South Carolina CDL Permit Test - Double

Number of questions: 20
Passing score: 16
Directions: This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test. The test consists of 20 multiple choice questions. To pass, the applicant must answer at least 16 questions correctly. Each question has two, three or four possible answer choices. Test questions come from the South Carolina Commercial Driver License Manual. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.
You have made error so far
Passing grade —
4 or fewer errors
One way to prevent becoming an aggressive driver is by:
Talking on your cell phone while driving.
Questioning others' driving abilities.
Setting realistic expectations regarding travel time.
How is the parking brake released?
By tapping the brake pedal three times
By pushing in the brake control knob
By starting the vehicle
By tapping the accelerator twice
Bent lock rings:
Are not a concern in dry weather
Are dangerous
Can lengthen tire life
Why do larger vehicles use air brakes?
Other brake systems will squeak too loudly
Air brakes are very effective systems
Air brakes are complicated
Air is free
Maintaining a cushion of space between your vehicle and the vehicle ahead is:
Not encouraged, as it slows the flow of traffic.
Encouraged, as it allows you time to react to unexpected hazards.
Only encouraged if you are traveling with a passenger.
What does ABS do?
Allows the wheels to lock up
Prevents wheels from locking up
Makes it easier to turn
To control a surge, when stopping:
Do not keep a steady pressure on the brakes
Try not to brake in advance of a stop
Do not release the brakes too soon
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