cdl practice test questions and answers with verified solutions

cdl practice test questions and answers with verified solutions A railroad crossing is ahead of you and you are hauling hazardous material. When you stop for the crossing, you can stop as far away as ____ feet from the nearest rail. 50 Who is responsible for safely transporting a hazardous material shipment without delay and keeping the shipping papers in the right place? the driver You find an overheated tire during an enroute inspection. If you are hauling hazardous materials, you must: Remove the tire and place it a safe distance from the vehicle. The intent of hazardous materials regulations is to ensure safety, to contain the material, and: to communicate the risk The total transport index of all radioactive material packages in a single vehicle must not exceed ____. 50 You are going to be hauling hazardous materials over a route you do not know well. When should you check the route and get the permits needed for the trip: before starting the trip Which three hazard classes should not be loaded into a trailer that has a heater / air conditioner unit. flammable liquids flammable gas explosives What is the only exception to certification by a shipper? Correct When the shipper is a private carrier of his own product. A truck carrying explosives has crashed with another vehicle. You should not pull them apart until. correct The explosives have been placed at least 200 feet away from the vehicles and occupied buildings. When handling packages of explosives, you must: Correct Never use hooks or other metal tools When driving with more than one trailer, which trailer should be the first one behind the tractor? correct Answer: The heaviest trailer You are driving a 100 foot twin trailer combination at 50 mph. The road is dry and the visibility is good. You should keep at least ____ seconds of space ahead of you. Correct Answer: 11 With the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the rig. When you do this, you should hear: Correct Answer: Air escape from the open valve You are driving with double trailers and must use your brakes to avoid a crash. For emergency braking you should: Correct Answer: Use controlled or stab braking Converter dollies: Correct Answer: Often do not have spring brakes The crack the whip effect that troubles trucks with trailers. Which is most likely to tip over: Correct Answer: The rear trailer of a triple You are doing a walk around inspection of a double or triple trailer rig. You should be sure the converter dolly air tank drain valves are ____ and the pintle hook is ____. closed, latched When does the "driver's manual" advise disconnecting the steering axle brakes to help keep the rig straight? Correct Answer: Never If a converter dolly is still under the second trailer and you unlock the pintle hook, what will probably happen? Correct Answer: The dolly tow bar may fly up You are driving with double trailers and must use your brakes to avoid a crash. For emergency braking you should: : Use controlled or stab braking You are visually checking the coupling of a converter dolly to the rear trailer. How much space should be between the upper and lower fifth wheel? none When should you check your mirrors while making a lane change? ...a. After signaling the change b. Right after starting the lane change after completing lane change Which of these statements about managing space to the sides is true? ...Correct Answer: You should avoid traveling next to others when possible Which of these statements about handling of doubles and triples is true? ...Correct Answer: A sudden movement with the steering wheel can result in a tipped over rear trailer How can you be sure you supplied air to a second trailer? ...Correct Answer: Go to the rear of the second trailer and open the emergency line shut off You should check the height of the trailer before connecting a converter dolly to a second or third trailer. The trailer height is right when: ...a. The trailer will be raised slightly when the converter dolly is backed under it. You want to hook your combination to a second trailer that has no spring brakes. To do this without wheel chocks you should: ...Correct Answer: Supply air to the trailer air system with the tractor and then disconnect the emergency line Which of these will result in the best control on curves? d. Slowing to a safe speed before entering the curve, then accelerate slightly during the curve Before you can supply air to the air tanks of a second trailer you need to: c. Open the shut off valves at the rear of both trailers You are coupling a tractor to a semi trailer and have backed up but are not under it. What should you hook up before backing under? Correct Answer: The emergency and service air lines. You have coupled with a semi trailer. In what position should you put the front trailer supports before driving away? Correct Answer: Fully raised with the crank handle