Kia Optima: Auto door lock/unlock feature (if equipped)

Impact sensing door unlock system (if equipped)

All doors will automatically unlock when an impact causes the air bags to deploy. ...

Speed sensing door lock system (if equipped)

All doors will be automatically locked after the vehicle speed exceeds 15 km/h (9.3 mi/h). And all doors will be automatically unlocked when you turn the engine off or when you remove the ignition ...

See also:

Winter Driving
We recommend that you carry emergency equipment, including tire chains, a window scraper, windshield de-icer, a bag of sand or salt, flares, a small shovel and jumper cables. Make sure you ...

To Resume the Preset Speed
The vehicle will automatically resume the speed set prior to cancellation when you press and release the RES/ACCEL switch, providing the vehicle speed is above 25 mph (40 km/h). ...

Passenger Airbag (PAB) Module. Description and Operation
Description The passenger airbag (PAB) is installed inside the crash pad and protects the front passenger in the event of a frontal crash. The SRSCM determines if and when to deploy the PAB. ...