Missouri CDL Practice Exam

These questions are part of the practice quiz. Start practicing

• What is required for driving a vehicle transporting hazardous materials?
• Why is it important to use the parking brake when parking?
• What would likely happen if a driver fails to test the trailer emergency brakes before driving?
• How often should you check your mirrors while driving a commercial vehicle?
• What should a driver do if their vehicle begins to skid?
• Which method is NOT typically used in testing trailer brakes?
• Why should the trailer hand brake not be used to straighten out a jack-knifing trailer?
• What is the consequence of having a BAC over 0.04% while operating a commercial vehicle?
• What is the most important method for seeing the sides and rear of your vehicle?
• Why should you use chocks when parking a trailer without spring brakes?
• What should a driver do if road conditions change unexpectedly?
• What is the initial step to test the low pressure warning signal in a vehicle?
• What action should be taken if someone is following you too closely?
• What part of the steering system connects the steering wheel to the axle?
• Which of the following best describes a driver who is preoccupied with food while driving?
• How can you check if the spring brakes come on automatically?
• In which situation may legal maximum weights not be safe?
• Which federal agency governs the interstate standards for commercial driving?
• What does the term “railroad quiet zone” mean?
• Why is it necessary to drain air tanks?
• What action should a driver take when an intersection light turns yellow?
• When you pull out the trailer air supply control, what is being tested?
• What does Gross Combination Weight Rating (GCWR) indicate?
• How often must a commercial vehicle be inspected for safety?
• Why is it important to make emergency plans when you see a hazard?
• What can be an effect of not distributing cargo weight properly?
• What does the service line in a trailer do?
• How should you test the trailer service brakes?
• What are the three main components of the braking system?
• Where are shutoff valves commonly found?
• How can you identify if a vehicle is equipped with antilock brakes?
• When is it necessary to downshift in an automatic transmission?
• What could happen if the brake pedal sinks when testing hydraulic brakes?
• What is the procedure for testing hydraulic brakes for leaks?
• What might happen if the trailer is too high when you attempt to couple?
• What is black ice?
• What could technically happen to the landing gear if not fully raised?
• When must you recheck your cargo after beginning a trip?
• How can you prevent fatigue while driving a commercial vehicle?
• How should a driver handle a broken fan belt?
• What is the minimum age to apply for a CDL in Missouri?
• Which of the following is a sign of a defect in the suspension system?
• What is the usual maximum driving time for a commercial driver before mandatory rest?
• What is a dual air brake system?
• Which type of trailer requires a Class A CDL?
• Why is it critical for a driver to know their vehicle's height?
• What is a good practice when making turns while towing a trailer?
• What information does a supply pressure gauge provide?
• How does the parking brake assist in starting on a hill?
• What distinguishes aggressive driving from road rage?
• What should you do before testing slack adjusters?
• At what distance should you activate your turn signal when changing lanes on a highway?
• What should be checked regularly on a towing vehicle?
• What should a driver do when they see a school bus with its stop sign extended?
• In a trailer braking system, the trolley valve is used for which function?
• Which of the following is a method to reduce stress while driving?
• How should a driver respond to an emergency vehicle with flashing lights?
• Which braking condition is commonly associated with front wheel brakes?
• Are retarders effective in preventing skidding on slippery roads?
• What action should you take when faced with an aggressive driver?
• What can cause understeering in a commercial vehicle?
• What is the maximum leakage rate for a combination vehicle with the brakes on?
• When should the service line be opened?
• What type of vehicle requires a Class A CDL in Missouri?
• What should a driver do when approaching a roundabout?
• What can happen if the cargo is not properly secured?
• How should you use in-vehicle communications equipment cautiously?
• What is the purpose of a pre-trip inspection?
• Under what circumstances can a driver lose their CDL for a year?
• What should be done to prepare for an upcoming turn on a commercial vehicle?
• What is the needed action for sharp turns while driving a tractor-trailer?
• What is the purpose of a "no zone" in relation to large vehicles?
• What is the most important reason for conducting a vehicle inspection?
• Why should you avoid using the trailer hand valve while driving?
• What may happen if water and oil are allowed to accumulate in the air tanks?
• What should you do if you experience a tire blowout while driving?
• What should a driver do if a load is spilling out of the truck?
• What does an orange triangle with a red border signify on a vehicle?
• What do the "no zones" refer to in regard to commercial vehicles?
• What is the function of the emergency air line in a trailer?
• Is it true that using brakes on a long downgrade is only a supplement to the engine braking effect?
