An enhanced mobile communication device communicates directly with other enhanced mobile communication devices in an ad-hoc mode over a wireless medium. The device transmits and receives packets of digital data. The packets of digital data are such that when transmitted, the probability that they will be received by the other mobile communication devices is increased. The probability is further increased by transmitting the packets a multiple and variable number of times according activity in the wireless medium. Attempts to transmit are made periodically and the period of transmission is adjusted according to activity in the wireless medium. In a transportation application, the packets comprise vehicle traffic congestion update information. The device maintains a traffic database and a map database. Traffic congestion update information is exchanged with other devices. Routes through the map from a source or current position of the device to a destination are computed according to an analysis of the traffic database.