Japanese Patent Laid-Open No. 345541/1992 discloses a method which controls at least one of the engine torque adjustment means, transmission gear ratio adjustment means, and braking force adjustment means, so that a target acceleration/deceleration requested by a driver equals the actual motor vehicle acceleration/deceleration.
In a system for performing control in accordance with only a target acceleration/deceleration requested by a driver, such as in the above prior art, a traffic accident or speeding may occur if the driver erroneously recognizes a forward traveling condition, or responds too slowly to a traveling condition. Moreover, previous confirmation of a road gradient or a corner becomes insufficient, and it is difficult to secure a sufficient driving force before entering a slope or corner by controlling a transmission gear ratio.