CDL Combination Vehicles TestDriving Combination Vehicles SafelyHard
When securing a combination vehicle for a long period, such as overnight parking, what is the most important step to prevent theft of the trailer or its contents?
- APlace chocks under the trailer wheels and deflate one of the trailer tires.
- BPark in a well-lit area and remove the keys from the ignition.
- CLeave the tractor's engine running to deter potential thieves.
- DDisconnect the trailer air lines and lock the trailer coupling (kingpin) with a security device.
Show answer & explanationAnswer & explanation
Correct answer: D. Disconnect the trailer air lines and lock the trailer coupling (kingpin) with a security device.
Disconnecting air lines renders the trailer brakes inoperable, making it difficult to move. Locking the kingpin prevents another tractor from coupling to and stealing the trailer, making this the most effective security measure.
Why the other options are wrong
- A. Chocks add some security, but deflating a tire is impractical, time-consuming, and not a primary security measure against determined thieves.
- B. While good practice, removing keys only secures the tractor. A well-lit area helps but isn't a physical deterrent for trailer theft.
- C. Leaving the engine running is wasteful, illegal in many places, and doesn't prevent trailer theft; it might even attract attention.
Trailer Security
To prevent trailer theft, disconnect air lines to set trailer brakes and use a kingpin lock to prevent unauthorized coupling.
- Kingpin lock is essential.
- Disconnect air lines for brake activation.
- Park securely.
Memory trick: Air Out, Pin Lock, No Truck Out.