CDL Combination Vehicles Test practice questions
205 free questions with answers and explanations.
- 51.You are driving a combination vehicle and are approaching a railroad crossing that does not have gates or signals. What is the correct procedure for safely crossing this type of track?Driving Combination Vehicles Safely
- 52.You are driving a combination vehicle through an urban area and notice a child's ball roll into the street ahead. What is your immediate and safest course of action?Driving Combination Vehicles Safely
- 53.During a post-trip inspection of a combination vehicle, you are checking the condition of the trailer's spring brakes. You notice that the parking brake knob on the dash is pushed in, but the trailer's spring brakes are still applied. What is the most likely reason for this discrepancy?Inspecting Combination Vehicles
- 54.A commercial driver is operating a combination vehicle on a two-lane road. The driver is approaching a curve and sees a 'Recommended Speed 35 MPH' sign. The vehicle's current speed is 50 MPH. What should the driver do?Driving Combination Vehicles Safely
- 55.A driver is performing a pre-trip inspection of a combination vehicle. They notice that the electric cord (pigtail) connecting the tractor to the trailer is chafed and has exposed wires. What is the primary risk associated with this condition?Inspecting Combination Vehicles
- 56.A driver is preparing to couple a tractor to a semi-trailer. After backing the tractor under the trailer, raising the landing gear slightly, and connecting the air lines and electrical cable, what is the next critical step to ensure a secure connection before fully raising the landing gear?Combination Vehicle Air Brakes
- 57.A commercial driver is operating a combination vehicle and is planning to exit a highway using an off-ramp. The off-ramp has a posted advisory speed limit of 25 mph. How should the driver approach this situation?Driving Combination Vehicles Safely
- 58.When driving a combination vehicle, you encounter a situation requiring an emergency stop. Your vehicle is equipped with anti-lock braking systems (ABS). What is the recommended braking technique when driving an ABS-equipped combination vehicle in an emergency?Combination Vehicle Air Brakes
- 59.When driving a combination vehicle, you encounter a strong crosswind. How should you adjust your driving technique to maintain control?Driving Combination Vehicles Safely
- 60.You are driving a combination vehicle and need to make a right turn at an intersection. Which of the following is the most critical factor to consider to prevent a 'right turn squeeze'?Driving Combination Vehicles Safely
- 61.You are driving a combination vehicle on a four-lane highway and need to change lanes to the left. Which of the following is the most significant blind spot you must check before initiating the lane change?Driving Combination Vehicles Safely
- 62.During an en route inspection, a driver notices that the trailer's air tanks are not draining water when the drain valves are opened. What is the most likely cause and concern?Inspecting Combination Vehicles
- 63.A commercial driver is operating a combination vehicle on a multi-lane highway and needs to pass a slower-moving vehicle. Which of the following statements accurately describes a critical aspect of safely passing with a combination vehicle?Driving Combination Vehicles Safely
- 64.During a post-trip inspection, a driver observes that the trailer's brake drums are discolored (blueish tint) and smells a strong burning odor. What does this condition most likely indicate?Inspecting Combination Vehicles
- 65.During a pre-trip inspection of a combination vehicle, a driver discovers that the air pressure in the trailer's service brake system is significantly lower than the tractor's. What is the most likely cause of this discrepancy?Driving Combination Vehicles Safely
- 66.A combination vehicle is equipped with an Automatic Slack Adjuster. During a pre-trip inspection, you find that the pushrod stroke on one of the brake chambers exceeds the maximum allowable limit. What is the correct action to take?Combination Vehicle Air Brakes
- 67.During an emergency stop in a combination vehicle equipped with ABS, the driver should:Combination Vehicle Air Brakes
- 68.A commercial driver is operating a combination vehicle and observes a car merging onto the highway from an on-ramp, struggling to match speed. What is the most appropriate defensive driving action for the combination vehicle driver to take?Driving Combination Vehicles Safely
- 69.During a pre-trip inspection, you are checking the trailer's pintle hook. Which of the following conditions would render the vehicle unsafe to operate?Inspecting Combination Vehicles
- 70.Which of the following describes the correct procedure for testing the low air pressure warning system on a combination vehicle?Combination Vehicle Air Brakes
- 71.A driver is performing a pre-trip inspection of a combination vehicle. They notice that the air pressure gauge for the trailer's primary air tank is dropping rapidly after the engine is shut off and the brakes are applied. What is the most likely cause of this issue?Inspecting Combination Vehicles
- 72.You are driving a combination vehicle on a wet, slippery road. To prevent a jackknife, which of the following actions is most critical?Driving Combination Vehicles Safely
- 73.A commercial driver operating a combination vehicle experiences a sudden loss of air pressure in the service brake system. The vehicle is traveling at highway speed. What is the most appropriate immediate action?Driving Combination Vehicles Safely
- 74.A driver is inspecting the air brake system on a combination vehicle. When checking the brake pedal free play, what is the maximum acceptable amount of free play before adjustment is required?Combination Vehicle Air Brakes
- 75.A commercial driver is operating a combination vehicle on a long trip and begins to feel drowsy. What is the most effective and safest action to take?Driving Combination Vehicles Safely
- 76.A commercial driver is preparing to drive a combination vehicle on a long trip. During the pre-trip inspection, they notice that the fifth wheel locking jaws are not fully closed around the kingpin. What is the correct procedure the driver should follow before starting the trip?Driving Combination Vehicles Safely
