CDL School

Stopping is not always the safest thing to do in an emergency. When you don't have enough room to stop, you may have to steer away from what's ahead. Remember, you can almost always turn to miss an obstacle more quickly than you can stop.

Explanation: If you stop on a two-lane road carrying traffic in both directions or on an undivided highway, place warning devices within 10 feet of the front or rear corners to mark the location of the vehicle and 100 feet behind and ahead of the vehicle, on the shoulder or in the lane you stopped in.

Explanation: Don't roll back when you start. You may hit someone behind you. If you have a manual transmission vehicle, partly engage the clutch before you take your right foot off the brake. Put on the parking brake whenever necessary to keep it from rolling back. Release the parking brake only when you have applied enough engine power to keep from rolling back 

In some weather, water or slush collects on the road. When this happens, your vehicle can hydroplane. The tires lose contact with the road and have little or no traction. You may not be able to steer or brake. Hydroplaning can occur at speeds as low as 30 mph. Hydroplaning is more likely if tire pressure is low, or the tread is worn.

Basic method for shifting up: release accelerator, push in clutch and shift to neutral at the same time. Release clutch. Let the engine and gears slow down to the rpm required for the next gear. Push in clutch and shift to the higher gear at the same time. Release clutch and press accelerator at the same time.

¾ second to 1 second.

Blocking is used in the front, back, and/or sides of a piece of cargo to keep it from sliding. Blocking is shaped to fit snugly against cargo. It is secured to the cargo deck to prevent cargo movement.

Remember that when the road is slippery, you need much more space to stop, and should keep more space in front of your vehicle.

When people are working on the road, it is a hazard. There may be narrower lanes, sharp turns, or uneven surfaces.

Wedge brakes and disc brakes are less common than s-cam brakes.

To test the parking brake: fasten safety belt, set parking brake, place vehicle into a low gear, and gently pull forward against parking brake to make sure the parking brake holds.

Before you begin backing, work out a set of hand signals that you both understand. Agree on a signal for "stop."

Braking when a tire has failed could cause loss of control. Unless you're about to run into something, stay off the brakes until the vehicle has slowed down. Then brake very gently, pull off the road, and stop.

It takes a typical tractor trailer unit at least 14 seconds to clear a single track and more than 15 seconds to clear a double track.

The total stopping distance is the total minimum distance your vehicle has traveled, in ideal conditions; with everything considered, including perception distance, reaction distance and braking distance, until you can bring your vehicle to a complete stop. At 55 mph, your vehicle will travel a minimum of 450 feet.

What you should do is make a lane change or slow down to prevent a crash if the car suddenly cuts in front of you, and you should not honk or stay close behind the car.

Use either the tachometer or the speedometer and upshift/downshift at the right rpm or road speed.

Because you cannot see everything behind your vehicle, backing is always dangerous. Avoid backing whenever you can. When you must 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.

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

Empty trucks actually require greater stopping distances because an empty vehicle has less traction. It can bounce and lock up its wheels, giving much poorer braking.

Snub braking method is used for steep downhill grades, in this method apply the brakes just hard enough to feel a definite slowdown. When your speed has been reduced to approximately five mph below your "safe" speed, release the brakes. When your speed has increased to your "safe" speed, repeat.

You will lose your CDL for at least one year for a first offense for: Driving a CMV if your blood alcohol concentration is .04% or higher or driving a CMV under the influence of alcohol.

In a front-wheel skid, the front end tends to go in a straight line regardless of how much you turn the steering wheel. On a very slippery surface, you may not be able to steer around a curve or turn.

Air brakes are three different systems: service brake, parking brake, and emergency brake.

Explanation: The gear box is part of the steering system, and other choices are parts of the suspension system.

With the stab braking method, you apply your brakes all the way and release brakes when wheels lock up. 

If an oncoming driver has drifted into your lane, a move to your right is best. If that driver realizes what has happened, the natural response will be to return to their own lane. No one is likely to be driving on the shoulder, but someone may be passing you on the left.

