Arkansas CDL General Knowledge Test common mistakes
Arkansas CDL General Knowledge Test · Understand the traps and how to avoid them.
When asked about stopping distance, the candidate counts only the perception distance and the brake lag and forgets to add the distance travelled while the brakes are actually applied, so the total comes out far too short.
People treat a 'stopping distance' question as a memory item about one number rather than as a sum of stages, and the stage that happens after the pedal is down feels like the end of the process rather than one more distance to add.
What to do instead
Before answering, write out the stages in order (perception, reaction, brake lag, braking) and total them; if the question gives speed and a per-second distance, convert each stage to feet and add, then sanity-check that the total is longer than the sum of the first two stages alone.
On air brake questions the candidate states that the system will hold pressure after the engine is shut off and the parking brake released, or says the low-pressure warning should sound at a pressure far below the real threshold.
Candidates memorise 'the buzzer comes on when pressure is low' as a vague phrase and never anchor it to a number or to the leak-down test, so any plausible figure or any 'it stays charged' answer feels right.
What to do instead
Drill the two numbers as facts: the low air pressure warning must activate before pressure drops below roughly 60 psi, and a system with the engine off and brakes released must not lose more than about 3 psi in one minute (single vehicle). Practise the leak-down sequence out loud until the order of steps is automatic.
During the pre-trip inspection the candidate lists components from memory in a jumbled order, skips the items that are hard to see (brake adjustment, hoses, fifth wheel jaws), and cannot say what a failure of each item would look like.
The inspection is rehearsed as a speech rather than as a physical walk-around, so under test pressure the candidate recites names without linking them to a location on the vehicle or to a reject criterion.
What to do instead
Rehearse in a fixed spatial loop (front, both sides, rear, coupling, in-cab) and for each item say the name, the location, and the pass/fail condition in one sentence; time yourself so the whole loop is repeatable without prompts.
The candidate answers coupling and uncoupling questions without mentioning that the trailer parking brakes must be set and the wheels chocked before the fifth wheel is released, and describes pulling out from under the trailer as a single continuous move.
Coupling is remembered as a sequence of lever pulls, and the safety steps that prevent the trailer rolling or the tractor tipping are treated as optional detail rather than as the reason the sequence has an order.
What to do instead
Learn coupling and uncoupling as numbered checklists with the safety action attached to each step (chock and set trailer brakes before release; tug test after coupling; check jaws and pull the release handle to confirm locked), and state the consequence of skipping each step.
When a question describes a downgrade, the candidate says to downshift after the speed has already built up, or says to use the brakes continuously to hold a steady speed rather than selecting a gear before the descent.
In a car, braking down a hill is normal, so the candidate transfers that habit; the idea that the correct gear is chosen at the top of the grade, before speed rises, is counterintuitive.
What to do instead
Adopt the rule 'gear before grade': identify the gear that holds the desired speed at the crest, engage it before the descent, and use the brakes only in short applications to control any gain; be able to explain why continuous braking overheats the drums and fades the brakes.
The candidate describes backing a tractor-trailer by turning the wheel the same way they want the trailer to go, or claims that a large vehicle can be backed using mirrors alone without getting out to check.
Steering a car in reverse and steering an articulated vehicle in reverse are opposite in effect, and candidates who have only driven cars answer from car intuition; the mirrors feel sufficient because the blind areas are not visible from the seat.
What to do instead
Practise the rule that the bottom of the steering wheel moves in the direction you want the trailer to go, and state explicitly that you must stop, set the brake, and walk back to check clearance when the path is not fully visible or a spotter is not available.
On following-distance questions the candidate gives a fixed number of car lengths regardless of speed, load, or road condition, and does not adjust for a heavy load or wet pavement.
One-second or 'two car lengths' rules learned for cars are easy to recall and feel precise, and the candidate does not connect following distance to the total stopping distance stages.
What to do instead
Answer in seconds and scale them: at least one second for each ten feet of vehicle length at speeds under 40 mph, plus one second at higher speeds, and add more for rain, ice, darkness, or a heavy load; tie the answer back to the fact that a loaded vehicle needs far more distance to stop.
The candidate treats a tire blowout or a brake failure by describing hard braking or shutting off the engine immediately, and does not mention holding the wheel firmly and keeping the vehicle straight while slowing gradually.
Panic responses learned from car driving (slam the brake, kill the ignition) are the first thing that comes to mind, and emergency procedures are studied last, so they are the least rehearsed material.
What to do instead
Memorise the emergency responses as short scripts: for a blowout, hold the wheel firmly, stay off the brake, ease off the accelerator and let the vehicle slow before pulling off; for loss of brakes, downshift, pump the brakes if the system allows, and use an escape route or a safe off-road area; for a stuck accelerator, shift to neutral and brake.
The candidate answers cargo questions by naming the tie-down count but cannot say how the aggregate working load limit relates to the weight of the load, and does not mention that the cargo must be checked again shortly after starting and after driving a while.
Cargo securement is studied as a list of rules rather than as a principle, so the candidate remembers a number but not what it is for and never links it to the re-check requirement.
What to do instead
Learn the principle that the combined working load limit of the tiedowns must be at least half the weight of the article (for the common case) and that the load must be inspected after the first part of the trip and again after driving for a while; be able to state why cargo shifts and what it does to steering and braking.
When a question describes a hazard such as a curve, a railway crossing, or an oncoming vehicle crowding the lane, the candidate answers only with 'slow down' and omits the communication and space-management actions such as covering the brake, checking mirrors, and choosing a lane position or escape path.
Hazard questions are read as speed questions, so the candidate stops at the first correct-sounding action and does not work through the full see-communicate-adjust sequence.
What to do instead
Answer hazard questions with a three-part response every time: what you see and predict, what you communicate (signals, brake lights, lane position), and what you do with speed and space (cover the brake, create a gap, identify an escape route); practise this on written scenarios until the structure is automatic.