Access to any lot or building in a B-1 District shall be had only from a business street. As used herein, "business street" means a public highway, road, street or thoroughfare entirely within, or abutting on one side upon, a B-1 District and, in either event, not extending into or through any residential district within 300 feet of any part of the lot or building, access to which is in question, and which public highway, road, street or thoroughfare provides or forms part of a route from the boundary line of the Village to the lot or building, access to which is in question, without passing through any residential district of the Village.