System and methods are provided for warning a worker of a rail vehicle, or an operator of the rail vehicle of the worker. The system includes a worker device, a vehicle device, and a central server. The devices and server operate on one or a combination of actual or simulated satellite navigational signals, and beacon signals to determine the position of the devices, to generate a warning. The position determination may prioritize beacon signals over satellite navigation signals. The position determination may involve correcting a calculated position based on a measured power level of the beacon signal received from the beacon transmitter, an elapsed time since a previous beacon signal was last received by the device from the beacon transmitter, an elapsed time since a previous satellite navigation signal was received by the device, or an accuracy of the position of the device based on the satellite navigation signal.