Massachusetts CDL Combination Vehicles Practice Test

The Massachusetts CDL Combination Vehicles test is a multiple-choice knowledge test you take for your commercial learner's permit. Massachusetts Registry of Motor Vehicles (RMV) says you need 80% to pass (source).

Last updated Oct 7, 2026. FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC.

By Scott Wilder, Editor

Last reviewed against the Massachusetts CDL manual on October 7, 2026

Scott Wilder on X | scottwilderhq.com

FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC. It offers free exam-style practice tests built from the official CDL manual. FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.

Massachusetts CDL permit facts

What	What Massachusetts says	Source
Combination Vehicles pass mark	80%	Official page
Combination Vehicles test questions	20	Official page
CLP fee	$30 permit application fee	Official page
CLP validity	180 days from the date of issue	Official page
Test languages	CLP general knowledge and all endorsement exams are offered in English, Spanish and Portuguese. The road test must be given in English, and per federal regulation a foreign language interpreter is not permitted. The skills test sheet says a person is not eligible to operate a CMV unless they can read and speak English well enough to talk with the public, understand highway signs, answer official questions and make entries on reports (49 CFR 391.11).	Official page

20 question Combination Vehicles practice test

1. Cargo is loaded toward one side and makes the trailer lean. What is the result?
1. A. The trailer tracks better in turns
2. B. A rollover is more likely
3. C. Braking distance gets shorter
4. D. Nothing, if the weight is within legal limits
Show answer
Answer: B. A rollover is more likely
A load off to one side makes the trailer lean, which makes a rollover more likely.
From the official CDL manual, section 6.1.1.
2. On some fifth wheels, how is the safety latch put in place?
1. A. It moves into place by itself every time
2. B. By hand
3. C. With a wrench
4. D. With the tractor brakes
Show answer
Answer: B. By hand
On some fifth wheels the catch must be put in place by hand.
From the official CDL manual, section 6.4.1.
3. When should you slow down for a turn in a tractor-trailer?
1. A. Halfway through the turn
2. B. Before you go into the turn
3. C. After the turn is finished
4. D. Only if the road is wet
Show answer
Answer: B. Before you go into the turn
You must slow to a safe speed before you enter the turn.
From the official CDL manual, section 6.1.2.
4. During the coupling inspection, around what part of the kingpin must the jaws be closed?
1. A. The head
2. B. The base plate
3. C. The top
4. D. The shank
Show answer
Answer: D. The shank
The fifth wheel jaws must close around the shank of the kingpin.
From the official CDL manual, section 6.4.1.
5. What can happen if the fifth wheel plate is not greased?
1. A. The trailer brakes will lock
2. B. The air-lines will cross
3. C. Steering problems from friction between the tractor and trailer
4. D. The kingpin will lock open
Show answer
Answer: C. Steering problems from friction between the tractor and trailer
The manual says lack of lubrication could cause steering problems.
From the official CDL manual, section 6.4.1.
6. Besides colors, what can help you join the correct glad hands?
1. A. Hoses of different lengths
2. B. Different rubber seal shapes
3. C. Metal tags stamped "service" and "emergency"
Show answer
Answer: C. Metal tags stamped "service" and "emergency"
Metal tags marked service and emergency help you avoid mixing up the lines.
From the official CDL manual, section 6.2.5.
7. What can happen if you do not lock the pintle hook latch correctly?
1. A. Only a small noise
2. B. The trailer and vehicle can separate
3. C. The brake lights stay on
4. D. The tires wear faster
Show answer
Answer: B. The trailer and vehicle can separate
The trailer and vehicle can separate, which can cause death or serious injury.
From the official CDL manual, section 6.4.3.
8. In Step 5 of coupling, after you back until the fifth wheel touches the trailer, what do you do?
1. A. Shut off the engine and remove the key
2. B. Put on the parking brake and put the transmission in neutral
3. C. Back under the trailer right away
4. D. Connect the electrical cord
Show answer
Answer: B. Put on the parking brake and put the transmission in neutral
Step 5 is to put on the parking brake and put the transmission in neutral.
From the official CDL manual, section 6.4.1.
9. How do you join two glad hand couplers?
1. A. Push them straight together until they click
2. B. Twist them together while pulling the hoses apart
3. C. Slide one coupler over the other and tighten it with a wrench
4. D. Press the seals together with the couplers at 90 degrees, then turn the hose-side glad hand
Show answer
Answer: D. Press the seals together with the couplers at 90 degrees, then turn the hose-side glad hand
This presses the seals and locks the couplers.
From the official CDL manual, section 6.2.5.
10. Triples have a rearward amplification of 3.5. How easily can the last trailer roll, compared with a five-axle tractor?
1. A. 1.5 times as easily
2. B. 3.5 times as easily
3. C. 2 times as easily
4. D. 10 times as easily
Show answer
Answer: B. 3.5 times as easily
The manual says the last trailer of triples can roll 3.5 times as easily as a five-axle tractor.
From the official CDL manual, section 6.1.2.
11. The manual says to avoid quick lane changes, especially in what condition?
1. A. When the rig is fully loaded
2. B. When the rig is empty
3. C. When the road is dry
Show answer
Answer: A. When the rig is fully loaded
Quick lane changes are most risky when the rig is fully loaded.
From the official CDL manual, section 6.1.1.
12. During the walk-around, what should you see on the release arm of the lower fifth wheel?
1. A. It is pulled out to the open position
2. B. It is removed
3. C. It is covered with grease
4. D. It is properly seated and the safety latch is engaged
Show answer
Answer: D. It is properly seated and the safety latch is engaged
The release arm must be properly seated and the safety latch or lock engaged.
From the official CDL manual, section 6.5.1.
13. During the air flow check, what do you use to provide air to the service line?
1. A. The red trailer air supply knob
2. B. The tractor parking brake
3. C. The trailer handbrake
Show answer
Answer: C. The trailer handbrake
The trailer handbrake provides air to the service line.
From the official CDL manual, section 6.5.2.
14. What have tests shown about stopping a bobtail tractor?
1. A. It stops more smoothly than a loaded rig
2. B. It can be very hard to stop smoothly
3. C. It is easy to stop on any road
Show answer
Answer: B. It can be very hard to stop smoothly
Tests show bobtails can be very hard to stop smoothly, so drive them with care.
From the official CDL manual, section 6.1.3.
15. You are slowing down in a tractor-trailer with ABS. What should you do as you slow?
1. A. Watch the tractor and trailer and ease off the brakes if safe
2. B. Keep full brake pressure until you stop
3. C. Pump the brake pedal quickly
Show answer
Answer: A. Watch the tractor and trailer and ease off the brakes if safe
Monitor the tractor and trailer and back off the brakes, if safe, to stay in control.
From the official CDL manual, section 6.3.2.
16. A bobtail tractor is compared with a tractor-semitrailer at maximum gross weight. Which stops in less distance?
1. A. The bobtail, because it weighs less
2. B. They stop in the same distance
3. C. It depends only on tire tread depth
4. D. The loaded tractor-semitrailer
Show answer
Answer: D. The loaded tractor-semitrailer
Bobtails take longer to stop than a tractor-semitrailer loaded to maximum gross weight.
From the official CDL manual, section 6.1.3.
17. Before you uncouple, what must you check about the parking area?
1. A. That it is painted with lines
2. B. That it is close to the road
3. C. That the surface can support the weight of the trailer
4. D. That it is level with the road
Show answer
Answer: C. That the surface can support the weight of the trailer
The parking surface must support the weight of the trailer.
From the official CDL manual, section 6.4.2.
18. Which color code is commonly used for the service line and the emergency line?
1. A. Blue for service, red for emergency
2. B. Red for service, blue for emergency
3. C. Yellow for service, red for emergency
4. D. Blue for both lines, with metal tags to tell them apart
Show answer
Answer: A. Blue for service, red for emergency
The manual says red marks the emergency line and blue marks the service line.
From the official CDL manual, section 6.2.4.
19. You push in the trailer air supply control, but the spring brakes stay on. What should you check?
1. A. The ABS lamp bulb
2. B. The air-line connections
3. C. The fifth wheel grease
4. D. The trailer tires for proper inflation
Show answer
Answer: B. The air-line connections
The manual says to check the air-line connections if the spring brakes will not release.
From the official CDL manual, section 6.2.5.
20. Before coupling, how should the jaws of the fifth wheel be?
1. A. Closed
2. B. Locked on a shank
3. C. Greased and closed
4. D. Open
Show answer
Answer: D. Open
The manual says the fifth wheel jaws must be open for coupling.
From the official CDL manual, section 6.4.1.

