Running control apparatus and running control program for the apparatus

A running control program, executed in a computer to operate a running control apparatus, comprising:

• a control-required driving or braking force calculating routine that calculates a control-required driving force or a control-required braking force, required to control a vehicle to a target running state, from a running resistance caused by the vehicle such that the driving or braking force contains a feed-forward component required to run the vehicle at the target running state against the running resistance;
• a driver-required braking force calculating routine that calculates a driver-required braking force of the vehicle required by a braking operation which is performed by a driver of the vehicle;
• and
• a running control routine that performs a running control for the vehicle to run the vehicle by the control-required driving or braking force calculated in the control-required driving or braking force calculating routine, stops the running control, when the driver-required braking force is higher than the control-required braking force, to run the vehicle at the driver-required braking force, judges, when the driver-required braking force becomes lower than a braking operation release judging threshold, that the braking operation is released, and restarts the running control when the driver-required braking force becomes lower than the control-required braking force or the braking operation release judging threshold.