The present invention involves a digital audio player and a method for processing encoded digital audio data, wherein the digital audio data is encoded using one of a plurality of encoding formats. A secondary station wishing to use a random access channel resource transmits a preamble encoded with a signature corresponding to the required resource. For each vehicle, a set of states, for example position, speed, acceleration, and the like, where a collision is imminent can be identified using state information for a local vehicle, a remote vehicle, and a known collision zone for the intersection.