For each family residing on a lot, there shall be provided adequate space for the parking or garaging of at least two noncommercial motor vehicles; and in connection with an authorized use other than residential, which shall include home occupations, there shall be provided adequate parking facilities for all motor vehicles used in connection therewith or attached to said building or area as specified elsewhere in this chapter or, if not specified, as required by the Planning Commission. The parking, garaging or storing of industrial equipment or commercial vehicles, trailers or semi-trailers having a carrying capacity in excess of one ton or a gross weight in excess of three tons is expressly prohibited. Trucks with a carrying capacity of three tons or less, motor homes, recreational vehicles, utility vehicles, campers and similar vehicles and boats shall be stored in an enclosed building or on that part of the lot where an accessory garage would be permitted by code, or in an existing driveway so as not to impair ability to see oncoming traffic when exiting said driveway.