secured in its bracket. Air lines on a combination vehicle are often colored to keep them from getting mixed up. The emergency line is ____; the service line is ____. Correct Answer: Red, blue Which of these statements is true? Correct Answer: "bobtail" tractors can take longer to stop than a combination vehicle loaded to the maximum gross weight. You are coupling a tractor and semi trailer and have connected the air lines. Before backing under the trailer, you should: Correct Answer: Supply air to the trailer system, then pull out the air supply knob to lock the trailer brakes. The hand valve should be used: Correct Answer: To test the trailer brakes. The air leakage rate for a combination vehicle (engine off, brakes off) should be no more than ____ psi per minute. Correct Answer: 3 The fifth wheel locking lever is not locked after the jaws close around the kingpin. This means that: Correct Answer: The coupling is not right and should be fixed before driving the vehicle. You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You would expect the trailer brakes to come on and: Correct Answer: The tractor protection valve to close. Semi trailers made before 1975 that are equipped with air brakes: Correct Answer: Often do not have spring brakes. Before you back under a trailer, make sure the: Correct Answer: Trailer brakes are locked. If the service air line comes apart while you are driving a combination vehicle but the emergency line stays together, what will happen right away? Correct Answer: Nothing is likely to happen until you try to apply the brakes the air leakage rate for a combination vehicle (engine off, brakes on) should not Be more than ____ psi per minute. Correct Answer: 4 In normal driving, some drivers use the hand valve before applying the brake pedal to prevent a jackknife. Which of these statements is true? Correct Answer: It should not be done. The driver crosses the air lines when hooking up to an old trailer. What will happen? Correct Answer: If the trailer has no spring brakes, you can drive away, but you will not have trailer brakes. Why should you lock the tractor glad hands (or dummy couplers) to each other when you are not towing a trailer? Correct Answer: It will keep dirt and water out of the lines. The safety catch for the fifth wheel locking lever must be ____ for a coupling to be complete. Correct Answer: Over the locking lever The front trailer supports are up and the trailer is resting on the tractor. Make sure: Correct Answer: Trailer emergency brakes to come on. When backing under a tractor under a trailer you should expect: Correct Answer: Trailer will be lifted slightly when the tractor backs under it. Of the choices below, the first thing to do when a low air pressure warning comes on is: Your Answer: Stop and safely park as soon as possible. The braking power of the spring brakes: Your Answer: Depends on the adjustment of the service brakes. The air compressor governor controls: Correct Answer: When air is pumped into the air tanks. The application pressure gauge shows the driver how much pressure: Your Answer: Is being applied to the brakes. You should not back a tractor under a trailer until the whole air system is: Correct Answer: At normal pressure You are coupling a semi trailer to your tractor but have not yet backed under. The trailer is at the right height when: Correct Answer: It will be raised slightly when the tractor is backed under it. Which part of the kingpin should the locking jaws close around? Correct Answer: The shank When you get ready to back under the semi trailer you should line up: c. Directly in front of the trailer. How should you test the tractor semi trailer connection for security? Correct Answer: Pull gently forward in low gear against the locked trailer brakes, then look at it carefully. When should you use the hand valve to park a combination vehicle? Correct Answer: Never You supply air to the trailer tanks by: Pushing in the trailer air supply valve. Why should you be sure that the fifth wheel plate is greased as required? Correct Answer: To prevent steering problems After you supply air to the trailer, make sure the air lines are not crossed and The trailer brakes are working. This is done by: Correct Answer: Applying and releasing the trailer brakes and listening for brake sounds. There are two things that a driver can do to prevent a roll over. They are: (1) Keep the cargo as close to the ground as possible; and (2): Go slowly around turns. If your truck or bus has dual parking control valves it means that you can use pressure from a separate tank to: Correct Answer: Release the spring brakes to move a short distance. A straight truck or bus air brake system should not leak at a rate of more than ____ PSI per minute with the engine off and the brakes released. Your Answer: 2 If your vehicle has an alcohol evaporator, it is there to: Your Answer: Reduce the risk of ice in air brake valves in