Methods and systems for creating an approach map for a traffic signal preemption controller. A road map is displayed, and in response to user input for instantiating a first segment of an approach map, a first instance of a graphical object overlaying one of the plurality of roads is displayed. The one road represents an approach road to an intersection having the preemption controller. First segment location data that describes a first geographical area bounded by the first segment are determined from size and placement of the first instance of the graphical object on the road map and from location data associated with the one road. The first segment location data are stored in association with the approach map for the preemption controller. The preemption controller, once configured with the first segment location data, initiates traffic signal preemption in response to a preemption request transmitted from within the first geographical area described by the first segment location data.