Navigation instrument

摘要

A navigation instrument for use with a roadway vehicle comprises an arithmetic means producing three data signals showing the average speed of the vehicle, the deviation of the travelling distance from a scheduled one, and the deviation of the travelling time from a scheduled one, and a display means for displaying the three data sequentially fed from the arithmetic means through a signal selector means. The arithmetic means includes travelling distance/time deviation accumulating means for adding the deviation of the travelling distance/time with respect to the average speed initially set to the deviations of the travelling distance/time whenever the average speed is altered. Thus, the navigation instrument of the present invention makes it possible to calculate and display the travelling distance/time deviation accumulated value when the average speed of the vehicle is altered on the way of vehicle travelling.