For the purposes of this act, a limited access highway is defined as a public highway to which owners or occupants of abutting property or the traveling public have no right of ingress or egress to, from or across such highway, except as may be provided by the authorities responsible therefor. A local service highway is defined as a public highway, either existing, or new, or combination thereof, parallel or approximately parallel to the limited access highway which will provide ingress or egress to or from highways or areas which would otherwise be isolated by the construction or establishment of a limited access highway.