PROCESSOR AND PROCESSING METHOD

A processor stores map data that includes position data on a plurality of intersections connected to a plurality of roads; receives road traffic information that includes starting-point position data indicating a starting point of a first zone, end-point position data indicating an end point of the first zone, first distance information indicating a length of the first zone, and second distance information indicating a length from a starting point or end point to a start position or a tail end of a caution zone where there is a traffic jam or traffic control; and displays a map that shows the caution zone by the length corrected and indicated by the corrected second distance information.