Free Colorado CDL practice test online
Take a free Colorado 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 Colorado Division of Motor Vehicles.
CDL knowledge tests are federally regulated, so the passing score in Colorado 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
Requirements before you test
Colorado CDL test requirements
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 Colorado Division of Motor Vehicles is Colorado’s own, and may be stricter than the federal floor. Test length, fees, and scheduling are set by Colorado Division of Motor Vehicles (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 RegistryYou need a Colorado 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 Colorado non-commercial knowledge test runs 25 questions and needs 20 correct, with permits issued from age 15.
Colorado permit practice testWhat you will practice
Build coverage topic by topic.
Each question carries a topic, difficulty, explanation, and source section so your review has context.
Sample questions
5 Colorado CDL practice questions
Try these Colorado 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. With a fully charged system, engine off, and service brakes fully applied, maximum air loss for a single vehicle is:
- A6 psi in one minute
- B2 psi in one minute
- 3 psi in one minute
- D4 psi in one minute
Answer: 3 psi in one minute. Combination vehicles allow up to 4 psi in one minute on the applied test. Excess leakage must be fixed before driving.
Source: Commercial Driver License Manual — Air brakes — leakage rate test
2. Trying to downshift after speed has already built on a grade is dangerous because you may:
- AIncrease engine braking automatically
- BDisable spring brakes
- CAlways get a lower gear easily
- Be unable to shift into a lower gear and lose engine braking
Answer: Be unable to shift into a lower gear and lose engine braking. Select the correct low gear before starting down based on weight, grade, weather, and road conditions.
Source: Commercial Driver License Manual — Mountain driving — gear selection
3. In combination-vehicle terms, offtracking means:
- The rear wheels follow a different (usually shorter inside) path than the front wheels in a turn
- BThe fifth wheel slides freely
- CAir lines cross automatically
- DThe trailer tracks exactly in the tractor’s path
Answer: The rear wheels follow a different (usually shorter inside) path than the front wheels in a turn. Longer vehicles offtrack more. Steer wide enough for the trailer path without swinging into other lanes unsafely.
Source: Commercial Driver License Manual — Combination vehicles — turning
4. Before loading, unloading, or moving a tanker, intake/discharge/cut-off valves must be:
- AWired fully open always
- BLeft randomly open
- In the correct position for the operation
- DRemoved
Answer: In the correct position for the operation. Wrong valve positions cause spills. Also check pipes, hoses, joints, manhole covers, and vents.
Source: Commercial Driver License Manual — Tank vehicles — inspection
5. During a pre-trip inspection of a bus, which items are specific to carrying passengers?
- ALiquid outage and bulkheads
- BFifth-wheel jaws and kingpin
- Emergency exits, handholds, railings, and signalling devices
- DConverter dolly and pintle hook
Answer: Emergency exits, handholds, railings, and signalling devices. Passenger-carrying equipment must work before the trip: exits must open, handholds and rails must be secure, and passenger signals must function.
Source: Commercial Driver License Manual — Passenger 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 Colorado just like everywhere else — the endorsement guide explains how the codes fit together.
The foundation for commercial driving: inspections, space, speed, communication, hazards, and safe operation.
- Pre-trip inspection
- Space and speed management
- Railroad crossings
- Emergency procedures
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
Prepare for safe coupling, inspection, turning, backing, and handling of tractor-trailer combinations.
- Fifth-wheel inspection
- Coupling and uncoupling
- Off-tracking
- Trailer skid prevention
Study hazard communication, shipping papers, placards, loading rules, parking, and emergency response responsibilities.
- Hazard classes
- Placards and labels
- Shipping papers
- Loading and segregation
Learn how liquid surge, outage, bulkheads, and high centers of gravity change vehicle handling.
- Liquid surge
- Outage requirements
- Smooth braking
- Rollover prevention
Practice converter-dolly inspection, coupling order, rearward amplification, and stability principles.
- Coupling sequence
- Converter dollies
- Rearward amplification
- Space management
Prepare to inspect, load, and operate buses while keeping passengers, aisles, and exits safe.
- Vehicle inspection
- Passenger loading
- Emergency exits
- Prohibited practices
Review student loading, danger zones, mirrors, emergency procedures, and special railroad-crossing duties.
- Danger zones
- Student loading
- Mirror use
- Railroad crossings
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Common questions
What this practice can—and cannot—tell you.