Maryland Combination Vehicles CDL Practice Test
Below are 25 exam-style questions for the Maryland Combination Vehicles CDL knowledge test, modeled on the FMCSA-aligned content used by the Maryland Motor Vehicle Administration. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.
- A Engine damage
- B Tire wear only
- C Rust on the cab
- D The trailer to come uncoupled
- A Round, blue, marked TRACTOR
- B Octagonal, red, marked TRAILER AIR SUPPLY
- C Square, white, marked CHARGE
- D Triangular, green, marked SERVICE
- A Connect only air; electrical is optional
- B Connect electrical first, then air
- C Connect air emergency line first, then service line, then electrical (or per company policy) — verify with brake check
- D Connect any line first; order doesn't matter
- A Pressing the pedal once at startup
- B Performing the seven-step air-brake check before each trip
- C Listening to the brake light
- D Asking a mechanic
- A Stop suddenly
- B Roll over before sliding
- C Lose engine power
- D Spin out
- A Electrical power for trailer lights and ABS
- B Air for the brakes
- C Fuel
- D Hydraulic fluid
- A Empty
- B Loaded
- C Too high — it can damage the kingpin or skip over the fifth wheel
- D Properly chocked
- A Have the dispatcher in the cab
- B Use only mirrors
- C GOAL — Get Out And Look — and walk around the trailer first
- D Back at full speed
- A It is illegal in some states
- B It is the standard procedure
- C It is fine if you are careful
- D It can damage the cab and the trailer (cab corner crush)
- A A height that requires the tractor to drop down to fit
- B Whatever height it happens to be
- C Maximum legal height
- D A height where the tractor will lift the trailer slightly when backing under
- A Loaded last
- B First (closest to the tractor)
- C Either position is fine
- D Last
- A Engine wear
- B Cargo placement
- C Driver fatigue
- D Air leakage in the supply line, low pressure, or a brake-balance issue
- A Trailer sway in crosswinds
- B Reduced visibility along the trailer
- C Off-tracking on right turns
- D All of the above
- A Back to the left whenever possible because you can see better
- B Back as fast as practical
- C Back without using mirrors
- D Always back to the right
- A No off-tracking
- B Wheel damage
- C Brake fade
- D Off-tracking — the trailer wheels follow a tighter arc than the tractor
- A Misalignment between tractor and trailer
- B Loose or missing fifth-wheel mounting bolts
- C Cracks in the kingpin
- D All of the above
- A Leave the gear up
- B Lower the landing gear all the way until firmly on the ground, then a few extra cranks
- C Use blocks instead
- D Raise the gear partway
- A Two car lengths
- B One second per 10 feet of vehicle length below 40 mph, plus one extra second above 40 mph
- C No specific rule
- D A vehicle length
- A Be in the low position when traveling
- B Be locked at half-height
- C Be in the stowed (high) position when traveling
- D Be removed
- A Stop on the tracks if traffic ahead slows
- B Cross in a low gear without shifting
- C Shift in the middle of the track
- D Honk and accelerate
- A Drive wheels never lock
- B Trailer wheels lock more often than drive wheels in panic stops
- C Brake balance is irrelevant
- D ABS prevents jackknife in all cases
- A They take more skill to back, couple, and uncouple
- B They have a higher rollover risk
- C All of the above
- D They are heavier and longer
- A Manual transmission shifters
- B Electrical connectors
- C Brake adjustment levers
- D Coupling devices for connecting tractor air lines to the trailer
- A By setting the red trailer-air-supply valve
- B By the trailer hand valve
- C By pulling out the red trailer-air-supply valve
- D By pushing in the red trailer-air-supply valve
- A Steering becomes easier
- B Stopping distances are normal
- C No effect on safety
- D Stopping distances increase and the trailer can swing
Study tips for the Maryland Combination Vehicles exam
The Combination Vehicles portion of the Maryland CDL exam is graded out of the bank of questions the Maryland Motor Vehicle Administration draws from each year. While the exact bank is not published, every question is sourced from the Combination Vehicles chapter of the Maryland CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.
Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official Maryland handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.
Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about Combination Vehicles.
Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The Maryland Motor Vehicle Administration will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.
Finally, keep your General Knowledge fundamentals sharp even when you're focused on the Combination Vehicles exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh Maryland General Knowledge practice test before scheduling the real exam.
Next steps
Missed more than four questions? Re-read the Combination Vehicles study guide and the matching chapter in the official Maryland CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local Maryland Motor Vehicle Administration office.
Already comfortable with this endorsement? Drill another: MD General Knowledge · MD Air Brakes · MD Hazardous Materials · MD Passenger · MD School Bus · MD Tank Vehicle · MD Doubles / Triples
New to the CDL process in Maryland? Read How to apply for a CDL in Maryland for the document checklist and step-by-step timeline.