This paper investigates the adaptive ARQ method for turbo coded communication systems in the fast deep fading environment. Different from the traditional ARQ method, this approach provides various throughput for different quality of service (QoS) in the transportation communications. Based on the typical phenomena observed in the turbo coded communication systems under fast deep fading channels, we defined a new parameter to control the ARQ protocol. We also computed the threshold for the new parameter, similar to the BER prediction in EXIT chart. Simulation results demonstrated that the modified ARQ method reduces the bit error rate with less system cost and lower-complexity