Question 1 of 20
A combination vehicle requires more time to stop than a single vehicle because:
Correct. Greater weight + brake-lag in long air lines = longer stopping distance. Plan ahead.
Rhode Island Combination Vehicles CDL Practice Test
This is a free 20-question practice test for the Combination Vehicles portion of the Rhode Island Commercial Driver's License knowledge exam. Questions are pulled from a pool of 55 drawn from the AAMVA CDL Manual, which is the source document the Rhode Island Division of Motor Vehicles uses to write its actual exam.
How it works: Click an answer. The correct choice highlights in green, and you'll see a short explanation. Aim for 85% or better before you sit for the real test in Rhode Island.
Question 2 of 20
When making a right turn at an intersection in a tractor-trailer:
Correct. Make the turn from the right lane. If you must swing wide, do so as you complete the turn, never before — swinging left first invites a vehicle to pass on your right.
Question 3 of 20
To recover from a trailer skid, you should:
Correct. Release the brakes so the trailer wheels can rotate again and re-establish traction. Continued braking will worsen the skid.
Question 4 of 20
A jackknife happens when:
Correct. Jackknife is when the drive wheels skid and the trailer continues forward, causing the tractor to pivot — the rig folds at the fifth wheel like a closing knife.
Question 5 of 20
When uncoupling, you should lower the landing gear:
Correct. Lower the landing gear and snug it against the ground before releasing the fifth-wheel jaws so the trailer doesn't drop when you pull away.
Question 6 of 20
When you supply air to the trailer for the first time after coupling, you should:
Correct. Charge the trailer system. Then test the trailer brake function by tugging gently or pulling the trailer-supply knob to confirm trailer brakes apply.
Question 7 of 20
The most likely cause of a tractor jackknife is:
Correct. When drive wheels lose traction (locked, oversteer, ice), the tractor pivots ahead of the trailer — a jackknife.
Question 8 of 20
When backing a tractor-trailer in a straight line, you should:
Correct. When backing straight, watch the trailer in your mirrors and make small steering corrections to keep it tracking straight. Big corrections lead to jackknifing.
Question 9 of 20
When you connect the glad-hands, you should:
Correct. Push the glad-hands together so the rubber seals match, then rotate to lock. Be sure red goes to red and blue goes to blue (the lines themselves often cross to keep colors matched).
Question 10 of 20
When coupling, after backing under the trailer, you should:
Correct. A tug test confirms the kingpin is fully engaged. Skipping it is the leading cause of trailer drops shortly after coupling.
Question 11 of 20
A "trailer skid" happens when:
Correct. When trailer wheels lose traction (often from over-application of trailer brakes alone), the trailer can slide sideways — a trailer skid or trailer swing.
Question 12 of 20
Maximum allowable trailer-brake leakage rate (engine off, brakes released, combination vehicle) is:
Correct. Combination vehicles: no more than 3 psi/min with brakes released, 4 psi/min with brakes applied.
Question 13 of 20
Before backing under a trailer to couple, you should:
Correct. Trailer should be just low enough that the fifth wheel will lift it slightly. Too low: the fifth wheel hits the trailer body. Too high: the fifth wheel slides under without engaging the kingpin.
Question 14 of 20
A high-mounted trailer kingpin is dangerous because:
Correct. If the trailer is too high, the fifth wheel slides under without the kingpin engaging the locking jaws. The trailer is not coupled and can drop when you pull away.
Question 15 of 20
Before uncoupling, you should:
Correct. Proper sequence: park level, lower landing gear to support the trailer, disconnect lines, release jaws, then pull forward slowly. Skipping any step risks dropping the trailer.
Question 16 of 20
Cargo securement: the heaviest part of the load should be:
Correct. Loading heavy cargo to the front of the trailer over the drive axles helps with traction; loading to one side or top creates dangerous handling.
Question 17 of 20
The "rearward amplification" effect:
Correct. Rearward amplification — the crack-the-whip effect — is most severe in the rear trailer of a multi-trailer combination.
Question 18 of 20
A combination-vehicle pre-trip should include:
Correct. You inspect the entire rig — tractor + trailer + connections + cargo securement — not just the tractor.
Question 19 of 20
A sliding-tandem trailer allows you to:
Correct. Sliding tandems shift trailer axles forward (more weight on tractor) or aft (more weight on trailer axles), helping meet axle-weight limits.
Question 20 of 20
Trailer rollover is more likely when:
Correct. High cargo and uneven side-loading raise the center of gravity, increasing rollover risk on curves and ramps.
About the Rhode Island Combination Vehicles exam
Most states administer 20 Combination Vehicles questions and require 80% to pass. The exam emphasizes the unique handling of articulated vehicles: how trailers track behind the tractor, how to prevent rollover, how to manage rearward amplification with multi-trailer combinations, and the correct sequence to couple and uncouple.
The Rhode Island Division of Motor Vehicles follows the federal CDL standards established by FMCSA. To earn the Combination Vehicles credential, you must answer at least 80% of the questions correctly. Many candidates score lower the first time because the test pulls from a large pool — refreshing this page will give you a different mix of questions, drawn from the same authoritative source.
Want more practice? Try the full Combination Vehicles question bank or browse all Rhode Island CDL practice tests.