With GIS Centerlines, the Devil Often is in the Details
Public safety agencies draw polygons using their geographic information systems (GIS) that define their jurisdictional footprints and the areas in which they provision emergency services. When such polygons abut, generally along jurisdictional borders, they must “snap” to each other; another way of expressing that is to say that the polygon borders must be coincident. If they are not, overlaps and/or gaps can occur—both are problematic from an emergency response perspective. Jurisdictional boundaries most often are in the form of road centerlines, which represent the center of a real-world road.