway is a general designation of a type of limited-access highway in some parts of the U.S. and Canada. (In other parts of the U.S., the term parkway may merely be another title for a normal surface street.) Like all limited-access highways, parkways are designed particularly for through traffic, and many can be classified generally as freeways or toll highways.