Side impact crashes account for nearly half of all traffic fatalities. These center airbags stop the 2 front occupants from "Bumping Heads" so to speak.
While many auto manufacturers provide side impact airbags, passengers on the opposite side of the impact lacked the protection of the airbag. The new airbag deploys from the drivers seat towards the center of the vehicle. It provides protection for the person on the non-impact side of the vehicle.
This new technology was first provided in the 2009 GM Crossover SUV's (Traverse/Acadia/Enclave). This technology has also now spread to the full size GM SUV's (Tahoe/Suburban/Yukon/Escalade).