Minnesota CDL Practice Test

Not quite. The answer is involves releasing the brakes only after the wheels lock up.

In the stab braking method, you fully apply the brakes until the wheels lock. Then you release the brakes. Reapply them as soon as the wheels start to roll again. Repeat. (Note: Since this method involves deliberately locking the wheels, don't use it on a vehicle with antilock brakes. Use controlled braking instead.)

Not quite. The answer is perception distance + reaction distance + braking distance.

Total stopping distance is the sum of your perception distance (how far the vehicle goes from when you see the hazard until your brain processes it), reaction distance (how far the vehicle goes from when your brain orders your foot to take action until your foot actually starts to brake), and braking distance (how far the vehicle continues to travel once you apply the brake).

Not quite. The answer is The short-haul part of intermodal transportation

In intermodal transportation, "drayage" refers to short-haul transportation by truck as part of a longer distance. Typically, the truck hauls products from the shipper to a railroad car, where they are loaded onto the railroad car for long-haul shipment elsewhere. Or the reverse: goods transported by rail are then loaded onto a truck for "last-mile" delivery. "Dunnage" is all the loose materials used to support and protect cargo. "Outage" is the extra room allocated to liquid cargo to handle expansion as the liquid warms up.

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 They often make you sleepy. Therefore, they should not be used while driving.

Some cold and allergy medications can cause drowsiness, sedation, or disturbed coordination, which makes them dangerous for CMV operators. If you are unsure about the effects of a particular medication, check the warning label or ask your pharmacist or doctor.

Not quite. The answer is If you have a CB radio, use it to notify the police before you exit your vehicle.

If you have a cell phone or CB radio, the first thing you should do is call for assistance before you get out of your vehicle. If not, first protect the area by turning on your four-way flashers and placing reflective triangles to warn other traffic. Then ask someone to call the police for you.

Not quite. The answer is partly engage the clutch before you take your right foot off the brake.

When you start your vehicle, avoid rolling backward or else you may hit someone behind you. Set 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. If you have a manual transmission vehicle, partly engage the clutch before you take your right foot off the brake. On a tractor-trailer equipped with a trailer brake hand valve, the hand valve can be applied to keep from rolling back.

Not quite. The answer is All of the above

A skid occurs when the tires lose their grip of the road. This can happen in any of four ways: (1) Over-braking: Braking too hard and locking the wheels. Skids can also occur if you use the speed retarder on a slippery road. (2) Over-steering: Turning the wheels more sharply than the vehicle can turn. (3) Over-acceleration: Supplying too much power to the drive wheels, causing them to spin. (4) Driving too fast: Most serious skids result from driving too fast for road conditions.

Not quite. The answer is Axles

All of a vehicle's axles should be aligned perpendicular (a 90-degree angle) to the centerline of the vehicle. If the trailer axles are not properly aligned, the trailer may drift to one side, a condition commonly known as dog-legging or dog-tracking. At a roadside inspection, your trailer can be placed out of service for misaligned axles (49 CFR 393.207(a)). Another possible cause of dog-tracking is incorrectly adjusted tandems (if the trailer is so equipped).

Not quite. The answer is If the wheels are skidding, you cannot control the vehicle.

In an emergency, avoid hard braking. Hard braking can lock the wheels, which may cause a skid and loss of control. Instead, use stab braking (unless your vehicle has antilock brakes) or controlled braking.

Not quite. The answer is 7 pounds.

One gallon of diesel fuel weighs about 7 pounds, meaning that a full fuel tank in a tractor-trailer can weigh well over 1,000 pounds. Bear this in mind when calculating how your vehicle can remain within legal weight limits.

Not quite. The answer is someone could start and move the truck.

While you are performing the pre-trip inspection, you do not want someone (such as a co-driver) who is unaware of your location to start your vehicle and accidentally injure you.

Not quite. The answer is Driving in a selfish or pushy manner

Aggressive driving is driving in a bold, selfish, or pushy manner, which is dangerous enough. Road rage is even worse: intentionally driving to harm someone or physically assaulting someone in his or her vehicle. Examples of aggressive driving include weaving from lane to lane without signaling, purposely blocking another vehicle from changing lanes, and honking the horn to express annoyance, anger, or frustration. Examples of road rage include deliberately ramming another vehicle and exiting one's vehicle to directly confront another driver. Distracted driving is driving while some distraction takes your attention away from the driving task.

Not quite. The answer is turning on the low-beam headlights.

In bad weather, when visibility is low, you can make your vehicle more visible by turning on its exterior lights. When it's raining or snowing, low beams are preferable to high beams because the bright light of high beams can reflect off precipitation, causing glare.

Not quite. The answer is coach buses

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 Class 7–8 truck tractors and buses (except school buses, perimeter-seating buses, and transit buses) since August 1, 2019.

Source: 49 CFR 571.136

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 Rough acceleration can cause mechanical damage.

When you start your vehicle, make sure you don't roll backward, or else you may hit something behind you. Put on the parking brake whenever necessary to keep from rolling backward. Release the parking brake only when you have applied enough engine power to keep from rolling back. On a tractor-trailer equipped with a trailer brake hand valve, the hand valve can be applied to keep from rolling back. Speed up smoothly and gradually so the vehicle does not jerk. Rough acceleration can cause mechanical damage.

Not quite. The answer is the exhaust system.

In cold weather, carefully check your vehicle's exhaust system for loose parts and for sounds and signs of leaks. A leak in the exhaust system can allow dangerous carbon monoxide (CO) to seep into the cab. A buildup of CO is more likely in cold weather, when you may have the cab windows closed.

Not quite. The answer is watch for oncoming traffic.

To make a right turn, turn slowly to give yourself and others more time to avoid problems. If you must cross into the oncoming lane to make a turn, watch out for vehicles coming toward you. Give them room to go by or to stop. Don't back up for them, however, because you might hit someone behind you.

Not quite. The answer is You should remove ice from the radiator shutters.

In extremely cold weather, very cold air flowing onto the radiator and through the engine compartment can prevent the engine from warming up (and also keep your heater from working well). Radiator shutters or a winterfront restrict this air flow to let the engine warm up. However, don't overdo it. Keep the winterfront partially open or keep the radiator shutters free from ice. If the shutters freeze shut or the winterfront is closed too tightly, the engine may overheat from lack of sufficient air.