If a tractor-trailer is so equipped, the trailer brake hand valve can be used to stop the vehicle from rolling back when being started from a stop.

After changing a tire, you should stop a short distance later to recheck the tightness of the tire's lug nuts.

If the brakes pull to one side or the other when used, it is an indication of brake trouble.

Reduce your speed when traveling on surfaces that provide reduced traction. Reduce your speed by one-half or more when traveling on packed snow.

Backing is always dangerous and should be avoided whenever possible. When parking, look to park in a space that will allow you to pull forward when exiting.

The securement of cargo must be checked before beginning a trip, within the first 50 miles of a trip, and then again every three hours or 150 miles thereafter.

Check each slack adjuster after parking on level ground, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

For safe operation, a commercial motor vehicle needs a tread depth of 4/32 of an inch in every major groove on the front tires, and a tread depth of 2/32 of an inch on other tires.

The brakes in an air brake system use compressed air to function properly.

The air storage tanks in an air brake system store compressed air to be used for braking. They hold enough air for the brakes to still be used several times if the compressor stops working.

In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.

Because air pressure increases with temperature, you should pay special attention to the tire mounting and pressure when traveling in hot weather.

All trailers and converter dollies manufactured on or after March 1, 1998 must have Anti-Lock Braking Systems (ABS).

The leading cause of injury and death in roadway work zones is excessive speed by passing drivers. Lower your speed when driving through a work zone.

The tire load, or the maximum safe weight that a tire can carry at a given pressure, is stated on the side of each tire.

If you see a distracted driver, give them plenty of space and maintain a safe following distance.

Wheels or rims with welding repairs are never safe to use.

During an inspection, ensure that the wheel bearing/seals are not leaking.

Good drivers look down the road at least 12 to 15 seconds ahead of their vehicles. This makes it possible to identify hazards early, when drivers are more likely to have time to respond appropriately.

To travel safely, it is essential that you know what is happening on all sides of your vehicle at all times. Use your mirrors frequently to help you remain aware of your surroundings.