• When driving down a hill, why is it important to be in the proper gear?
• What does a solid yellow line on the road signify?
• Do all vehicles with air brakes need to have a low air pressure warning signal?
• What is the main concern when crossing a bridge with a commercial vehicle?
• Which of the following is essential when engaging the trailer emergency brake?
• What three elements make up total stopping distance?
• What is the purpose of a ‘warning triangle’ in a commercial vehicle?
• How can you identify if a trailer is equipped with anti-lock brakes?
• What does CDL stand for?
• What is the primary function of checking the condition of mirrors during an inspection?
• During a trip, which of the following is NOT a critical item to check?
• When driving a 30ft vehicle at 55mph, how many seconds of following distance should you allow?
• How do you test the tractor protection valve?
• If you swing wide to the left before turning right, what may happen?
• Which two indicators can inform you when to shift gears?
• Which of the following is NOT a requirement for obtaining a CDL?
• What must a CDL driver do if they receive a traffic violation while driving?
• What is the primary purpose of using chocks?
• What is the main purpose of using turn signals?
• What is the minimum number of tiedowns required for any flatbed load?
• What is "jackknifing" in the context of driving?
• What is the key reason for the “12-hour rest rule” for CDL drivers?
• What is important to prevent a vehicle rollover?
• To drive with the trailer, how should you raise the landing gear?
• What type of trailers can potentially get stuck on railroad-highway crossings?
• What is the legal limit for BAC (Blood Alcohol Concentration) for drivers in most states?
• What is the most crucial hand signal that you and your helper should agree upon?
• When should a driver perform brake testing on a trailer?
• What is a "highway hypnosis"?
• How many tiedowns are needed for a 20-foot load?
• What should you do before driving after taking prescription medications?
• What can cause brakes to fade or fail?
• What should you do after turning on electrical power to test the low pressure warning signal?
• Should you look into the back of the fifth wheel to ensure it is locked onto the kingpin?
• When parking on a hill, how should you position your wheels?
• Which instrument is NOT typically checked during a vehicle inspection?
• Why is it important to use a helper when backing a vehicle?
• What can be a consequence of having insufficient weight on the front axle?
• What is the maximum Blood Alcohol Concentration (BAC) allowed for commercial drivers in Missouri?
• Why is it important to check blind spots before changing lanes?
• What should you do if the brakes fail while driving a commercial vehicle?
• What is a recommended tip to avoid becoming a distracted driver?
• Which trailer is most likely to turn over when making a sudden turn while pulling doubles?
• Which of the following indicates that a driver may be distracted?
• What would a driver primarily check when testing the trailer service brakes?
• Why is it necessary to listen for trains at railroad crossings?
• What could indicate that a vehicle's air suspension system is defective?
• What is the definition of a commercial motor vehicle?
• What should be checked during a pre-trip inspection regarding the tires?
• When should a driver check their vehicle's height?
• What is required to drive a commercial vehicle with a hazardous materials endorsement?
• How can you start moving on a hill without rolling back?
• What is a consequence of poorly balanced weight in cargo?
• What should you do if your ABS is not functioning?
• What is the purpose of a load tarping system?
• What is the primary cause of commercial vehicle accidents?
• What is the primary function of a parking brake control in the cab?
• How far ahead should a driver look to ensure safe driving?
• What is the consequence of failing to secure your load properly?
• Why is reflective tape used on commercial vehicles?
• What is the required license class for driving a school bus?
• What is the minimum tread depth required for front tires?
• When should you perform a brake check on your trailer?
• Why is it important to keep the starter switch key in your pocket during a pre-trip inspection?
• What should you do if you experience a tire blowout while driving a commercial vehicle?
• What is one reason for covering cargo on an open bed?
• What is hydroplaning?
• How does a driver know when to take a break during long trips?
• What is the most effective way to avoid an accident on the highway?
• What should you do if you feel drowsy while driving a commercial vehicle?
• What action should be taken when encountering a left turn signal that is red?
• What are the two types of air brakes used in large commercial vehicles?
• If you are away from your vehicle for a short time, do you need to use the parking brake?
• What is the recommended following distance under normal driving conditions?
• Which of the following should be checked the front of the vehicle during a walk-around inspection?
• Under what circumstances can a CDL holder use a hand-held cellphone?
• What should you do to keep your vehicle free from distractions?
• What should you do before driving downhill to ensure safety?
• When backing up a commercial vehicle, who should you rely on primarily?
• What is the primary purpose of using headlights during the day?
