Pass your CDL knowledge tests on the first try.
More than 2,000 questions built on the driver manual, mock exams at test length as often as you like, and an air-brake check you run with your own hands.
More than 2,000 practice questions
Pass guarantee. Fail the real test? Full refund!
- Launch price: one payment of $99
- No subscription
- No time limit on access
Your truck. Your air-brake check.
4 in 10 first-timers failed General Knowledge. Nearly 8 in 10 failed Air Brakes.
Every failed attempt costs you another trip, often another fee, and days you are not earning. A school or a carrier does not hold your seat while you retake. This course gets it done the first time, or you get your money back.
California DMV, report RSS-08-225 (2008): 39.5% and 78.3% failed on the first attempt.
Start with the free sampleDo it yourself, right here.
The examiner names a part. You find it and say the check.
298 more drills in the course. See the price
Mock exams at test length, as often as you like.
Against a clock, with the questions you have seen least and the options in a new order. Every mock needs 80% to pass. Last column: mocks before a question comes back.
| Test | Questions | Minutes | Mocks |
|---|---|---|---|
| General Knowledge | 50 | 60 | 15 |
| Air Brakes | 25 | 30 | 7 |
| Combination Vehicles | 20 | 25 | 9 |
| Hazardous Materials | 30 | 35 | 9 |
| Tank Vehicles | 20 | 25 | 3 |
| Doubles and Triples | 20 | 25 | 5 |
| Passenger | 20 | 25 | 5 |
| School Bus | 20 | 25 | 8 |
80 percent is the federal passing score (49 CFR 383.135). States set their own question counts and time limits; ours is a practice clock.
Pass, or your money back.
Fail the official test and we refund the full price. Three conditions.
Read the guarantee terms- 1Pass 3 full-length mock exams of that test before the official one, at 15 seconds a question or more.
- 2Send us the official result, showing your name and that you did not pass, from the email address you bought with. A photo of the result sheet is enough.
- 3Do it within 30 days of the failed test. We refund the full price to the original payment method.
97 lessons, 90 of them to listen to.
2 hours 16 minutes of audio: in the truck, at the gym, on a walk. 104 of the questions prepare you for the skills test that follows the permit.
The lesson marked free plays in full. The others play a short preview.
Show all 97 lessons
01How the knowledge tests work
Which tests you need, how they are scored, and how to use this course.
Included in the full course.
02Vehicle inspection: what to look for
You can name the defects to look for on tires, wheels, brakes, steering, suspension and exhaust, and say what to check during a trip.
Included in the full course.
03The seven-step inspection and brake tests
You can run the seven-step inspection in order, state the gauge readings to expect, and perform the hydraulic, parking and service brake tests.
Included in the full course.
04Basic control of your vehicle
You can start without rolling back, steer and stop smoothly, and back a large vehicle using the six safety rules.
Included in the full course.
05Shifting gears
You can describe double clutching up and down, say when to shift, and explain how automatics and retarders help you slow down.
Included in the full course.
06Seeing ahead, to the sides and behind
You can state how far ahead to look, adjust and check your mirrors correctly, and allow for what a convex mirror does to distance.
Included in the full course.
07Communicating with other road users
You can signal turns, lane changes and slowing correctly, make yourself seen, and place warning devices at the right distances when stopped.
Part of the free sample. Try it now.
08Controlling speed
You can add up total stopping distance, adjust speed for wet, snowy and icy roads, curves and downgrades, and handle hydroplaning.
Part of the free sample. Try it now.
09Managing space around your vehicle
You can work out your following distance in seconds and manage the space behind, beside, above and below your vehicle and in turns.
Included in the full course.
10Seeing hazards
You can tell a hazard from an emergency, recognize the clues on roads and in other road users, and plan your way out in advance.
Included in the full course.
11Distracted driving
You can define the types of distraction, state the federal rules and penalties for hand-held phones and texting, and recognize distracted drivers.
Included in the full course.
12Aggressive drivers and road rage
You can tell aggressive driving from road rage, keep your own stress down, and respond safely when an aggressive driver confronts you.
Included in the full course.
13Driving at night and fatigue
You can state headlight sight distances and the 500-foot dimming rule, handle glare, and recognize and respond to the warning signs of fatigue.
Included in the full course.
14Driving in fog
You can decide when to get off the road in fog and, if you must keep driving, use your lights, flashers, the roadside reflectors and your hearing to stay safe.
Included in the full course.
15Driving in winter
You can name the extra winter vehicle checks, drive correctly on slippery roads and dry out wet brakes after crossing water.
Included in the full course.
16Driving in very hot weather
You can inspect tires and the cooling system for very hot weather, add coolant without getting burned and adjust your driving for heat.
Included in the full course.
17Railroad-highway crossings
You can read every crossing sign and signal, stop at the right distance from the rails and cross the tracks without getting trapped or stuck.
