Arkansas CDL Combination Vehicles Test study guide
Arkansas CDL Combination Vehicles Test · Work through your exam, one topic at a time.
The Arkansas CDL Combination Vehicles knowledge test is the endorsement-area exam a driver must pass to operate a tractor-trailer or other combination vehicle - typically as part of earning a Class A commercial driver's license, or adding combination authority to an existing CDL. Arkansas administers the test through the Arkansas State Police's driver services network, and it draws on the federal commercial driver's license standards that Arkansas has adopted, so the content mirrors what combination drivers are tested on nationwide. The Arkansas CDL Combination Vehicles Test study guide has 8 sections and about 2,276 words.
01Driving Combination Vehicles Safely
A combination vehicle is two or more units connected by a hitch, and its handling differs from a single truck in three ways: it is heavier, it is longer, and it bends at the coupling point. The most tested concept is off-tracking - the rear wheels of the trailer follow a shorter path than the front wheels of the tractor, so the trailer cuts the corner.
345 words, about 2 min02Air Brakes and Brake Systems on Combination Vehicles
A combination vehicle uses a dual air-brake system with a tractor protection valve that separates the tractor's air supply from the trailer's. The trailer hand valve (also called the trolley valve) lets you apply only the trailer brakes; it is used during coupling checks and for testing.
287 words, about 1 min03Antilock Braking Systems (ABS)
ABS prevents wheel lockup during hard braking so you can maintain steering control. It does not shorten stopping distance on all surfaces, and it does not replace safe following distance.
296 words, about 1 min04Coupling and Uncoupling
Inspect the fifth wheel and kingpin; ensure the fifth wheel is open and greased. Back under the trailer slowly, aligning the tractor squarely.
265 words, about 1 min05Inspecting Combination Vehicles
A proper pre-trip inspection follows a fixed order: (1) vehicle overview, (2) engine compartment, (3) cab and controls, (4) walk-around inspection, (5) brake check, (6) coupling system check, and (7) trailer check. For combination vehicles, the coupling system and trailer steps deserve extra attention.
257 words, about 1 min06Tractor-Trailer Handling and Turning
A combination vehicle turns around a point near the rear wheels of the tractor, not the front bumper. When making a right turn, swing wide to the left so the trailer does not cut the corner or hit the curb.
286 words, about 1 min07Skid Control, Jackknifing, and Emergency Procedures
A jackknife occurs when the trailer pushes the tractor sideways, folding the combination at the coupling. It is most often caused by overbraking the tractor (especially the drive wheels) or by driving too fast on a slippery surface.
275 words, about 1 min08Cargo Securement and Weight Distribution
Federal limits are 80,000 lb gross , 20,000 lb per axle , and 34,000 lb per tandem axle . Weight must be distributed so no axle is overloaded and the steer axle retains enough weight for steering control (typically at least 12,000 lb on a loaded tractor).
265 words, about 1 min