1. A follower controller module adapted for mounting on board a locomotive, said follower controller module comprising a processing module operative for: a) receiving a signal indicative of a spoken utterance; b) generating in response to the signal received in a) data indicative of a command to be executed by the locomotive; c) said follower controller module being responsive to the data indicative of a command to be executed by the locomotive for generating local control signals for issuing to the locomotive so as to cause the locomotive to execute the command.