Included in the full course.
18Mountain driving
You can choose a safe speed and the right low gear before a downgrade and use the on-and-off braking method that keeps your brakes from fading.
Included in the full course.
19Emergencies: steering to avoid a crash
You can steer around a hazard, choose the safer direction and leave and re-enter the road without losing control.
Included in the full course.
20Emergencies: quick stops, brake failure and tire failure
You can stop quickly without locking your wheels and respond correctly when your brakes or a tire fail.
Included in the full course.
21Antilock braking systems (ABS)
You can explain what ABS does and does not do, tell whether a vehicle has it and brake correctly with ABS or without it.
Included in the full course.
22Skid control and recovery
You can name the four causes of skids and correct both a drive-wheel skid and a front-wheel skid.
Included in the full course.
23Accident procedures
You can carry out the three basic steps at an accident scene: protect the area, notify authorities and care for the injured.
Included in the full course.
24Vehicle fires
You can name the common causes of vehicle fires, prevent them and fight a fire in the right order with the right extinguisher.
Included in the full course.
25Alcohol, other drugs and driving
You can explain how alcohol builds up in the body and affects driving, and apply the rules on drugs, medicines and illness.
Included in the full course.
26Hazardous materials rules for all drivers
You can recognize hazardous cargo by its placards and shipping papers and tell when you need a hazardous materials endorsement or a tank endorsement.
Included in the full course.
27Inspecting cargo
You can state when cargo and its securing devices must be inspected before and during a trip.
Included in the full course.
28Weight and balance
You can define the main weight terms and explain how overloading, a high center of gravity, and poor balance affect handling.
Included in the full course.
29Securing cargo
You can explain blocking, bracing, the tie-down numbers, header boards, cargo covers, and what to check on a sealed load.
Included in the full course.
30Cargo needing special attention
You can explain why dry bulk, hanging meat, livestock, and oversized loads need extra care and what to do with each.
Included in the full course.
31CDL knowledge and skills tests
You can name the knowledge tests you may need and describe the three segments of the skills test in order.
Included in the full course.
32Medical documentation and self-certification
You can decide whether you drive in interstate or intrastate commerce, excepted or non-excepted, and say when a medical examiner's certificate is required.
Included in the full course.
33Disqualifications: alcohol, major offenses, serious violations
You can state the alcohol limit for commercial drivers and how long you lose your CDL for major offenses and for serious traffic violations.
Included in the full course.
34Disqualifications: out-of-service orders, crossings, hazmat, personal vehicle
You can explain how out-of-service orders, railroad crossing violations, the hazmat background check and violations in your personal vehicle affect your CDL.
Included in the full course.
35Other CDL rules
You can state the one-license rule, the notification deadlines, the fines, and the phone and safety belt rules for commercial drivers.
Included in the full course.
36IRP and IFTA: registration, fuel tax, trip records
You can explain what IRP and IFTA are, which vehicles qualify, and what you must record on each trip.
Included in the full course.
37Air brake parts: making and storing air
You can name the parts that make, store, clean and apply compressed air, and give the pressures at which the governor and the safety valve act.
Included in the full course.
38Gauges, warnings, spring brakes and ABS
You can read the air gauges, say when the low air warning and the spring brakes act, work the parking brake controls and tell whether a vehicle has ABS.
Included in the full course.
39Dual air brake systems
You can explain how a dual air brake system is split, how much pressure to build before driving and what to do when one side loses air.
Part of the free sample. Try it now.
40Inspecting air brakes: belt, slack adjusters, drums
You can check the compressor belt, the slack adjusters and the drums, linings and hoses, and say why an automatic slack adjuster should not simply be adjusted by hand.
Included in the full course.
41The final air brake check
You can carry out the seven parts of the final air brake check in order and give the pressure and time limit for each test.
Included in the full course.
42Stopping with air brakes
You can make normal and emergency stops with air brakes, brake correctly with or without ABS and name the four parts of total stopping distance.
Included in the full course.
43Brake fade, downgrades, low air and parking
You can explain brake fade, brake correctly on a long downgrade, respond to a low air warning and decide when to use or not use the parking brakes.
Included in the full course.
44Rollovers, steering, braking and rail crossings
You can explain what makes a combination roll over, why trailers magnify sudden steering, why empty rigs stop slowly and what to do if you are stuck on railroad tracks.
Included in the full course.
45Trailer skids, wide turns and backing
You can recognize and stop a trailer skid, steer a combination through a turn without running over the curb and back a trailer along a planned path.
Included in the full course.
46Combination vehicle air brakes
You can name each trailer brake control and air line, connect glad hands correctly and explain what happens when the emergency line loses pressure.
Part of the free sample. Try it now.
47Antilock brakes on trailers
You can tell whether a trailer or dolly has ABS, find its malfunction lamp and brake correctly when only part of the combination has ABS.