Explanation: Use high beams when it is safe and legal to do so. Use them when you are not within 500 feet of an approaching vehicle. 

The gross combination weight (GCW” is the total weight of the GCWs of each unit of a combination vehicle – truck/tractor and trailer(s) added together.

Do the following to correct a drive-wheel braking skid: stop braking letting the rear wheels roll again and keep the rear wheels from sliding; counter-steer as a vehicle turns back on course, it tends to keep on turning. Unless you turn the steering wheel quickly the other way, you may find yourself skidding in the opposite direction.

Tire problems include: too much or too little air pressure, bad wear, at least 4/32-inch tread depth on front tires, 2/32 inch on all other tires, no fabric should show through the tread or sidewall, cuts or other damage, tread separation, dual tires that come in contact with each other or parts of the vehicle, mismatched sizes, radial and bias-ply tires used together.

If you find yourself being tailgated: avoid quick changes, signal early, reduce speed very gradually, increase your following distance, and don't speed up.

Preventing drowsiness before a trip: Get adequate sleep (8 to 9 hours), prepare route, schedule trips for the hours you are normally awake, drive with a passenger, avoid medications that cause drowsiness.

The B:C type fire extinguisher is designed to work on electrical fires and burning liquids. These are usually the following types of fire extinguishers: Regular Dry Chemical, KCl Dry Chemical, Carbon Dioxide (Dry), Halogenated Agent (Gas).

If the surface is icy, reduce speed to a crawl and stop driving as soon as you can safely do so.

Use windshield washer antifreeze to prevent freezing of the washer liquid.

When driving a loud bang, vibrations, or heavy steering can indicate that a tire has failed.

Explanation: Warn following drivers by flashing your brake lights, don't stop suddenly. If you see a hazard that will require slowing down, warn the drivers behind by flashing your brake lights. At dawn, dusk, in rain, or snow, you need to make yourself easier to see so turn on your lights. 

To know how much space you have, wait until the vehicle ahead passes a shadow on the road, a pavement marking, or some other clear landmark. Then count off the seconds like this: "one thousand-and-one, one thousand-and-two" and so on, until you reach the same spot.

Low air warning devices (buzzer, light, flag) should activate before air pressure drops below 60 psi or level specified by the manufacturer.

Watch for: vehicles that may drift over the lane divider lines or within their own lane; vehicles traveling at inconsistent speeds; drivers who are preoccupied with maps, food, cigarettes, cell phones, or other objects; drivers who appear to be involved in conversations with their passengers.

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

Commercial vehicle must be equipped with 3 red reflective triangles, 6 fuses or 3 liquid burning flares.

Explanation: To drive a vehicle safely, you must be able to control its speed and direction. Safe operation of a commercial vehicle requires skill in accelerating, steering, stopping, and backing safely.

Slow down to a safe speed, and downshift to the right gear before entering the curve. This lets you use some power through the curve to help the vehicle be more stable while turning. It also allows you to speed up as soon as you are out of the curve.

Your CDL will be disqualified after two or more convictions of any state law on texting while operating a CMV. No motor carrier shall allow or require its drivers to engage in texting while driving.

In some vehicles, a control handle on the dashboard may be used to apply the spring brakes gradually. This is called a modulating valve. It is spring loaded, so you have a feel for the braking action. The more you move the control lever, the harder the spring brakes become on. They work this way, so you can control the spring brakes if the service brakes fail.

Before you change lanes, you must first make sure that no vehicles are hiding in your blind spots.

Whether or not you load and secure the cargo yourself, you are responsible for inspecting your cargo, recognizing overloads and poorly balanced weight, knowing your cargo is properly secured and does not obscure your view ahead or to the sides, knowing your cargo does not restrict your access to emergency equipment.

Some vehicles have sight glasses, see-through coolant overflow containers, or coolant recovery containers. These permit you to check the coolant level while the engine is hot. If the container is not part of the pressurized system, the cap can be safely removed, and coolant added even when the engine is at operating temperature.