• What is the required minimum distance to signal before turning or changing lanes in Missouri?
• What does a solid yellow line on your side of the road mean?
• How often must a CDL holder undergo a medical examination?
• What does the term "gross vehicle weight rating" (GVWR) involve?
• Which behavior can lead to disqualification from holding a CDL?
• What should drivers do when approaching a railroad crossing?
• Which of the following is crucial for avoiding skids while driving?
• How should you brake when driving a tractor-trailer combination with ABS?
• What is the potential consequence of driving a trailer with its landing gear improperly set?
• What is an appropriate action when approaching a construction zone?
• What should you do if the trailer brakes release unexpectedly while parked?
• If you are involved in an accident while operating a commercial vehicle, what must you do?
• What is the correct method to test the trailer emergency brakes?
• What is the meaning of a flashing red light on a school bus?
• What advantage does backing towards the driver's side provide?
• What should you do after releasing the parking brake to check spring brakes?
• What is the minimum tread depth for tires other than the front two?
• What is the end goal of testing the trailer emergency brakes?
• What is the purpose of the trailer air supply control?
• Should you decrease your following distance if someone is following you too closely?
• What is 'off tracking' in driving terms?
• What is the consequence of refusing to submit to a chemical test when suspected of DUI in Missouri?
• When stopped on a divided highway, where should the reflectors be placed?
• What is a benefit of using a helper when backing up a vehicle?
• True or False: Empty trucks have the best braking performance.
• Are front wheel brakes effective under all driving conditions?
• How can you check the movement of slack adjusters?
• What are slack adjusters?
• What does "communicating" mean in the context of safe driving?
• How often should drivers check their cargo during a trip?
• Which of the following statements about blind spots is true?
• What is the recommended action if you see a stop sign?
• Which shut off valves should be closed when preparing to tow?
• What is the main goal of CDL regulations?
• If a vehicle is traveling at twice the speed, how much will the stopping distance increase?
• What is a recommended practice if you must use your phone while driving?
• Which three types of emergency equipment must you carry in your vehicle?
• What is one of the responsibilities drivers have regarding their cargo?
• What skill is crucial for safely navigating a commercial vehicle?
• What does a green traffic light indicate at an intersection?
• How often should air tanks be drained?
• When is it acceptable to exceed the speed limit while driving a commercial vehicle?
• During a roadside inspection, what items will likely be checked?
• How can you minimize the risk of a jackknife situation?
• When should a driver perform the pre-trip inspection?
• Why is it essential to ensure the cargo does not obscure your view?
• What happens to spring brakes when air pressure is removed?
• What is the purpose of pulling out the trailer air supply control?
• After coupling a trailer, how much space should be between the upper and lower fifth wheel?
• What should you do if your commercial vehicle begins to skid?
• How can you test that air flows to all trailers?
• Why is it important to ensure a vehicle does not exceed axle weight limits?
• When should you downshift a vehicle before entering a curve?
• What is the significance of the hand control (trolley valve) in a trailer?
• Why should you park the vehicle in such a way that you can pull forward when leaving?
• What is the maximum allowable leakage rate for a single vehicle with brakes off?
• What is the most critical factor to ensure the safe load of a commercial vehicle?
• Which part is NOT considered a key component of the steering system?
• What must you check before transporting a sealed load?
• When backing a trailer, what is recommended for optimal positioning?
• What is the purpose of the Commercial Driver's License (CDL) program?
• Which of the following actions is unsafe regarding your cargo?
• In terms of alignment, how should a trailer be positioned in relation to the towing vehicle during a turn?
• What should wheel bearing seals be primarily inspected for?
• What action is performed to apply the service brakes on a trailer?
• What is the primary purpose of the pre-trip inspection?
• Which component is utilized to apply the brakes on a trailer during testing?
• At what pressure should the low pressure signal activate in the air tank?
• How many reflective triangles should a vehicle carry for safety?
• What should a driver look for when testing the response of the trailer service brakes?
• How should a driver respond to aggressive drivers?
• What is one sign that indicates a weight station ahead?
• What is the main function of reflective tape on trucks?
• How many hours of continuous driving are allowed before a rest period must be taken?
• What is the best approach when merging onto a freeway?
• What are the two main things to look for when driving ahead?
• What defines a hazard while driving?
• What part ensures the vehicle's steering system operates smoothly?
• What should a driver do if they are being tailgated?
• What role does cargo weight play in vehicle stopping distance?
• How can you determine your following distance in seconds while driving?