Vehicular Ad-hoc Networks (VANETs) utilize mobile vehicles to provide edge computing for safety applications. Safety related messages dissemination in VANETs is quite significant. Effective safety related messages broadcast protocols are proposed based on a priori assumption that all vehicles have the same communication radius. In this article we focus on highway scenarios, and put forward a novel safety related messages broadcast protocol based on Non-Redundant Communication Range(NRCR, for short), that can handle safety related messages multi-hop broadcast in non-isomeric vehicular communication radius scenario, namely heterogeneous VANETs topology. The NRCR-CAST protocol we proposed is a distributed broadcast protocol that relies on local topology information for disseminating safety related messages both in dense and spare VANETs scenarios. It is shown that the proposed NRCR-CAST protocol performs well in terms of packet receive ratio, packet end-to-end delay and network overhead.