A method for correcting traffic signal state predictions comprising the steps of: accessing a data store of traffic signal timing plans associated with a target traffic signal; accessing a data store of traffic signal schedules used for selecting one at a time of the traffic signal timing plans associated with the target traffic signal; based on a current date-time stamp and the traffic signal schedules, identifying one of the traffic signal timing plans as a currently selected timing plan; acquiring a preliminary prediction of a state change of the target traffic signal, the preliminary prediction based on the currently selected timing plan; identifying a traffic signal controller associated with the target traffic signal; acquiring traffic signal variation data for the traffic signal controller associated with the target traffic signal, comprising: generating baseline predictions for selected state change events of the traffic signal controller based on the traffic signal timing plans and corresponding timing plan schedules; monitoring real-time state change events of the traffic signal controller, and recording the events along with corresponding timestamps; comparing a timestamp of a baseline prediction to a timestamp of a corresponding one of the real-time state change events to determine a deviation datum for the state change event; and repeating the comparing step for additional real-time state change events to form the traffic signal variation data for the traffic signal controller; adjusting the preliminary prediction based on the traffic signal variation data to form a corrected prediction of the state change of the target traffic signal; and using the corrected prediction to predict the state change of the target traffic signal. accessing a data store of traffic signal timing plans associated with a target traffic signal; accessing a data store of traffic signal schedules used for selecting one at a time of the traffic signal timing plans associated with the target traffic signal; based on a current date-time stamp and the traffic signal schedules, identifying one of the traffic signal timing plans as a currently selected timing plan; acquiring a preliminary prediction of a state change of the target traffic signal, the preliminary prediction based on the currently selected timing plan; identifying a traffic signal controller associated with the target traffic signal; acquiring traffic signal variation data for the traffic signal controller associated with the target traffic signal, comprising: generating baseline predictions for selected state change events of the traffic signal controller based on the traffic signal timing plans and corresponding timing plan schedules; monitoring real-time state change events of the traffic signal controller, and recording the events along with corresponding timestamps; comparing a timestamp of a baseline prediction to a timestamp of a corresponding one of the real-time state change events to determine a deviation datum for the state change event; and repeating the comparing step for additional real-time state change events to form the traffic signal variation data for the traffic signal controller; generating baseline predictions for selected state change events of the traffic signal controller based on the traffic signal timing plans and corresponding timing plan schedules; monitoring real-time state change events of the traffic signal controller, and recording the events along with corresponding timestamps; comparing a timestamp of a baseline prediction to a timestamp of a corresponding one of the real-time state change events to determine a deviation datum for the state change event; and repeating the comparing step for additional real-time state change events to form the traffic signal variation data for the traffic signal controller; adjusting the preliminary prediction based on the traffic signal variation data to form a corrected prediction of the state change of the target traffic signal; and using the corrected prediction to predict the state change of the target traffic signal.