Always downshift before beginning to drive downhill. Take the hill at a speed that does not require you to overuse your brakes.

After a tire has been changed, you should stop a short while later to re-check the tightness of the lug nuts.

In conditions of poor visibility (such as at dawn, at dusk, in rain, or in snow), you should turn on your low beam headlights to make your vehicle easier to see. Do not use your high beams when driving near other vehicles.

When approaching a long downgrade, you should shift into a lower gear then use proper braking techniques. Using the brakes alone could cause them to overheat and fail. The braking power of the engine, which is maximized by being in a lower gear, will be the principal way of controlling your speed on a downgrade.

During a pre-trip inspection, belts in the engine compartment should be checked for tightness and excessive wear.

The "crack-the-whip" effect can cause a trailer to turn over during a lane change. To avoid this phenomenon, drivers should make lane changes at slow, safe speeds.

If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle in a straight line but will still allow you to turn if necessary.

When performing a visual check of coupling devices, you should make sure there is no space between the upper and lower fifth wheel. Ensure that the locking jaws are securely closed around the shank of the kingpin.

Retarders are mechanisms in some vehicles that help slow a vehicle and reduce the need for braking. The four basic types of retarders are exhaust, engine, hydraulic, and electric.

In work zones, you should drive at the posted speed limits. Reduce your speed even further when workers are on or near the road.

When stopping a vehicle with a manual transmission, you should push in the clutch when the engine is close to idle.

Many large vehicles have curved, convex mirrors. Convex mirrors allow drivers to see a wider area than flat mirrors. However, they also make objects seem smaller and farther away than they really are.

On combination vehicles with air brakes, the tractor protection valve keeps air in the tractor or truck brake system, should the trailer develop a bad leak or break away from the tractor.

An Anti-Lock Braking System (ABS) helps to provide additional control during hard braking, but does not necessarily shorten a vehicle's stopping distance.

It is essential that you are aware of what is surrounding your vehicle at all times. You should make a habit of regularly checking your mirrors while driving.

While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.

A vehicle's weight is an important factor affecting its stopping distance. The heavier a vehicle is, the more work the brakes will need to do to bring it to a complete stop.

Always change lanes slowly and smoothly. If there is a vehicle in the other lane that you did not see before beginning to move, they will have more time to react to your vehicle.

When driving, you should scan the road at least 12 to 15 seconds ahead of your vehicle. This will allow you to notice hazards as early as possible, giving you time to react to them appropriately.

If the low pressure warning signal activates while you are driving, it is important that you safely exit the roadway as soon as possible and park your vehicle. If the air pressure gets too low, the brakes will no longer work well enough for you to stop safely.