- 77.During a pre-trip inspection of a combination vehicle, you find that the service line (blue glad hand) on the trailer is severely chafed and worn, exposing the inner reinforcement layers. The emergency line (red glad hand) appears to be in good condition. What is your immediate action?Inspecting Combination Vehicles
- 78.A driver is inspecting the air brake system on a combination vehicle. They notice that the brake chambers on the trailer are operating correctly, and the pushrod travel is within limits. What is the maximum allowable pushrod travel for a Type 30 brake chamber?Combination Vehicle Air Brakes
- 79.When inspecting the cargo securement in a combination vehicle, you notice that a heavy load of machinery is secured with only two tie-downs over the top. The machinery weighs 20,000 lbs. According to federal regulations, what is the minimum aggregate working load limit (WLL) required for the tie-downs to secure this load against movement in all directions?Inspecting Combination Vehicles
- 80.During a pre-trip inspection of a combination vehicle, you notice that the trailer's glad hands are corroded and show signs of air leakage when the brakes are applied. What is the immediate and most appropriate action you should take?Inspecting Combination Vehicles
- 81.A commercial driver is conducting a pre-trip inspection of a combination vehicle. The driver notices that the brake adjustment on one of the trailer's slack adjusters allows more than 2 inches of movement when pulled by hand. What action should the driver take?Driving Combination Vehicles Safely
- 82.What is the primary purpose of the 'spring brakes' in a combination vehicle's air brake system?Combination Vehicle Air Brakes
- 83.A commercial driver is operating a combination vehicle under conditions of strong crosswinds. Which of the following adjustments is most critical for maintaining control?Driving Combination Vehicles Safely
- 84.A commercial driver is operating a combination vehicle and is driving through a construction zone with narrow lanes and concrete barriers. The posted speed limit is reduced to 45 mph. What is the most critical aspect for safe driving in this scenario?Driving Combination Vehicles Safely
- 85.You are conducting a pre-trip inspection of a combination vehicle. When checking the trailer's suspension system, you observe that one of the leaf springs is cracked across its main leaf. What is the correct course of action?Inspecting Combination Vehicles
- 86.During a pre-trip inspection, you find that the air compressor governor on your combination vehicle cuts out at 110 psi. What does this indicate, and what action should you take?Combination Vehicle Air Brakes
- 87.A commercial driver is operating a combination vehicle on a steep downgrade. The driver has downshifted and is using engine braking, but the vehicle is still gaining speed. What is the appropriate next action?Driving Combination Vehicles Safely
- 88.You are driving a combination vehicle on a downhill grade and notice your service brakes are becoming less effective (brake fade). What is the appropriate immediate action?Driving Combination Vehicles Safely
- 89.You are performing a pre-trip inspection of a combination vehicle. You notice excessive free play (more than 2 inches) in the steering wheel. This indicates a serious problem that could lead to:Inspecting Combination Vehicles
- 90.A driver is conducting a pre-trip inspection of a combination vehicle. They observe that the trailer's electrical connector (pigtail) has frayed wires exposing the copper strands. What is the most significant hazard posed by this condition?Inspecting Combination Vehicles
- 91.During a pre-trip inspection of a combination vehicle, you notice that one of the air tanks is actively leaking air, and the air compressor is constantly running. What is the most appropriate immediate action?Combination Vehicle Air Brakes
- 92.A driver is performing a pre-trip inspection on a combination vehicle. After building full air pressure (120 psi), the driver applies the service brakes and holds them for one minute. The air pressure drop should not exceed what amount for a combination vehicle?Combination Vehicle Air Brakes
- 93.You are performing a pre-trip inspection on a combination vehicle. When checking the fifth wheel assembly, you observe that the locking jaws are not fully closed around the kingpin, and there is a visible gap. Which of the following is the most appropriate action?Inspecting Combination Vehicles
- 94.During an en route inspection, you notice that the trailer's tires on one side are significantly hotter to the touch than the tires on the other side. There are no visible signs of tire damage or low pressure. What is the most likely cause of this discrepancy?Inspecting Combination Vehicles
- 95.A driver is conducting a post-trip inspection of a combination vehicle. They observe that one of the trailer's wheel seals is leaking grease onto the wheel and tire. What is the most significant immediate consequence of this issue?Inspecting Combination Vehicles
- 96.You are driving a combination vehicle and are approaching a bridge with a 'Low Clearance: 13 ft 6 in' sign. Your vehicle's total height is 13 feet 4 inches. What is the safest course of action?Driving Combination Vehicles Safely
- 97.A commercial driver is operating a combination vehicle and must navigate a tight urban intersection with pedestrians and other vehicles. What is the most critical defensive driving principle to apply when turning a combination vehicle in such an environment?Driving Combination Vehicles Safely
- 98.A technician is connecting a 'converter dolly' to a second trailer. What is the primary purpose of the converter dolly in a combination vehicle configuration?Combination Vehicle Air Brakes
- 99.A driver is performing a pre-trip inspection of a combination vehicle's air brake system. The driver drains the air tanks and then starts the engine to observe the air compressor's operation. Within what maximum time should the air pressure build from 85 psi to 100 psi in a dual air brake system?Combination Vehicle Air Brakes
- 100.A commercial driver operating a combination vehicle is preparing to make a left turn at an intersection with a traffic island. To avoid striking the island with the trailer, what is the best strategy?Driving Combination Vehicles Safely