Tractor protection controls in older vehicles may be operated by levers instead of knobs. If an air supply control is set in its "normal" position, it is properly set for you to pull a trailer.

Roads are often especially slippery when it first begins to rain. Rainwater forms a slick film when mixed with oil and grease on the road surface that has not yet washed away.

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.

If you remain in neutral for too long while switching gears, you may have difficulty putting the vehicle into the next gear. If this happens, do not try to force the gear shift. Instead, return to neutral, release the clutch, increase the engine speed to match the road speed, and try again.

You must have a CDL with a hazardous materials endorsement to drive a vehicle of any size that is used for transporting hazardous materials.

Regrooved, recapped, or retreaded tires are prohibited on the front wheels of a bus.

When backing up to couple a trailer, you should position the tractor directly in front of the trailer. Trying to couple while backing at an angle could cause the trailer to move and the landing gear to break.

When inspecting your vehicle, you should verify that the safety belt is securely mounted, adjusts, latches properly, and is not ripped or frayed.

Cargo inside a trailer must be secured appropriately to prevent it from shifting in transit.

A vehicle will be slowed down by gravity on any uphill grade. You may need to switch to a lower gear to climb a steep grade.

The posted speed limit on a curve may be safe to be taken by cars, but can still be too fast to be taken by larger vehicles, such as trucks. An operator driving their truck at the posted limit on a curve could cause their vehicle to tip over.

Distractions while driving can be physical (such as reaching for an object), mental (such as making conversation with a passenger), or both (such as holding a phone to send texts). Strategies to help you avoid distracted driving include pre-programming radio stations; planning out your route in advance; avoiding complex or emotionally taxing conversation while driving; adjusting your mirrors before setting out; and not eating, drinking, or smoking while behind the wheel.

The best thing to do when confronted with an aggressive driver is to get out of their way, if possible. Avoid making eye contact, which could further provoke the driver. Ignore any hand gestures made by the driver.

When backing a vehicle with a trailer, you must turn the steering wheel in the direction opposite of where you want to go. Once your trailer starts to turn, you should turn the steering wheel the other way to follow the trailer.

The National Response Center must be notified of any incident that results in death; hospitalization; $50,000 or more in estimated property damage; an evacuation of the general public or closure of a major transportation route/facility for more then one hour; fire, breakage, spillage, or suspected contamination involving radiation, bacteria, or toxins. Additionally, if the carrier judges the situation to be so serious that it should be reported, it should be reported.

If you must back up, it is safest to back toward the driver's side of the vehicle. This way, as the driver, you will have the best possible view of your path of travel.

Driving in fog is always dangerous and should be avoided entirely if at all possible. If you must drive in fog, be sure to turn on your low beam headlights and fog lights, even during the daytime.

The emergency air line (also known as the supply line) has two functions. The first is to supply air to the trailer air tanks, and the second is to control the emergency brakes on combination vehicles.

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 shipper of hazardous materials is responsible for packaging, marking, and labeling the materials properly. It is a good idea for the driver to ensure the materials are properly labeled.