Although it is unquestionable that intelligent transportation systems (ITS) will be effective in improving traffic problems, including congestion and safety, some concerns must be addressed about the serious problem of ITS rat-runners that invade neighborhood streets with vehicles that are equipped with car navigation systems. Because drivers of such vehicles can easily identify their locations and direction to their destinations, they may use local streets when, for example, arterial streets are congested and without any concern about losing their way in neighborhoods. This problem should be solved from the viewpoint of neighborhood safety. To study the problem of "intelligent rat-runners," the authors dealt with this problem as the "way-finding problem" in cognitive-psychology in terms of car drivers. To this end, a psychological experiment was conducted. Subjects were asked to drive from an origin to a destination within an urban area, where they had never been, with a map of the area. They were asked to drive four times per subject, searching for "better" routes. In the experiment, using the protocol and cognitive-map methods, the mechanism of finding and choosing routes was analyzed. In the experiment, both conventional cars and cars with car navigation systems were used to compare the drivers' behavior. Through comparative analysis, it was found that drivers with car navigation systems tended to choose routes of which direction is as direct as possible to the destination, and that they would use local streets to follow the direction, which normal drivers would never use.