Maryland CDL Combination study guide
Maryland CDL Combination · Work through your exam, one topic at a time.
The Maryland CDL Combination Vehicles knowledge test is the written exam a driver must pass to add the Class A combination-vehicle endorsement path to a Maryland commercial learner's permit or CDL. It matters most to people who intend to pull a tractor-trailer or a truck plus trailer, where the coupling, pivot points, and air brake systems behave very differently from a single-unit truck. The test is drawn from the combination vehicles portion of the state CDL manual and is typically organized around four themes: pre-trip inspection and coupling/uncoupling procedures; safe driving of combination units, including turns, braking, off-tracking and speed control; air brake and brake system checks specific to multi-unit vehicles; and skid control, rollover prevention and hazard response. Expect multiple-choice items that reward precise procedural order - for example, the sequence of steps for a safe coupling, or the correct order of an air brake leakage test - rather than general road intuition. The Maryland CDL Combination study guide has 4 sections and about 1,400 words.
01Combination Vehicle Inspection and Coupling/Uncoupling
This domain tests whether you can verify a tractor-trailer is mechanically sound and securely joined before you move it. Exam questions focus on the fifth wheel, kingpin, air and electrical connections, landing gear, and the correct order of coupling and uncoupling steps.
355 words, about 2 min02Driving Combination Vehicles Safely
This domain tests how you manage a tractor-trailer's greater length, weight, and off-tracking during turns, braking, and speed changes. Questions often ask where the rear wheels will track and how to brake or descend a grade without losing control.
367 words, about 2 min03Air Brakes and Brake System Checks on Combination Vehicles
This domain tests your ability to inspect and test the tractor-trailer air brake system, including trailer protection devices and leakage limits. You must know the order of tests and what a failed reading means.
352 words, about 2 min04Skid Control, Rollover Prevention, and Hazard Response
This domain tests how you prevent and respond to loss of traction, rollover risk, and sudden hazards in a combination vehicle. The tractor-trailer's high center of gravity and articulation make recovery different from a car.
326 words, about 2 min