A vehicle airbag system includes an airbag module, a seat detector, and an electronic controller. The airbag module has an airbag that is configured to be movably mounted to a vehicle roof structure. The seat detector detects a position of a vehicle seat. The electronic controller is in communication with the airbag module and the seat detector. The controller controls the airbag module to inflate the airbag in a predetermined direction based on detected position of the vehicle seat by the seat detector.