PURPOSE: To increase usability when the travel speed of a vehicle reaches a regulation speed by operating an acceleration switch and the regulation speed is made to be a new set travel speed, during a fixed speed travel control, by indicating, by the operation of an indicating means, that the travel speed of the vehicle has reached the regulation speed and increase has been stopped.

CONSTITUTION: When a fixed speed travel set switch 20A is in an ON condition, a fixed speed travel control unit 12, if a travel speed by means of a car speed sensor 22 at this time is less than a predetermined regulation speed, memorizes this travel speed as a set travel speed in a memory, and conducts a fixed speed travel control that maintains the set travel speed. That is, the opening of a throttle valve 23 is regulated by means of an actuator 24 in accordance with a travel speed variation. In this instance, when the travel speed has reached the regulation speed while an acceleration switch 20B is made to be ON and a travel speed increase regulation is being conducted, an indicator lamp 17 is switched on and off, and it is indicated that the fixed speed travel control is being made with the regulation speed being made to be the set travel speed.