Missouri CDL Combination Practice Test (MO) 2

5 out of 5 (45 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Prepare for your Missouri CDL combination test with this comprehensive Missouri permit practice test, designed to boost your confidence and knowledge. This Missouri DMV practice test, featuring 20 multiple-choice questions, covers crucial topics such as inspection procedures, safe driving practices, air brake systems, and more. With decades of experience, our professional driving instructors have crafted and reviewed each question to ensure they meet the highest standards. You'll need to correctly answer at least 16 questions to pass, helping you gauge your readiness for the actual permit test. Missouri presents unique driving conditions that every commercial driver should be prepared for. In the Ozarks, for instance, drivers must navigate winding, hilly roads that require precise handling and control. The flat farmlands of northern MO, on the other hand, may seem easier but pose their own challenges, like sudden crosswinds and long, monotonous stretches that test a driver's endurance and concentration. Whether you're driving through the urban congestion of St. Louis or the rural routes near the Missouri River, being well-versed in safe driving practices is essential. Our Missouri CDL combination test is regularly updated to reflect the most current driving laws and regulations. This ensures that the information you're studying is always relevant and up-to-date, particularly for the 2026 regulations. The drivers license practice test doesn't replace a state-certified drivers ed or ELDT course, but it serves as an excellent supplement to enhance your understanding of the materials. One critical area covered in this combination CDL test is the risk of jackknifing, where the trailer swings out of alignment with the tractor, creating a potentially dangerous situation. The Missouri practice permit test teaches you how to avoid jackknifing through smooth braking and careful handling, which are vital skills for any safe driver. By practicing with our Missouri combination CDL practice test, you'll learn how to handle a combination vehicle confidently and safely. Prepare yourself with our reliable Missouri CDL combination test and gain the confidence needed to succeed. Use this combination vehicle test alongside your drivers ed to thoroughly prepare for the challenges of driving a commercial vehicle in Missouri. Start practicing today and ensure you are well-prepared for the Missouri CDL combination test.
FREE CDL Practice Test App
Pass your Missouri CDL Combination Vehicles test with the NextDoorDriving app. Real questions and answers—100% free and ad-free.
Download on the App Store

Sample Missouri Combination Test Questions

Question 1

According to the standard coupling sequence, what is the first step when connecting a tractor to a semitrailer?

  1. A Connect the trailer air lines
  2. B Inspect the fifth wheel
  3. C Back completely beneath the trailer
  4. D Raise the landing gear

Correct answer: B – Inspect the fifth wheel

The coupling sequence begins with an inspection of the fifth wheel. Check for damaged or missing parts, secure mounting, required lubrication, open jaws, and proper positioning for coupling. If the tractor has a sliding fifth wheel, its locking pins must be engaged. The air lines and other connections are handled later in the coupling procedure.

Source: Missouri Commercial Driver License Manual — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 2

Before coupling, which conditions should be verified at the fifth wheel?

  1. A No parts are damaged or missing
  2. B The locking jaws are open and ready to receive the kingpin
  3. C The fifth-wheel plate is lubricated as required
  4. D All of the above

Correct answer: D – All of the above

The Missouri coupling procedure requires a complete fifth-wheel inspection before backing under the trailer. The driver checks for damaged or missing parts, secure mounting, proper lubrication, and the correct coupling position. The locking jaws should be open, and the unlocking handle should be positioned for automatic locking. A sliding fifth wheel must also be locked in place.

Source: Missouri Commercial Driver License Manual — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 3

Rearward amplification can make a quick steering movement at the tractor produce a greater rollover risk toward the rear of a combination.

  1. A True
  2. B False

Correct answer: A – True

Rearward amplification produces the crack-the-whip effect in vehicles pulling trailers. During a quick lane change, movement can be amplified toward the rear, making the last trailer especially vulnerable to rollover. Combinations with multiple trailers generally experience more amplification. Drivers should steer gently and smoothly, avoid sudden lane changes, and reduce speed before entering turns.

Source: Missouri Commercial Driver License Manual — § 6.1.2, “Steer Gently”

Question 4

After coupling, you should look into the back of the fifth wheel to verify that the jaws have closed around the kingpin shank.

  1. A True
  2. B False

Correct answer: A – True

After securing the coupled vehicle, inspect the fifth wheel from behind, using a flashlight if necessary. Verify that the locking jaws have closed around the shank of the kingpin, not merely around its head. Also check that there is no space between the upper and lower fifth wheel and that the locking lever and safety latch are correctly positioned. Do not drive if the coupling is incorrect.

Source: Missouri Commercial Driver License Manual — § 6.4.1, “Coupling Tractor-Semitrailers”

Question 5

What is the proper use of a trailer hand valve?

  1. A To assist the foot brake during every stop
  2. B To hold a loaded trailer while parked
  3. C To stop the combination during an emergency
  4. D To test the trailer brakes

Correct answer: D – To test the trailer brakes

The trailer hand valve, sometimes called a trolley valve, should be used only to test the trailer brakes. Using it while driving applies only the trailer brakes and can cause the trailer to skid. Normal stops should be made with the foot brake, which applies the service brakes throughout the combination. The hand valve must not be used as a parking brake because air leakage could release the brakes.

Source: Missouri Commercial Driver License Manual — § 6.2.1, “Trailer Hand Valve”

Question 6

According to the CDL manual, a fully loaded rig is how many times more likely to roll over in a crash than an empty rig?

  1. A Two times
  2. B Three times
  3. C Five times
  4. D Ten times

Correct answer: D – Ten times

The Missouri manual states that a fully loaded rig is ten times more likely to roll over in a crash than an empty rig. Cargo raises the vehicle's center of gravity, especially when it is stacked high. Keep cargo as low, centered, and evenly distributed as possible. Drivers must also slow before curves and avoid sudden steering movements, particularly with a full load.

Source: Missouri Commercial Driver License Manual — § 6.1.1, “Rollover Risks”

More Missouri CDL Practice Tests
Other CDL Endorsements