Provided is an operator warning system for use in connection with a locomotive having a horn system with a horn activation actuator and a horn device for producing a noise. The operator warning system includes an onboard computer system with a database having grade crossing data and locomotive data thereon. The onboard computer system is in communication with the horn system. The operator warning system also includes a warning device for providing an audio, visual and/or tactile indicator to an operator of the locomotive based upon the grade crossing data, locomotive data and/or actuation condition of the horn activation actuator. A method for improving locomotive operator vigilance is also provided.