"Business district" means the territory contiguous to and including a highway when within any six hundred feet (600') along such highway there are buildings in use for business or industrial purposes, including, but not limited to, hotels, banks or office buildings, railroad stations and public buildings which occupy at least three hundred feet (300') of frontage on one side or three hundred feet (300') collectively on both sides of the highway. (Ord. 43 §1(e), 1966)