A first communication device is configured to process packets that conform to a first physical layer (PHY) protocol for wireless vehicular communications and packets that conform to a second PHY protocol for wireless vehicular communications. The first communication device determines that one or more second communication devices neighboring the first communication device are not capable of processing packets that conform to the second PHY protocol. The first communication device transmits a first packet to a third communication device that is configured to process packets that conform to the first PHY protocol and packets that conform to the second PHY protocol. The first packet indicates that the one or more second communication devices neighboring the first communication device are not capable of processing packets that conform to the second PHY protocol to inform the third communication device of the one or more second communication devices.