Missouri (MO) CDL manual 2026

Practice the manual, chapter by chapter

State manuals are built on the same national model, chapter for chapter. One thing to know from each chapter, then real questions from it to answer — tap an option to check yourself.

1. 1

   Introduction

   Everyone

   You will lose your CDL for life if you use a CMV to commit a felony involving controlled substances.

   How long do you lose your CDL for two serious traffic violations in a three-year period?

   1. AAt least 30 days
   2. BAt least 60 days
   3. CAt least 120 days
   4. DAt least one year

   How quickly must you tell your employer that your license has been suspended?

   1. AWithin two business days
   2. BBefore your next dispatch
   3. CWithin seven days
   4. DWithin 30 days
   This chapter has 25 more questions. Practice them in the app and see your pass chance.
2. 2

   Driving Safely

   Everyone

   If you notice any signs of fatigue, stop driving and go to sleep for the night or take a 15 to 20 minute nap.

   How often should you take a break on a long trip?

   1. AAbout every 100 miles or 2 hours
   2. BAbout every 250 miles or 4 hours
   3. COnly when you begin to feel drowsy
   4. DAbout every 400 miles or 6 hours

   What is the final action of the engine compartment step?

   1. ARecord the fluid levels on the report
   2. BWipe down the dipsticks and stow them
   3. CLower and secure the hood, cab, or door
   4. DStart the engine from the fender step
   This chapter has 290 more questions. Practice them in the app and see your pass chance.
3. 3

   Transporting Cargo Safely

   Everyone

   Too much weight on the steering axle can cause hard steering and can damage the steering axle and tires.

   What can happen to brakes that are forced to work too hard by an overload?

   1. AThey apply more slowly than normal
   2. BThey can fail
   3. CThey wear evenly but faster
   4. DThey pull the vehicle to one side

   When is a high center of gravity most dangerous?

   1. AOn long straight stretches at highway speed
   2. BDuring hard braking from low speed
   3. CWhile backing into a loading dock
   4. DIn curves, or when swerving to avoid a hazard
   This chapter has 26 more questions. Practice them in the app and see your pass chance.
4. 4

   Transporting Passengers

   P endorsement (bus)

   A bus does not have to stop, but must slow down and check, where a policeman or flagman is directing traffic, if a traffic signal is green, or at crossings marked exempt or abandoned.

   Your coach is low on fuel mid-trip and a truck stop is ahead. What is the general rule about refueling while your passengers remain in their seats?

   1. AIt is required so that riders can be counted easily
   2. BIt is fine whenever the stop lasts under ten minutes
   3. CAvoid it unless doing so is absolutely necessary
   4. DIt is allowed if at least one exit door stays open

   Which safety-related parts does the manual say riders sometimes damage?

   1. ABrake pedals, gauges, and the fare box
   2. BAxle seals, hubs, and suspension airbags
   3. CWiper blades, mirrors, and marker lamps
   4. DHandholds, seats, emergency exits, and windows
   This chapter has 98 more questions. Practice them in the app and see your pass chance.
5. 5

   Air Brakes

   Any vehicle with air brakes

   In s-cam brakes, the rotating s-shaped camshaft forces the brake shoes apart and against the inside of the drum.

   How is the cab control for a front brake limiting valve normally marked?

   1. A"On" and "off"
   2. B"Normal" and "slippery"
   3. C"Loaded" and "empty"
   4. D"City" and "highway"

   How do the brake lights come on when you apply the brakes on a vehicle with air brakes?

   1. AAn air-operated electric switch closes when brake air pressure flows
   2. BThe driver must flip a separate brake lamp switch
   3. CA cable from the pedal pulls a mechanical contact closed
   4. DThe application gauge sends a signal to the lamps
   This chapter has 148 more questions. Practice them in the app and see your pass chance.
6. 6

   Combination Vehicles

   Class A

   Keeping cargo low is even more important in combination vehicles than in straight trucks.

   After the fifth wheel jaws lock during coupling, how do you confirm the connection with a tug test?

   1. APull forward gently in low gear with the trailer brakes locked
   2. BBack up firmly once more to reseat the kingpin
   3. CShake the release handle while a helper watches the jaws
   4. DRock the trailer sideways using the steering axle

   When you can choose the direction, toward which side should you back a tractor-trailer?