Included in the full course.
48Coupling a tractor and semitrailer
You can couple a tractor to a semitrailer in the correct order, check that the connection is secure and outline how pintle hook, drawbar and gooseneck hitches are coupled.
Included in the full course.
49Uncoupling a tractor and semitrailer
You can uncouple a tractor from a semitrailer in the correct ten-step order and outline how pintle hook, drawbar and gooseneck hitches are released.
Included in the full course.
50Inspecting a combination vehicle
You can inspect the coupling system and landing gear and carry out the four combination brake checks, including the tractor protection valve test.
Included in the full course.
51Why the hazardous materials rules exist
You can name the three aims of the hazardous materials rules and say what you must know to earn the endorsement.
Included in the full course.
52Who does what: shipper, carrier, driver
You can tell which duties belong to the shipper, the carrier and the driver of a hazardous materials shipment.
Included in the full course.
53Shipping papers, labels, placards and the three lists
You can explain hazard classes, labels, placards and identification numbers, say where shipping papers must be kept and read the main columns of the Hazardous Materials Table.
Part of the free sample. Try it now.
54Shipping paper entries, package markings and placarding
You can check a hazardous materials shipping paper, compare it with the package markings and decide which placards your load needs.
Included in the full course.
55Loading and unloading: the general rules
You can load and secure hazardous materials safely and name the classes covered by the smoking, cargo heater and closed cargo space rules.
Included in the full course.
56Loading rules for specific hazard classes
You can apply the special loading rules for explosives, flammable solids, oxidizers, corrosives, compressed gases, poisons and radioactive materials.
Included in the full course.
57Bulk packaging: marking, loading and unloading
You can tell cargo tanks from portable tanks, read their markings and follow the attendance, grounding and engine rules when loading and unloading.
Included in the full course.
58Parking, attending and routing a placarded vehicle
You can apply the parking distances, the attendance rule, the ban on flares and the route planning rules for placarded vehicles.
Included in the full course.
59On the road: smoking, fuel, tires, papers and railroad crossings
You can follow the smoking, fueling, fire extinguisher and tire rules, keep the right papers within reach and stop correctly at railroad crossings.
Included in the full course.
60Hazardous materials emergencies
You can act correctly at a crash, fire, leak or spill involving hazardous materials and know when and whom to notify.
Included in the full course.
61Hazardous materials glossary: the key terms
You can explain the hazardous materials terms that the rest of the section relies on, such as bulk packaging, cargo tank, consignee and reportable quantity.
Included in the full course.
62Inspecting tank vehicles
You can list what to check on a tank vehicle, starting with leaks, and name the special equipment that must work.
Included in the full course.
63Driving tank vehicles
You can explain high center of gravity, liquid surge, bulkheads, baffles, and outage, and name the three things that decide how much to load.
Included in the full course.
64Safe driving rules for tank vehicles
You can describe how to brake, take curves, judge stopping distance, and avoid skids in a tank vehicle.
Included in the full course.
65Pulling double and triple trailers
You can explain why doubles and triples are less stable and how to steer, look ahead, manage space, and park them.
Included in the full course.
66Coupling twin trailers
You can put the steps for coupling a second trailer with a converter dolly in order and explain the key checks.
Included in the full course.
67Uncoupling doubles and handling triples
You can put the steps for uncoupling a rear trailer and a converter dolly in order, and describe how triples are coupled and uncoupled.
Included in the full course.
68Inspecting doubles and triples
You can list the extra coupling, landing gear, and shut-off valve checks for doubles and triples and state which valves are open and which are closed.
Included in the full course.
69Doubles and triples air brake check
You can carry out the four extra air brake checks for doubles and triples and state the pressure range at which the tractor protection valve control should pop out.
Included in the full course.
70Bus vehicle inspection
You can list what to check on a bus before driving, including the previous driver's report, the emergency equipment, and the interior.
Included in the full course.
71Loading and trip start
You can state the rules for baggage, hazardous materials on a bus, the standee line, and announcements at stops.
Included in the full course.
72On the road with passengers
You can supervise riders, avoid the most common bus accidents, and state the stopping rules for railroad crossings and drawbridges.
Included in the full course.
73After-trip vehicle inspection
You can state when a bus must be inspected after driving and what the written inspection report must contain.
Included in the full course.
74Prohibited practices and brake-door interlocks
You can list the practices a bus driver must avoid and explain what a brake-door interlock does and what it must not replace.
Included in the full course.
75Danger zones and use of mirrors
You can describe the danger zones around a school bus and say what each mirror must show when it is adjusted correctly.
Included in the full course.
76Approaching the stop and loading students
You can make a safe school bus stop in the right order and load students without losing track of any of them.
Included in the full course.
