Home › Practice › Combination Vehicles › Question 4

Combination Vehicles Practice Question 4

Required for Class ACombination Vehicles · Question 4

When coupling, you should approach the trailer:

• AAt an angle from the side
• BStraight on, lined up under the kingpin
• CFrom behind
• DWhile turning sharply

Correct answer: B. Straight on, lined up under the kingpin

Why: Approach straight, slowly, with the fifth wheel slightly below the trailer apron. Stop just short and check alignment before backing the rest of the way.

How this question fits the Combination test

Articulated vehicles fail in unique ways: trailer swing under braking, rearward amplification under steering, and jackknife under loss of traction. Combination Vehicle knowledge is required for any Class A applicant under 49 CFR 383.111.

Study technique for this topic

Walk through the coupling sequence verbally until it's second nature. Know the safe-rolling rearward amplification factor, the difference between trailer service brakes and parking brakes, and what creates the conditions for a tractor jackknife.

Related Combination practice questions

• Q7. The trailer's landing gear should be:
• Q20. When checking trailer brakes via the hand valve, you should:
• Q33. When the trailer wheels lock during heavy braking, you should:
• Q46. Inspecting the rear of a trailer at a stop should include:
• Q59. A combination vehicle's empty trailer:

Continue your CDL preparation

The Combination Vehicles portion of the CDL knowledge exam covers more than this single question. Use this site's full Combination Vehicles bank to drill every topic, then test yourself with one of our state-specific practice sets to confirm you are ready for the actual DMV exam in your state. Always check your state's CDL handbook for any local addenda before the test day.

If you are still building your overall CDL foundation, start with the General Knowledge bank — every CDL applicant must pass it — and then work outward to the endorsements you plan to add.