   1. AThe right side, so the curb can guide the trailer
   2. BWhichever side offers the most open pavement
   3. CThe passenger side, to keep the fuel tank protected
   4. DThe driver's side, where you can see the trailer directly
   This chapter has 118 more questions. Practice them in the app and see your pass chance.
7. 7

   Doubles and Triples

   T endorsement

   Release converter dolly brakes by opening the air tank petcock.

   As you fan down the pressure during a tractor protection valve test, in what pressure range should the trailer air supply control normally pop out?

   1. ABetween 20 and 45 psi
   2. BBetween 85 and 100 psi
   3. CBetween 60 and 75 psi
   4. DBetween 5 and 15 psi

   What must you verify about the light cords when inspecting a set of doubles or triples?

   1. AThey are disconnected at the rear of the last trailer
   2. BThey are routed alongside the safety chains
   3. CThey are firmly seated in the sockets on the trailers
   4. DThey are long enough to reach across two trailers
   This chapter has 98 more questions. Practice them in the app and see your pass chance.
8. 8

   Tank Vehicles

   N endorsement

   Tank vehicle drivers must reduce speed on wet roads because lowered traction combines with liquid surge to make control and stopping harder.

   A tanker driver wants to avoid skids, which are especially dangerous when a liquid load is pushing on the tank. What causes most skids?

   1. ADriving too fast for the road and weather conditions
   2. BWorn steering components that let the front wheels wander
   3. CBrake systems that apply unevenly from one side to the other
   4. DSudden gusts of wind striking the tall sides of the tank

   At a rest stop you notice product dripping from underneath your cargo tank. What should you do?

   1. ADrive slowly to the delivery point so the load is off before repairs
   2. BTighten the nearest fitting and continue the trip if the drip slows down
   3. CKeep the vehicle parked and get the leak handled; never drive a leaking tank
   4. DContinue the trip but stay on rural roads away from heavy traffic
   This chapter has 62 more questions. Practice them in the app and see your pass chance.
9. 9

   Hazardous Materials

   H endorsement

   Placards, labels, and shipping papers implement the communication purpose of the hazmat rules.

   What equipment must a driver hauling chlorine in cargo tanks carry?

   1. AA self-contained breathing apparatus and a spill berm
   2. BAn approved gas mask and a dome cover leak kit
   3. CA chemical suit and an absorbent pillow kit
   4. DA respirator cartridge set and a neutralizing agent

   Which division number covers explosives with a mass explosion hazard?

   1. ADivision 1.5
   2. BDivision 1.1
   3. CDivision 1.3
   4. DDivision 1.6
   This chapter has 234 more questions. Practice them in the app and see your pass chance.
10. 10

    School Buses

    S endorsement

    Position the overhead inside rearview mirror to see the top of the rear window in the top of the mirror and all of the students, including the heads of the students right behind you.

    When should you adjust the outside mirror system on your school bus?

    1. AWhile driving slowly during the first mile of the route
    2. BBefore starting the route, while the bus is safely parked
    3. COnly after a student reports something you failed to see
    4. DAt the first student stop, while the red lights are flashing

    Compared with flat mirrors, what is the main advantage of the convex mirrors mounted on the sides of a school bus?

    1. AThey give a much wider view along the side of the bus than flat mirrors do
    2. BThey show objects at their true size and their actual distance
    3. CThey reveal the area hidden directly behind the rear bumper
    4. DThey remove any need to check the flat mirrors before moving
    This chapter has 98 more questions. Practice them in the app and see your pass chance.
11. 11

    Pre-Trip Vehicle Inspection

    Everyone (skills test)

    Electric Brakes: loss of electrical connection to the trailer will result in total loss of braking and control to the towed unit and can lead to a crash.

    What must be true of the lug nuts on every wheel?

    1. AAll fitted with locking washers
    2. BAll of the same manufacturer
    3. CAll present and not loose
    4. DAll torqued within the past 30 days

    What is the consequence of performing the hydraulic brake check incorrectly on the inspection test?

    1. AA point deduction from the total score
    2. BA warning noted on the score sheet
    3. CAn automatic failure of the test
    4. DA required retest of that item only
    This chapter has 200 more questions. Practice them in the app and see your pass chance.

The official Missouri CDL manual