77Unloading students and the post-trip inspection
You can unload students on the route and at school, guide students who must cross the roadway, and finish with a post-trip inspection.
Included in the full course.
78Emergency exit and evacuation
You can decide when a school bus must be evacuated, pick a safe place for the students and carry out the evacuation in order.
Included in the full course.
79Railroad-highway crossings
You can recognize passive and active crossings, read the warning signs and take a school bus across the tracks in the recommended order.
Included in the full course.
80Student management
You can keep your attention on loading and unloading and handle a serious behavior problem on the bus safely.
Included in the full course.
81Antilock braking systems
You can say which vehicles must have ABS, how to brake with it and what to do when the yellow malfunction lamp stays on.
Included in the full course.
82Special safety considerations
You can use strobe lights, handle strong winds, back a school bus only when you must and allow for tail swing.
Included in the full course.
83Inspection test: inside the cab and engine start
You can explain how the vehicle inspection test works and name the cab items and brake checks you must show at engine start.
Included in the full course.
84Inspection test: passenger and school bus items
You can name the extra items you must inspect on a passenger bus and on a school bus.
Included in the full course.
85Inspection test: lights operation check
You can describe how to check every external light and how to direct the examiner during the lights check.
Included in the full course.
86Inspection test: external inspection
You can walk around a vehicle and name what to check at the front, steering axle, side, and rear, and why.
Included in the full course.
87Inspection test: combination vehicles and trailers
You can name what to inspect on air and electric lines, the coupling, and the trailer in a combination vehicle.
Included in the full course.
88Basic control skills test: how it is scored
You can explain the four things scored on the basic control skills test and what causes an automatic failure.
Included in the full course.
89Basic control skills test: the four exercises
You can describe each of the four basic control skills exercises and the limits that apply to it.
Included in the full course.
90On-road test: turns, intersections, lanes, and expressways
You can describe what the examiner looks for in turns, intersections, lane changes, and expressway driving.
Included in the full course.
91On-road test: stops, crossings, and general driving behaviors
You can describe the stop and start, curve, railroad crossing, school bus discharge, and general behaviors the examiner scores.
Included in the full course.
92General Knowledge: the numbers to know
Every figure from the lessons of this test, as cards. Go through them the evening before.
Included in the full course.
93Air Brakes: the numbers to know
Every figure from the lessons of this test, as cards. Go through them the evening before.
Included in the full course.
94Combination Vehicles: the numbers to know
Every figure from the lessons of this test, as cards. Go through them the evening before.
Included in the full course.
95Hazardous Materials: the numbers to know
Every figure from the lessons of this test, as cards. Go through them the evening before.
Included in the full course.
96School Bus: the numbers to know
Every figure from the lessons of this test, as cards. Go through them the evening before.
Included in the full course.
97Where the manual is out of date, and what to answer
You know the points where the commercial driver manual prints a figure that federal law has since changed, and what to do about each.
Included in the full course.
What do I get that a free practice test does not?
- Every answer shows the manual sentence it rests on.
- Every answer key was checked twice against the manual.
- The mock exams change their questions and the order of the options at every sitting.
- Fail the real test and you get your money back.
The whole course for $99.
One payment for every test in the course. No subscription.
Free sample: 5 questions with full explanations, the working air-brake cab and one lesson to listen to. No signup.
- 97 lessons, 90 of them as audio
- 2,054 practice questions, each explained; the ones you miss come back
- Timed mock exams, as often as you like
- 1 simulator and 299 drills you work with your hands
- No time limit on access
Pass guarantee. Fail the real test? Full refund. How it works
Secure checkout by Stripe. If you were charged twice or by mistake, write to us and we refund that charge.
A question before you buy? Write to support@cdlgreenlight.com.
Before you decide.
Who is this for?
Anyone studying for the CDL knowledge tests: the commercial learner's permit tests (General Knowledge, Air Brakes, Combination Vehicles) and the endorsement tests.
Can I try it first?
Yes. 5 questions are free, with no signup. Start the free sample.
How does the pass guarantee work?
Pass 3 full-length mock exams of a test in the course, at a pace of at least 15 seconds a question. If you then fail that official test, send us the official result showing your name within 30 days of the test and we refund the full price. The course keeps count of your passed mocks. Guarantee terms.
Does it cover my state?
Yes. It covers the national manual text that every state's knowledge tests are built on. For state-only details such as fees, see your state's manual.
Is this entry-level driver training (ELDT)?
No. This course prepares you for the written knowledge tests. It is not entry-level driver training (ELDT). For a first hazardous materials endorsement, federal rules require ELDT theory training from a provider on the Training Provider Registry before you take the hazmat knowledge test (49 CFR 380.609 and 383.71).
Is this the official material?
Independent practice material based on the commercial driver manual. Not affiliated with or endorsed by any state licensing agency, AAMVA or the FMCSA.