Massachusetts CDL Combination Vehicles questions

What score do you need to pass the Massachusetts CDL Combination Vehicles test?

Massachusetts says you need 80% to pass the Combination Vehicles test.

Is the Massachusetts CDL Combination Vehicles test the same as other states?

The Combination Vehicles test is built on the same federal knowledge standards in every state, so the topics match the CDL manual. Massachusetts uses its own handbook: https://www.mass.gov/doc/cdl-manual-march-2025-version/download

How much does a CDL permit cost in Massachusetts?

CLP fee: $30 permit application fee.

What languages is the Massachusetts CDL knowledge test offered in?

CLP general knowledge and all endorsement exams are offered in English, Spanish and Portuguese. The road test must be given in English, and per federal regulation a foreign language interpreter is not permitted. The skills test sheet says a person is not eligible to operate a CMV unless they can read and speak English well enough to talk with the public, understand highway signs, answer official questions and make entries on reports (49 CFR 391.11).

Sources

https://www.mass.gov/how-to/apply-for-a-commercial-learners-permit-clp
https://www.mass.gov/doc/rmv-schedule-of-fees/download
https://www.mass.gov/news/massachusetts-registry-of-motor-vehicles-now-offering-commercial-learners-permit-exams-in-spanish-and-portuguese
https://www.mass.gov/doc/cdl-manual-march-2025-version/download
Manual sections used in this test: 6.1.1; 6.1.2; 6.1.3; 6.2.4; 6.2.5; 6.3.2; 6.4.1; 6.4.2; 6.4.3; 6.5.1; 6.5.2

Combination Vehicles practice test in nearby states