What should you do before leaving a parked passenger vehicle?

Correct answer: Use the proper gear, set the parking brake, stop the engine, lock the ignition and take the key.

Why

Secure the vehicle before leaving: use the proper parked gear, set the parking brake, stop the engine, lock the ignition and remove the key. On a grade, position the wheels to keep a roll from carrying the vehicle into traffic. A transmission setting alone may not hold a vehicle securely. The parking brake and appropriate wheel position provide additional protection against an unattended vehicle rolling into traffic.

Verified against Mississippi Driver's License Manual · Parking · p. 60