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Louisiana General Knowledge CDL Practice Test

Below are 25 exam-style questions for the Louisiana General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the Louisiana Office of Motor Vehicles. 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.

Heads up: this is a study tool, not a graded exam. Cover the answer with your hand or a sheet of paper for an honest practice run, then re-read the explanations for any questions you missed. Aim for 22 out of 25 or better, three times in a row, before scheduling the real exam.
Question 1 of 25
Which is true about communicating in heavy traffic?
  • A Honk loudly to warn other drivers
  • B Make eye contact only when stopped
  • C Never communicate; just drive
  • D Tap the horn lightly or flash lights to signal your presence
Correct answer: D
A light tap of the horn or a brief headlight flash communicates your presence without startling others. A loud, prolonged horn can provoke aggressive responses.
Question 2 of 25
When approaching a steep downgrade, the basic safe-driving rule is:
  • A Select a lower gear before starting down
  • B Use the parking brake intermittently
  • C Coast in neutral
  • D Stay in high gear
Correct answer: A
Get into a low gear before the descent so the engine helps hold the vehicle back.
Question 3 of 25
Which is true about driving in fog?
  • A Use high-beam headlights for maximum visibility
  • B Use the four-ways while in motion at highway speed
  • C Drive faster to get out of the fog quickly
  • D Use low-beam headlights and slow down
Correct answer: D
High beams reflect off fog and reduce visibility. Slow down and use low beams or fog lamps if equipped.
Question 4 of 25
Black ice is most likely on:
  • A Gravel surfaces
  • B Roads in direct sunlight
  • C Concrete pavement only
  • D Bridges and overpasses
Correct answer: D
Bridges and overpasses freeze first because cold air circulates above and below them. They are the most-asked test scenario for sudden ice.
Question 5 of 25
A driver should secure cargo so it:
  • A Is loaded in the order it will be delivered
  • B Looks neat from the outside
  • C Fills the trailer floor edge to edge
  • D Cannot shift on stops, starts, or turns and is within axle weight limits
Correct answer: D
The legal standard is securement against forces during normal driving conditions plus an emergency stop, and within axle and total weight limits.
Question 6 of 25
Stopping distance is made up of:
  • A Speed times weight
  • B Brake-lag distance only
  • C Perception distance + reaction distance + brake-lag distance + braking distance
  • D Reaction distance only
Correct answer: C
Total stopping distance has four parts. Air brakes add a brake-lag distance not present in hydraulic systems.
Question 7 of 25
Which is true about driving in mountains?
  • A Engine braking helps keep speed under control
  • B Heavy vehicles can slow down sharply on grades
  • C Brakes alone are not designed to hold a heavy vehicle on a long downgrade
  • D All of the above
Correct answer: D
Mountain driving combines all three. Use of low gears, engine braking, and short, moderate service-brake applications is the safe combination.
Question 8 of 25
A CDL is required to operate a single vehicle with a GVWR of:
  • A 20,000 lbs or more
  • B 40,000 lbs or more
  • C 26,001 lbs or more
  • D 10,001 lbs or more
Correct answer: C
Single vehicles at or above 26,001 lbs GVWR (Class B) require a CDL. Class A applies to combinations at or above 26,001 lbs GCWR with a trailer over 10,000 lbs.
Question 9 of 25
When the road is slippery, you should:
  • A Increase following distance
  • B Slow down
  • C Make smooth steering and braking inputs
  • D All of the above
Correct answer: D
Slippery roads require all three: more cushion, smoother inputs, and lower speed.
Question 10 of 25
When driving at night, you should adjust speed so that you can stop within:
  • A Half the range of your low-beam headlights
  • B The range of your low-beam headlights
  • C The full range of high-beam headlights when in use
  • D Whatever speed feels safe
Correct answer: B
Always be able to stop within the distance you can see. At night with low beams, that's typically about 250 feet.
Question 11 of 25
When should you do an en-route inspection?
  • A Only if a warning light comes on
  • B Within the first 25 miles, then about every 150 miles or every 3 hours
  • C Only when the load is hazardous
  • D At the end of the trip
Correct answer: B
The FMCSA model manual recommends a check within the first 25 miles to catch loose cargo or under-inflated tires that have warmed up, then about every 150 miles or 3 hours, and any time you stop.
Question 12 of 25
A driver who has lost the ability to safely brake the vehicle on a downgrade should:
  • A Coast in neutral
  • B Shift into reverse
  • C Look for an escape ramp
  • D Use the parking brake hard
Correct answer: C
Long downgrades have escape ramps for runaway trucks. Use them. Coasting in neutral is illegal in many states and worsens the problem.
Question 13 of 25
A controlled braking technique means:
  • A Pumping the brakes hard and fast
  • B Locking the wheels
  • C Coasting in neutral
  • D Applying the brakes as hard as possible without locking the wheels
Correct answer: D
Controlled braking applies brakes hard but stops short of wheel lock-up. With ABS, you can simply press and hold full pressure.
Question 14 of 25
A driver's blood-alcohol concentration (BAC) of 0.04% or higher while operating a commercial motor vehicle is:
