According to (8) above, Figure 9 shows the estimated traffic information, i.e., the speed of next time zone, of each road segment in the electronic map, where each road segment is colored in green, yellow or red to represent the low, normal or high congestion level respectively after the vehicle under navigation has exchanged its recorded traffic information with others. Details of the exchanged traffic information such as the list of road segments and the estimated speed of the chosen road segment can be examined,as shown in Figure 9.