detected by the speed sensor 3 according to this controlling amount the control system 13 controls the opening of the throttle valve 9 via the throttle actuator 7 so that the actual running speed is increased gradually when it is desired to stop the acceleration if a voice instruction registered as 34 stop 34 is input via the microphone 11 then the instruction is input to the control system 13 the control system 13 stores the actual running speed which is detected by the speed sensor 3 when the instruction is input as a new target speed thus the acceleration control process is completed then the target speed newly set in this way and the actual running speed detected by the speed sensor 3 are input to the control system 13 and the controlling amount is determined from the deviation of the actual running speed from the target speed the opening of the throttle valve 9 is controlled via the throttle actuator 7 according to the above controlling amount so that the vehicle runs at the target speed in an automatic running mode in this way the vehicle running control system performs the above described operation according to a voice instruction given by a driver a timing chart illustrating the operation of this embodiment is shown in fig6 fig1 is a.