A brake monitoring system for use on a motor vehicle includes a sensor connected to each brake actuator shaft on the motor vehicle for monitoring the position and travel of the brake actuator shaft and for generating and transmitting a brake condition signal; a data processor carried in an axle box associated with each axle and connected to sensors associated with brakes for the axle for receiving, interpreting, storing, and upon request, transmitting the brake condition signal, wherein each data processor includes an auto-address mechanism to identify its position on the vehicle; and a master station, wherein said master station includes a display for identifying a particular vehicle brake, a quantitative indication of the travel on the brake actuator shaft associated with the particular brake, and wherein said visual indicating devices include plural indicia which are indicative of said safety condition of a particular brake.