An actual running distance ab from a starting position to a present position of a vehicle is calculated based on input starting position data and positions continuously detected using a GPS device etc. An estimated running distance bc from the present position to a destination is calculated based on a detected present position and input destination data. A degree of attainment T representing a degree of approach to the destination is calculated according to an equation of: T=ab/(ab+bc), and is indicated on a display to announce it to a driver.