On a vehicle with one or more trailers, mirror adjustment can only be checked accurately if the trailers are straight. Mirror adjustment should be checked before the start of every trip.

If your hydraulic braking system will not build up the pressure needed to slow or stop your vehicle, there are a few possible solutions. Try shifting into a lower gear, pumping the brakes, and/or using the emergency brake.

When connecting a converter dolly to a second or third trailer, the trailer height should be correct. It should be slightly lower than the center of the fifth wheel.

The suspension system performs the vital functions of holding up the vehicle and its load while keeping the axles in place. Defects in the suspension are therefore extremely dangerous.

Liquids expand as they get warmer and drivers must allow extra space in a tank to accommodate this expansion. Different liquids expand to different degrees, so drivers must be aware of the outage requirements of the specific load they are carrying.

Rollovers are caused by operators turning too fast. To avoid rolling over, drive slowly on entrance ramps, on exit ramps, and around corners. Avoid making quick lane changes when towing trailers.

While baffles in a tank inhibit forward and backward surge, they do not prevent side-to-side surge. Surge to the sides can cause rollovers.

When stopped on the side of the road, be sure to turn on your vehicle's four-way emergency flashers, especially during times of lowered visibility. Place warning devices within 10 minutes of being stopped.

When backing with a trailer, begin by turning the steering wheel in the direction opposite of the turn. Once the trailer starts to turn, reverse the direction of the steering wheel to follow the trailer.

If transporting chlorine in cargo tanks, a driver must have an approved gas mask in their vehicle.

If you are twice convicted of violating any state law regarding hand-held mobile phone use, your CDL will be disqualified. Consequences will become more severe with subsequent violations.

Texting while driving is even more dangerous than speaking on a phone while driving. In addition to being mentally distracting, texting is also physically distracting.

Packaging can be an indicator of whether or not materials are hazardous. Cylinders and drums are often used to hold and transport hazardous materials.

Ice cream trucks can create hazardous conditions for other drivers because they attract children. Children often do not notice or pay attention to other vehicles on the roadway when running to or from ice cream trucks.

The tractor protection valve keeps air in the trailer's braking system should the trailer break away or develop a leak. A loss of air pressure in the emergency line will cause the tractor protection valve to open and the emergency trailer brakes to activate.