The CDL, the Test and the Law
What the General Knowledge test is and what 80 percent means, which of the two live CDL manuals your state is giving and what actually differs between them, which class of licence the two weight ratings require and why a tractor pulling a light trailer is not Class A, every endorsement and restriction letter including the one that means two different things, the learner permit and the entry-level training you must now complete before the skills test, what takes a licence away, and the two hours-of-service clocks that run at different rates.
Open the licence guideDriving the Vehicle
The three separate legal duties people collapse into "the pre-trip", where the 419 feet at 55 mph actually goes and which part of it obeys the square law, brake fade and how to come down a grade, how much space to keep in six directions, why low beams reach 250 feet and what follows from that, traction and the two kinds of skid, what makes a hazard readable before it becomes an emergency, where the warning triangles go, and the two cargo securement rules that have to be satisfied independently of each other.
Open the driving guideThe Quizzes
In the order the guides cover them. Each one stands on its own — start wherever the subject interests you.
Licence, Law and Hours
Which of the two live CDL manuals your state is giving, which class the two weight ratings actually require, every endorsement and restriction letter, the permit and the training you must now have first, disqualifications, and the two HOS clocks.
Control and Safe Driving
Where the 419 feet at 55 mph goes and which part of it obeys the square law, downgrades and brake fade, space in six directions, the limits of your own headlights, the two kinds of skid, and what to do with no room left to stop.
Inspection and Cargo
The three separate inspection duties people collapse into one, what puts a vehicle out of service, coupling and the fifth wheel, why axle limits bind independently of the gross, and the two securement rules that must both be satisfied.
Each quiz expands one part of a reference guide into six themes, and each set runs to the length its material justifies rather than to a round number. Options are reshuffled every time you start, and every set was checked against all the others so no question is asked twice. One deliberate constraint runs through all of them: answer length carries no signal in either direction. Across all 140 questions the correct answer is the longest option 21 percent of the time and the shortest about as often, which is what chance would give you. Guarding only against the longest answer is how you end up with a set where picking the shortest wins instead.
The real questions are AAMVA's and the bank is confidential. What is public is the CDL manual your own state hands you, and the federal regulations behind it — and the test is written from those, which is why every answer here carries its citation. Get your state's current manual and read Sections 1, 2 and 3. Two versions are in circulation and states may offer either or both, so check the date on anything you study: this subject has more out-of-date material online than any other on this site. Nothing here satisfies the entry-level driver training requirement, which must come from a provider on the FMCSA Training Provider Registry.