A vehicle is provided with a navigation system that includes a traffic information receiver and a radio receiver. The traffic information receiver receives traffic information from one of multiple traffic information broadcasting stations having respective service regions. The radio receiver selectively receives (i) traffic information from one of the multiple traffic information broadcasting stations and (ii) a radio program from a radio broadcasting station. When the vehicle approaches a border between (i) a current service region where the traffic information receiver is receiving traffic information and (ii) a neighboring service region, whether the radio receiver is in use or not is determined. Based on the determination, the traffic information receiver or the radio receiver is tuned to a traffic information broadcasting station covering the neighboring service region.