cold weather. If you must make an emergency stop, you should brake so that you: Your Answer: Use the hand brake first. Your truck or bus has a dual air brake system. If a low air pressure warning comes on for only one system, what should you do? Your Answer: Stop. Safely park, and continue only after the system is fixed. Which of the following makes the total stopping distance for air brakes longer than that for hydraulic brakes. Correct Answer: Brake lag distance. Of the choices below, the first thing to do when a low air pressure warning comes on is: Your Answer: Stop and safely park as soon as possible. The braking power of the spring brakes: Your Answer: Depends on the adjustment balance When driving down a long steep hill you should: c. Release the brake when you are 5 M.P.H. below your The brake system that applies and releases the brakes when the driver uses the brake pedal is the: Correct Answer: Service brake system. The most common type of foundation brakes found on heavy vehicles is the: Correct Answer: S-cam drum Vehicles with air brakes must have: Correct Answer: An air pressure gauge to show the pressure available for braking. The driver must be able to see a warning that is given before air pressure in the service air tanks falls below: Correct Answer: 60 psi The air compressor governor controls: Correct Answer: When air is pumped into the air tanks. The application pressure gauge shows the driver how much pressure: Correct Answer: 3 psi in one minute To make an emergency stop with air brakes, using the stab braking method, you should: Correct Answer: Brake as hard as you can, get off the brakes when the wheels lock, get back on the brakes when the wheels start rolling again. You should know that your brakes are fading when: Correct Answer: You have to push harder on the brake pedal to control your speed on a downgrade. To check the free play of manual slack adjusters on s-cam brakes you should: Your Answer: Park on level ground, chock the wheels, and release the parking brakes. If the air compressor should develop a leak, what keeps the air in the tanks? Your Answer: The one way check valve Your Answer: The one way check valve ... Modern air brake systems combines three different systems. The are the service brakes, the parking brakes and the: Correct Answer: Emergency brakes. Oil and water usually collect in compressed air tanks. If you do not have an automatic tank drain, when should you drain the air tanks? Your Answer: After every working day. Why drain water from the compressed air tanks? Correct Answer: Water can freeze in cold weather and cause brake failure. Air brake equipped vehicles must have: Correct Answer: A supply pressure gauge. What can legally hold a parking or emergency brake in position for a truck, truck tractor or bus? Correct Answer: Spring pressure Which of these statements about brakes is true. Your Answer: The heavier a vehicle or the faster it is moving, the more heat the brakes have to absorb to stop it. What should you do when your vehicle hydroplanes? Your Answer: Release the accelerator. Which fires can you use water to put out? Correct Answer: Tire fires. Your vehicle is in a traffic emergency and may collide with another vehicle if you do not take action. Which of these is a good rule to remember at such a time? Your Answer: Heavy vehicles can almost always turn more quickly than they can stop. Which of these is a sign of tire failure? a. Steering that feels heavy. b. Vibration. c. A loud bang. Which of these statements about drinking alcohol is true? Your Answer: A few beers have the same effect on driving as a few shots of whisky. Which of these can help you stay alert while driving? Your Answer: Taking short breaks before you are drowsy. Which one of these is not part of the check of the engine compartment done for a pre trip inspection? Correct Answer: Valve clearance. According to the driver's manual, why should you limit the use of your horn? Your Answer: It can startle other drivers. You are traveling down a long, steep hill. Your brakes get so hot that they fail. What should you do? Your Answer: Look for an escape ramp or escape route. How far should a driver look ahead of the vehicle while driving? Your Answer: 12-15 seconds Which of these statements about cargo loading is true? Your Answer: State laws dictate legal weight limits. Which of these statements about marking a stopped vehicle is true? Correct Answer: If a hill or curve keeps drivers behind you from seeing the vehicle within 500 feet, the rear reflective triangle should be moved back down the road to give adequate warning. You are driving a 40 foot vehicle at 45 MPH. Driving conditions are ideal (dry pavement, good visibility). What is the least amount of space that you should keep in front of your vehicle to be safe? Your Answer: 5 seconds The amount of liquid to load into a tank depends on: legal weight limits,The amount of liquid will expand in transit.