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CDL General Knowledge Test · CDL General Knowledge Test

CDL General Knowledge Test: Basic Control, Shifting, and Backing Concepts

Importance ★★★☆☆ · 8% (estimate)

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Written by AI. Only units that passed a separate AI check (re-reading facts and numbers) are published. Tell us if you find a mistake.

Overview

This chapter covers the basic skills for moving a heavy vehicle under control: starting smoothly, steering firmly, stopping smoothly, backing safely, and shifting gears. These skills matter more in a large vehicle because mistakes take longer to correct.

When you start on a hill with a manual transmission, partly engage the clutch before you take your foot off the brake so you do not roll back. Hold the wheel firmly with both hands on opposite sides. Backing is always dangerous, so avoid it when you can. When you must back, do it slowly in the lowest reverse gear, toward the driver's side, and with a helper when possible.

Most heavy manual transmissions need double clutching. Downshift before you start down a hill and before you enter a curve. A retarder helps slow the vehicle and saves the brakes, but it can make the drive wheels skid, so turn it off on wet, icy, or snowy roads.

Key concepts

  • Backing safely

    Look at your path first, use mirrors on both sides, back slowly in the lowest reverse gear, back toward the driver's side, and use a helper when you can.

    Memory tipSlow, driver's side, with a helper.

  • Helper signals

    A helper stands near the back where you can see them and guides you through blind spots. Before backing, agree on hand signals, and above all on the signal for stop.

    Memory tipThe stop signal is the one that prevents crashes.

  • Double clutching

    A way to shift a manual transmission: clutch in and shift to neutral, release the clutch, match engine speed to the next gear, then clutch in and shift. If you miss a gear, return to neutral, match engine speed to road speed, and try again.

    Memory tipNever force a missed shift.

  • When to downshift

    Downshift before starting down a hill so you can control speed without hard braking, and before entering a curve so you can use a little power through it.

    Memory tipShift down before the hill and before the curve.

  • Retarder

    A device that slows the vehicle and reduces brake wear. It brakes only the drive wheels, so it can make them skid on wet, icy, or snow-covered roads. Turn it off in those conditions.

    Memory tipSlippery road, retarder off.

Often tested

  • Hold the steering wheel firmly with both hands on opposite sides.
  • Back slowly in the lowest reverse gear, toward the driver's side when possible.
  • Agree on a stop signal with your helper before backing.
  • Downshift before hills and curves.
  • Turn off the retarder on wet, icy, or snow-covered roads.

3 sample questions

Verified practice questions from this unit.

Practice questionReviewedCDL General Knowledge Test › Basic Control, Shifting, and Backing★★★★☆

Question 1. When you have to back up, which way is safest to back and turn?

  1. ① Toward the passenger (right) side
  2. ② Straight back without looking at the mirrors
  3. ③ Toward the driver's side
▼ Show answer and explanation▲ Hide answer and explanation

Answer: ③ Toward the driver's side

Key point: Back toward the driver's side

Back and turn toward the driver's side whenever you can. You can see the rear of your vehicle by looking out the side window. It is worth going around the block to set up a driver-side back.

Wrong choices

  • Toward the passenger (right) side: Backing to the right is very dangerous because you cannot see as well.
  • Straight back without looking at the mirrors: You should always use the mirrors on both sides.
Practice questionReviewedCDL General Knowledge Test › Basic Control, Shifting, and Backing★★★★☆

Question 2. When should you downshift?

  1. ① Only after the vehicle starts going too fast downhill
  2. ② In the middle of a curve
  3. ③ Before you start down a hill and before you enter a curve
▼ Show answer and explanation▲ Hide answer and explanation

Answer: ③ Before you start down a hill and before you enter a curve

Key point: Downshift before hills and curves

Downshift before starting down a hill so you can control speed without using the brakes hard. Downshift before entering a curve so you can use a little power through the curve and stay stable.

Wrong choices

  • Only after the vehicle starts going too fast downhill: By then it may be too late to get into a lower gear.
  • In the middle of a curve: Shift before the curve so you can use some power through it.
Practice questionReviewedCDL General Knowledge Test › Basic Control, Shifting, and Backing★★★☆☆

Question 3. How should you hold the steering wheel?

  1. ① Lightly, with one hand at the top of the wheel
  2. ② Firmly, with both hands on opposite sides of the wheel
  3. ③ With both hands close together at the bottom
▼ Show answer and explanation▲ Hide answer and explanation

Answer: ② Firmly, with both hands on opposite sides of the wheel

Key point: Both hands, opposite sides, firm grip

Hold the wheel firmly with both hands on opposite sides. If you hit a curb or pothole, the wheel can be pulled out of a loose grip.

Wrong choices

  • Lightly, with one hand at the top of the wheel: One hand cannot hold the wheel if you hit a pothole or curb.
  • With both hands close together at the bottom: This gives you poor control in a quick turn.
Practice 5 questions from this unit →