A vehicle has a shift mechanism and a position detection device that detects an operation position of the shift mechanism. A transmission is brought to a power transmission state when an operation unit of the shift mechanism is operated to a driving position, and is brought to a power interrupt state when the operation unit is operated to a non-driving position. A driving force limitation process for reducing the driving force of an internal combustion engine is executed when it is determined that the non-driving position has been shifted to the driving position on the basis of the operation position of the operation unit as detected by the position detection device. The driving force limitation process is prohibited when it is determined that the vehicle is traveling and that the operation unit is not operated to any of the operation positions.