While driving, you should continually scan the road ahead to spot potential hazards well in advance. Make emergency plans for how to deal with the hazards in the event that they become dangerous.

When transporting hazardous materials, you may leave your vehicle unattended in a safe haven. A safe haven is a location that has been approved for parking unattended vehicles that are loaded with explosives.

In the event of tire failure, hold the steering wheel firmly. Stay off the brakes and let the vehicle slow down on its own. Once the vehicle has slowed considerably, you should brake very gently, pull off the road, and stop. Check your tires after coming to a complete stop.

After a vehicle is started, the warning lights and buzzers should go out after a few seconds. If the warning signals do not turn off, there may be something wrong with the vehicle.

Knowing proper coupling and uncoupling technique is fundamental to the safe operation of combination vehicles. Improper coupling can be very dangerous.

Stimulant drugs, including caffeine, are not helpful as a way of avoiding fatigue. They may help keep you awake, but will not make you any more alert. Feeling tired is a sign that your body needs sleep, and the only way to properly address it is to stop driving and get some sleep.

If you observe a crash involving an aggressive driver, you should stop a safe distance from the crash scene, wait for police to arrive, and inform them of the aggressive behavior you witnessed.

Driving at night is more dangerous than driving during the day. It is more difficult for drivers to see hazards, the glare of headlights can affect drivers' vision, and there are more fatigued and impaired drivers on the road.

A tank vehicle has a number of items that must be checked during a pre-trip inspection. Refer to the operator's manual for your specific vehicle to ensure that you are checking the vehicle properly. When inspecting any tank vehicle, it is most important to verify that there are no leaks.

When inspecting your vehicle's engine, check the belts for tightness and excessive wear. The amount of "give" that is safe for each belt in a given engine will vary, so learn what is appropriate for your vehicle.

To check your vehicle's lights before a trip, you should set the parking brake, turn off the engine, remove the key from the ignition, and take the key with you. Turn on your low beam headlights and four-way flashers. Get out of the vehicle to make sure the lights are working properly.

To obtain a hazardous materials endorsement, you must pass a security check conducted by the Transportation Security Administration (TSA).

To determine which hazardous materials placards to use, you must know the hazard class of the materials; the amount of hazardous materials being shipped; and the total weight of all classes of hazardous materials in the vehicle.

A vehicle's headlights should be clean during trips. This will ensure that the lights can provide as much light as possible, helping the vehicle to be seen.

Be sure to test the trailer emergency brakes before beginning a trip. After ensuring that the trailer rolls freely, you can test the emergency brakes by pulling out the trailer air supply control, or placing it in the "emergency" position. Pull forward slightly with the tractor and make sure the trailer does not move.

If a substance is being transported in a reportable quantity, the shipper must display the letters "RQ" on the shipping paper and package.

To test the trailer service brakes, you should first ensure that the braking system has a normal air pressure level, then release the parking brake. You should then move the vehicle forward slowly and apply the brakes with the hand control. If the trailer service brakes are working properly, you will feel the brakes activate.

A coolant gauge rising above the highest safe temperature may indicate that there is a problem with the vehicle that could result in engine failure or a fire in the engine. Stop as soon as you safely can and investigate the problem.

Driving with liquids in a partially-filled tank requires special care because liquids are prone to surge when carried in a tank. Liquid surge causes a vehicle's weight to shift.

The easiest way to spot a trailer skid is to use your mirrors. Any time you brake hard, check your mirrors to ensure that your trailer is still in its proper position.