A method and an apparatus for changing a motor vehicle in an autonomous travel mode to a safe state when the driver of the motor vehicle is not able to monitor the autonomous travel mode and to assume control of the motor vehicle. The vehicle driver is warned using warning signals of increasing intensity; other road users in the area surrounding the motor vehicle are warned using optical and/or acoustic signals; the motor vehicle is braked and/or accelerated repeatedly such that parts of the body of the vehicle driver noticeably move in the direction of travel owing to inertia (the braking and/or acceleration being so brief that the travel speed of the motor vehicle changes relatively little); and the motor vehicle is brought to a standstill or is kept at a standstill by automatic braking in order to change the vehicle to a safe state.