  • A Considered driving under the influence for CDL purposes
  • B Allowed if the driver feels fine
  • C A traffic violation, but not a CDL disqualification
  • D Allowed off-duty only
Correct answer: A
Federal rules treat 0.04% BAC in a CMV as DUI for CDL purposes — half the typical 0.08% limit for non-commercial drivers.
Question 15 of 25
A driver convicted of a major offense (DUI, leaving the scene, etc.) in a CMV faces:
  • A No federal consequence
  • B A fine only
  • C CDL disqualification for at least one year for a first offense
  • D A warning
Correct answer: C
Major offenses carry a one-year CDL disqualification minimum (three years if hauling hazardous materials), and lifetime for a second.
Question 16 of 25
What does it mean when a road sign says "Bridge formation may freeze before road"?
  • A Bridge surfaces freeze first because of air circulation underneath
  • B Bridges are inspected only in winter
  • C The bridge is closed in winter
  • D The pavement under the bridge is reinforced
Correct answer: A
Cold air around bridges and overpasses cools the deck more quickly than the surrounding road, which is why ice often appears there first.
Question 17 of 25
Cargo that hangs more than 4 feet beyond the back of the vehicle must be marked with:
  • A A green flag
  • B A red flag (or red light at night) at the extreme rear
  • C Yellow tape only
  • D Nothing — federal rules do not require marking
Correct answer: B
Federal rules require a red flag during the day and red lights at night for projecting cargo beyond 4 feet.
Question 18 of 25
GCWR stands for:
  • A Gross Combination Weight Rating
  • B General Carrier Weight Rating
  • C Government Combination Weight Reading
  • D Gross Cargo Weight Rating
Correct answer: A
GCWR is the maximum allowable weight of a power unit plus a towed unit, including all cargo. It determines whether a license is Class A.
Question 19 of 25
Acceleration must be smooth and gradual to avoid:
  • A Engine damage
  • B Annoying passengers
  • C Wasting fuel only
  • D Powertrain wear and possible loss of control on slippery surfaces
Correct answer: D
Quick throttle inputs on slick surfaces can spin the drive wheels and cause a tractor jackknife. Smooth acceleration avoids this and reduces wear.
Question 20 of 25
The maximum allowable on-duty driving time after 8 consecutive hours off duty is:
  • A 10 hours
  • B 14 hours
  • C 16 hours
  • D 11 hours
Correct answer: D
After 10 hours off duty, a property-carrying driver may drive up to 11 hours, within a 14-hour on-duty window.
Question 21 of 25
Engine retarders (Jake brakes) should be turned off when:
  • A In residential areas only because of noise
  • B On any downgrade
  • C Roads are wet, icy, or snow-covered
  • D Driving in dry conditions
Correct answer: C
Retarders can cause drive-wheel skids on slippery surfaces. Turn them off when traction is reduced.
Question 22 of 25
Hours-of-service records are required to be kept by:
  • A No one
  • B The driver, in the form of a logbook or electronic logging device
  • C The dispatcher only
  • D The carrier only
Correct answer: B
Drivers are responsible for accurate hours-of-service records, kept either on paper logs or, for most carriers, on an ELD.
Question 23 of 25
You are driving on a two-lane road and you see a driver about to pull out from a side road. You should:
  • A Cover the brake and slow down
  • B Honk and accelerate
  • C Maintain speed
  • D Move to the right lane
Correct answer: A
Anticipate the worst-case behavior. Cover the brake — keeping your foot just over it — so you can react if they pull out.
Question 24 of 25
Which is true about the use of turn signals?
  • A Signal only at the moment you start turning
  • B Use the four-way flashers instead of signals at intersections
  • C Signal early, signal continuously, and cancel after the turn
  • D Signal only when other vehicles are present
Correct answer: C
The federal model manual specifies signal early, continuously, and cancel after — the same three steps every state CDL test asks about.
Question 25 of 25
When should you use four-way flashers?
  • A Whenever you feel like it
  • B When you are stopped or moving slowly enough to be a hazard
  • C Only at night
  • D Only on the highway
Correct answer: B
Four-ways are for vehicles stopped on or near the road or moving so slowly that they are a hazard.

Study tips for the Louisiana General Knowledge exam

The General Knowledge portion of the Louisiana CDL exam is graded out of the bank of questions the Louisiana Office of Motor Vehicles draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the Louisiana 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 Louisiana 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 General Knowledge.

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 Louisiana Office of Motor Vehicles 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 General Knowledge 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 Louisiana General Knowledge practice test before scheduling the real exam.

Next steps

Missed more than four questions? Re-read the General Knowledge study guide and the matching chapter in the official Louisiana 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 Louisiana Office of Motor Vehicles office.

Already comfortable with this endorsement? Drill another: LA Air Brakes · LA Combination Vehicles · LA Hazardous Materials · LA Passenger · LA School Bus · LA Tank Vehicle · LA Doubles / Triples

New to the CDL process in Louisiana? Read How to apply for a CDL in Louisiana for the document checklist and step-by-step timeline.