The Gross Vehicle Weight Rating (GVWR) is the value specified by the manufacturer as the loaded weight of a single vehicle.

Do not try to downshift after your speed has already built up. You will not be able to shift into a lower gear. You may not even be able to get back into any gear and all engine braking effect will be lost.

Hitting overhead objects is dangerous. Make sure you always have overhead clearance.

Because you cannot see everything behind your vehicle, backing is always dangerous. Avoid backing whenever you can. When you have to back, here are a few simple safety rules: Start in the proper position, look at your path, use mirrors on both sides, back slowly, back and turn toward the driver's side whenever possible, and use a helper with clear hand signals whenever possible.

Multi-speed rear axles and auxiliary transmissions are used on many vehicles to provide extra gears. You usually control them by a selector knob or switch on the gearshift lever of the main transmission.

Never remove the radiator cap or any part of the pressurized system until the system has cooled. Steam and boiling water can spray under pressure and cause severe burns.

Most good drivers look at least 12 to 15 seconds ahead. That means looking ahead the distance you will travel in 12 to 15 seconds. At lower speeds, that's about one block.

You should always be able to stop within the distance you can see ahead.

In some weather, water or slush collects on the road. When this happens, your vehicle can hydroplane. It's like water skiing--the tires lose their contact with the road and have little or no traction. You may not be able to steer or brake.

High center of gravity means that much of the load's weight is carried high up off the road. This makes the vehicle top-heavy and easy to roll over.

Wet roads can double stopping distance. You must drive slower to be able to stop in the same distance as on a dry road. Reduce speed by about one-third on a wet road.

Steering around the object when it is safe to do is the safest action.

Oil Level: Indicate where dipstick is located and see that oil level is within safe operating range. Engine Compartment Belts Check belts for snugness up to 3/4-inch play at center of belt with no cracks or frays. Hoses: Inspect hoses for condition and leaks. Valve clearance is the incorrect answer.

Escape ramps are made to stop runaway vehicles safely without injuring drivers and passengers.

Hauling liquids in tanks requires special skills because of the high center of gravity and liquid movement.

Most vehicles now have an ABS light on the instrument panel that will light up briefly when the vehicle is started to alert you that the vehicle has ABS, you can check to see if the vehicle was built on or after March 1, 1998, or you can check for wires from your brakes.

Remember, if the vehicle ahead of you is smaller than yours, it can probably stop faster than you can. You may crash if you are following too closely.

Good drivers shift their attention back and forth, near and far.

Before performing the pre-trip inspection on your vehicle, you must review the inspection report made by the previous driver. Only if defects reported earlier have been certified as repaired or not needed to be repaired, should you sign the previous driver's report.

Turning too sharply, not enough weight on the front axle, and over acceleration are all example of how to cause vehicle skids.

The braking effect of the engine is greatest when it is near the governed rpms and the transmission is in the lower gears.

The following are some causes of vehicle fires: Spilled fuel not properly cleaned up; improper use of flares; under-inflated tires and duals that touch; short circuits due to damaged insulation or loose connections; driver smoking in or around the vehicle; improper fueling and loose fuel connections; flammable cargo, improperly sealed or loaded cargo, with poor ventilation.

Emergency braking does not mean pushing down on the brake pedal as hard as you can. That will only keep the wheels locked up and cause a skid. If the wheels are skidding, you cannot control the vehicle.

Special conditions where you should downshift are: before starting down a hill slow down and shift down to a speed that you can control without using the brakes hard, and before entering a curve slow down to a safe speed and downshift to the right gear before entering the curve.

Linings, or the friction material on brake pads, must not be loose or soaked with oil or grease and must not be dangerously thin. Mechanical parts must be in place, not broken or missing. Leaf springs should not have missing, shifted, cracked, or broken leaf.

In a front-wheel skid, the front end tends to go in a straight line regardless of how much you turn the steering wheel.

Dim your lights within 500 feet of an oncoming vehicle and when following another vehicle within 500 feet.

Axle Weight is the weight transmitted to the ground by one axle or one set of axles

When a vehicle goes around a corner, the rear wheels follow a different path than the front wheels. This is called off-tracking. Longer vehicles will off-track more, the rear wheels of the powered unit will off-track some, and the rear wheels of the trailer will off-track even more.

Inspect the tires more often than usual, or every two hours or every 100 miles when driving in very hot weather.

Brake linings must not be loose or soaked with oil or grease, and must not be dangerously thin, broken, or missing.

An ABC fire extinguisher is a multi-purpose extinguisher and usually uses dry chemicals.

Currently, there are no federal regulations governing the height of splash guards. Each state is free to issue its own regulations, and those regulations vary from one state to another.

BAC is determined by the amount of alcohol you drink, how fast you drink, and your weight.

Alcohol impairs muscle coordination, reaction time, depth perception, and night vision. It also affects the parts of the brain that control judgment and inhibition. These effects mean increased chances of a crash and chances of losing your driver's license. Accident statistics show that the chance of a crash is much greater for drivers who have been drinking than for drivers who have not.

Protect the accident area: if your vehicle is involved in the accident, try to get it to the side of the road, if you're stopping to help, park away from the accident, put on your flashers, and set out reflective triangles to warn other traffic.

You should check your mirrors every 8 to 10 seconds to know what is going on around your vehicle at all times.

Retarders help slow a vehicle, reducing the need for using your brakes. They reduce brake wear and give you another way to slow down.

The following are some causes of vehicle fires: spilled fuel, improper use of flares, under-inflated tires, duals that touch, short circuits, loose connections, improper fueling, loose fuel connections, flammable cargo that is improperly sealed or loaded cargo or has poor ventilation.

If the vehicle has hydraulic brakes, pump the brake pedal three times. Then apply firm pressure to the pedal and hold for five seconds. The pedal should not move. If it does, there may be a leak or other problem.