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Free Alabama CDL practice test online

Take a free Alabama CDL practice exam online with clear explanations—no sign-up. Coverage includes general knowledge, vehicle systems, combination vehicles, cargo, and endorsements. Then verify current requirements with Alabama Law Enforcement Agency.

CDL knowledge tests are federally regulated, so the passing score in Alabama is the same as everywhere else: 80% correct on every knowledge test. You must also hold a commercial learner’s permit for 14 days before the skills test.

New to the knowledge test? CDL endorsements explained · One-week study plan

Practice coverage
Complete a run to establish your baseline.
600questions
23topics
80%federal pass mark

49 CFR 383.135(a)(1) sets the CDL knowledge-test passing score at 80%. Reaching it here is not a prediction of your official result.

Requirements before you test

Alabama CDL test requirements

80%
Passing score
49 CFR 383.135(a)(1)
14 days
CLP held before skills test
Alabama Law Enforcement Agency
18
Min. age (in-state)
Alabama Law Enforcement Agency
21
Min. age (interstate)
49 CFR 391.11(b)(1)

Commercial licensing is largely federal. Any figure above credited to a 49 CFR section applies in every state — see 49 CFR 383.135(a)(1) and 49 CFR 383.25(e). A figure credited to Alabama Law Enforcement Agency is Alabama’s own, and may be stricter than the federal floor. Test length, fees, and scheduling are set by Alabama Law Enforcement Agency (official source).

Entry-Level Driver Training comes first

Since February 7, 2022, a new Class A or Class B CDL, a class upgrade, or a first passenger, school bus, or hazardous materials endorsement requires training from a provider on the FMCSA Training Provider Registry (49 CFR 380.600). Practice questions are study material and do not satisfy that requirement.

FMCSA Training Provider Registry

You need a Alabama licence first

A commercial learner’s permit only counts if you already hold an ordinary licence from the same state (49 CFR 383.25(a)(2)). The Alabama non-commercial knowledge test runs 30 questions and needs 24 correct, with permits issued from age 15.

Alabama permit practice test
Quick practice
10 balanced questions with feedback after every answer.
Topic review
Focus on one knowledge area before returning to mixed practice.
Exam-style run
Answer the full starter bank before seeing your results.

Sample questions

5 Alabama CDL practice questions

Try these Alabama sample questions now — each shows the correct answer with a plain-language explanation and a source section. The full 600-question bank is in the practice run.

  1. 1. If you discover a cargo leak of hazardous materials, you should:

    • ATouch the material to identify it by feel
    • Identify it from papers/labels/location without touching, keep people away, and communicate with responders
    • CTaste a small amount if labels are missing
    • DDrive to the next scale before stopping

    Answer: Identify it from papers/labels/location without touching, keep people away, and communicate with responders. Many people are injured by contacting leaks. Keep shipping papers ready for emergency personnel.

    Source: Commercial Driver License Manual — Hazardous materials — emergencies

  2. 2. Class 2 compressed-gas cylinders without racks must be:

    • ALaid randomly on the floor
    • Held upright in racks or boxes that keep them from turning over (unless designed for horizontal loading)
    • CStacked on their sides in the cab
    • DTied only with rope through the valves

    Answer: Held upright in racks or boxes that keep them from turning over (unless designed for horizontal loading). A flat floor alone is not enough—secure cylinders upright unless the design allows horizontal stowage with the relief valve in vapor space.

    Source: Commercial Driver License Manual — Hazardous materials — compressed gases

  3. 3. Liquid cargo shifting is often worst when the tank is:

    • APressurized only
    • BCompletely full
    • CCompletely empty
    • Anything other than full or empty (partial loads)

    Answer: Anything other than full or empty (partial loads). Partial loads allow more surge. Freeway ramps and sudden lane changes are prime trouble spots—slow before turns.

    Source: Commercial Driver License Manual — Tank vehicles — partial loads

  4. 4. A B:C fire extinguisher is designed for:

    • ACooling tires with water
    • BWood and paper only
    • Electrical fires and burning liquids
    • DCombustible metals only

    Answer: Electrical fires and burning liquids. B:C units use agents suited to flammable liquids and electrical equipment. An A:B:C unit also covers ordinary combustibles.

    Source: Commercial Driver License Manual — Emergency handling — fire extinguishers

  5. 5. The pressure relief valve on a cargo tank must be:

    • ARemoved for cleaning
    • BSet to the tare weight
    • CSealed shut before each trip
    • Free of obstruction and working correctly

    Answer: Free of obstruction and working correctly. The valve prevents dangerous pressure build-up as the load warms. Blocking it risks rupturing the tank.

    Source: Commercial Driver License Manual — Tank vehicles — vehicle inspection

CDL knowledge areas

Classes and endorsements, organized.

Each area below scopes the reviewed question bank to one knowledge test. The material is federal, so it applies in Alabama just like everywhere else — the endorsement guide explains how the codes fit together.

General knowledge

The foundation for commercial driving: inspections, space, speed, communication, hazards, and safe operation.

  • Pre-trip inspection
  • Space and speed management
  • Railroad crossings
  • Emergency procedures
Practice general knowledge
Air brakes

Understand air-brake components, inspections, warning devices, stopping distance, and controlled braking.

  • Dual air systems
  • Low-air warnings
  • Brake lag and fade
  • Applied-leak and static checks
Practice air brakes
Combination vehicles

Prepare for safe coupling, inspection, turning, backing, and handling of tractor-trailer combinations.

  • Fifth-wheel inspection
  • Coupling and uncoupling
  • Off-tracking
  • Trailer skid prevention
Practice combination vehicles
Hazardous materialsEndorsement H

Study hazard communication, shipping papers, placards, loading rules, parking, and emergency response responsibilities.

  • Hazard classes
  • Placards and labels
  • Shipping papers
  • Loading and segregation
Practice hazardous materials
Tank vehiclesEndorsement N

Learn how liquid surge, outage, bulkheads, and high centers of gravity change vehicle handling.

  • Liquid surge
  • Outage requirements
  • Smooth braking
  • Rollover prevention
Practice tank vehicles
Doubles & triplesEndorsement T

Practice converter-dolly inspection, coupling order, rearward amplification, and stability principles.

  • Coupling sequence
  • Converter dollies
  • Rearward amplification
  • Space management
Practice doubles & triples
Passenger vehiclesEndorsement P

Prepare to inspect, load, and operate buses while keeping passengers, aisles, and exits safe.

  • Vehicle inspection
  • Passenger loading
  • Emergency exits
  • Prohibited practices
Practice passenger vehicles
School busEndorsement S

Review student loading, danger zones, mirrors, emergency procedures, and special railroad-crossing duties.

  • Danger zones
  • Student loading
  • Mirror use
  • Railroad crossings
Practice school bus
Official source hub
Verify current rules before your test.

QuizLane’s starter material points learners back to the agency responsible for licensing in Alabama. Rules and manuals can change; the official agency remains authoritative.

Visit Alabama Law Enforcement Agency
Our accuracy promise
Original wording—not scraped competitor questions
A source section attached to every reviewed item
A correction path when something looks wrong
Read our methodology

Common questions

What this practice can—and cannot—tell you.