Missouri CDL Practice Test

Not quite. The answer is Higher rpm and lower vehicle speeds

An engine retarder is more efficient at a higher engine rpm and a lower vehicle speed, so it’s important to select the right gear. Select your gear before you start down a hill. You’re more likely to miss a shift if you wait until you’re on the downgrade.

Not quite. The answer is 2019

Electronic stability control (ESC) is a system that helps prevent skids. When the system senses that your vehicle isn't moving in the same direction that your steering wheel is pointing, it automatically applies the brakes on certain wheels selectively to bring the vehicle back under your control. ESC has been required on all Class 7–8 truck tractors and buses (except school buses) since August 1, 2019.

Source: 49 CFR 571.136

Not quite. The answer is The use of alcohol or drugs can lead to a collision or an arrest.

Some prescription drugs can impair your driving abilities. Some drugs can make you drowsy or impair your coordination. Stimulants can impair your concentration and affect your vision. And once the stimulant wears off, you may "crash" (feel even more drowsy and tired than you did before). Take a prescription drug only if your doctor assures you that the drug won't impair your driving abilities.

Not quite. The answer is do both (a) and (c).

If you start to move your vehicle when facing uphill, you need to take steps to keep from rolling back. If your vehicle has a manual transmission, partly engage the clutch before you take your right foot off the brake. Put on the parking brake whenever necessary to keep from rolling back. Release the parking brake only when you have applied enough engine power to keep from rolling back. But if you start your vehicle on level, dry pavement, you're unlikely to roll backward, so these steps are not necessary.

Not quite. The answer is Contain the fire

Before trying to put out the fire, make sure that it doesn’t spread any further.

Not quite. The answer is It can only be paid off by sleeping.

Sleep debt is a dangerous condition in which missing sleep adds up until you risk falling asleep at the wheel unless you get some rest. People are often surprised that getting less than 6 hours of sleep per night triples the risk of an accident. At least 15% of heavy truck crashes are believed to involve driver fatigue. Before each trip, you should get adequate sleep. (According to the Missouri Commercial Driver License Manual, adults need eight to nine hours of sleep to maintain alertness.)

Not quite. The answer is You could get hung up halfway across the tracks.

There may not be much space under your vehicle when it is heavily loaded. This is often a problem on dirt roads and in unpaved yards. If you try to cross a railroad track on a dirt road, your vehicle could get hung up halfway across the tracks. Be very careful when driving low-slung vehicles with little ground clearance to begin with, such as lowboys, car carriers, or moving vans.

Not quite. The answer is You should never remove the radiator cap on a pressurized system until the unit has cooled.

Never remove the radiator cap or any part of the pressurized system until the system has cooled. Steam and boiling water can spray under pressure and cause severe burns. Antifreeze has both a relatively low freezing point and a relatively high boiling point, so it can keep your engine from overheating in warm weather.

Not quite. The answer is Many CMV accidents occur between midnight and 6:00 a.m.

Driving through the night when you would normally be asleep increases your risk of an accident. Many CMV accidents occur between midnight and 6:00 a.m. If you've had less than 6 hours of sleep before you drive, your risk of an accident is tripled. And one study has found that going without sleep for more than 24 hours can impair your coordination and reaction time as much as being legally intoxicated.

Not quite. The answer is You are about to exit the road and need to slow down.

Use your brake lights to warn other drivers that you are preparing to slow down or stop, or there is a hazard ahead for which you'll have to slow down. If you're being tailgated, avoid such tricks as flashing your brake lights. Handle tailgaters in a different way: Keep right and increase your following distance.

Not quite. The answer is one-half.

On a slippery road surface, your vehicle's wheels will have less traction, and the vehicle's braking distance will increase significantly. On wet roads, reduce your speed by about one-third. On snow, reduce your speed by about one-half. On ice, slow down to a crawl and stop driving altogether if possible. (On ice, your vehicle's braking distance may increase tremendously.)

Not quite. The answer is Both of the above answers are correct.

If you must drive through water, slow down, shift into a low gear, and keep applying the brakes gently to prevent water, mud, or other contaminants from getting into the brakes.

Not quite. The answer is the pedal should not move.

To test a vehicle equipped with hydraulic brakes for leaks in the brakes, first pump the brake pedal three times. Next, apply firm pressure to the brake pedal for five seconds. The pedal should not move. If it moves, the brakes may have a leak or some other problem.

Not quite. The answer is the load is properly secured.

You are not responsible for the state of the contents of a sealed container, nor can you inspect those contents. You are only responsible for the safety of the cargo, ensuring that it is balanced, secured, and not overloaded, and does not get in the way of emergency equipment.

Not quite. The answer is Check your mirrors regularly.

To find out what's happening behind and to the sides of your vehicle, check your mirrors frequently. Before driving your vehicle, adjust your mirrors to show parts of your vehicle as well as what's around your vehicle.

Not quite. The answer is Exiting a tunnel

Inside a tunnel, you don't feel the effect of crosswinds pushing you sideways. But once you emerge from the tunnel into an open space, the crosswinds will hit you. If your vehicle is traveling alongside another vehicle, there is some chance that the crosswinds will push one of the vehicles against the other.

Not quite. The answer is against the law.

While you're on duty, you are prohibited from using any drug that could make your driving unsafe. This includes even prescription and over-the-counter drugs (such as cold medicines) that might make you drowsy or otherwise affect your ability to drive safely. However, you may use a drug that your doctor tells you will not affect your safe driving abilities.

Not quite. The answer is Under wet or icy road conditions

Retarders can slow your vehicle on a downgrade so you can avoid straining the service brakes. Many retarders can absorb as much or more horsepower as the engine can develop. But when the drive wheels have poor traction (such as on a slippery surface), some retarders can cause the drive wheels to lock, which can result in a skid. Therefore, you should turn the retarder off whenever the road is wet, icy, or snow covered.

Not quite. The answer is Sleep is the only thing that can overcome fatigue.

Caffeine and other stimulants can increase awareness – for a few hours. But once a stimulant wears off, you can "crash" (feel even more drowsy and tired than you did before the stimulant). The only real cure for fatigue is sleep.

Not quite. The answer is Either you or your co-driver

Under federal regulations, at the end of each day, you must prepare a Driver Vehicle Inspection Report (DVIR) to document any defects you found in your CMV. If you had a co-driver, only one of you needs to sign the DVIR, provided that both of you agree about the defects or deficiencies identified.