While backing out of a driveway into an unobstructed road with no oncoming traffic from either side nor any pedestrians or cyclists approaching, the automatic emergency braking system applied the brakes and then locked up leaving the vehicle as an obstruction in the road. To disengage the locked brakes required a large amount of pressure on the accelerator pedal bringing the engine RPMs up to a sufficient speed to disengage the automatic emergency braking system. Had there been traffic approaching what would have been an otherwise safe amount of time to bring the vehicle into the flow of traffic would have been insufficient and may have caused an accident. There was no warning indicating any of the vehicle sensors detected an approaching object or obstruction. This is the second incidence of the occurring in the last week.