South Dakota Commercial Driver's License (CDL) Knowledge Tests — Questions and Answers

Question 1: Sample question 9 for Transporting Cargo & Passengers Safely?

Answer A
Answer C
Answer B (Correct answer)
Answer D

Correct answer: Answer B

Without the actual question text and options for this South Dakota CDL sample question, a specific explanation for why 'Answer B' is correct cannot be provided. In the context of a multiple-choice exam, 'Answer B' is designated as the correct response, and its validity would depend on the specific scenario or rule being tested under Transporting Cargo & Passengers Safely.

Question 2: Sample question 6 for Safe Driving Practices & Hazard Awareness?

Answer A
Answer D
Answer B (Correct answer)
Answer C

Correct answer: Answer B

Question 3: When must a bus driver stop at a railroad-highway grade crossing?

Only when the red lights are flashing and a gate is lowered.
Only when transporting more than 15 passengers.
The driver must stop at all railroad crossings. (Correct answer)
Only when a train is visibly approaching.

Correct answer: The driver must stop at all railroad crossings.

Regardless of whether lights are flashing, gates are down, or a train is visible, regulations require all buses carrying passengers to stop at all railroad-highway grade crossings. The stop must be made between 15 and 50 feet before the nearest rail.

Question 4: What is the primary purpose of the 'standee line' on a bus?

To indicate the aisle width required for wheelchair access.
To indicate the forward-most point where passengers may stand to ensure the driver's view is not obstructed. (Correct answer)
To mark the area where passengers are allowed to stand during travel.
To show the driver where to stop the front of the bus at a designated stop.

Correct answer: To indicate the forward-most point where passengers may stand to ensure the driver's view is not obstructed.

The standee line, a line on the floor behind the driver's seat, marks the area that passengers may not occupy while the bus is in motion. This regulation ensures that the driver has a clear field of vision and is free from distractions or crowding by passengers.

Question 5: How many hours may a passenger-carrying CMV driver drive after 8 consecutive hours off duty?

10 hours (Correct answer)
12 hours
8 hours
11 hours

Correct answer: 10 hours

Passenger-carrying drivers are limited to 10 hours of driving time after 8 consecutive hours off duty, differing from the property-carrier rule.

Question 6: A driver performing a pre-trip inspection on a vehicle with air brakes notices that the low-pressure warning light and buzzer activate. At or before what pressure must this warning occur?

100 PSI
20 PSI
90 PSI
55 PSI (Correct answer)

Correct answer: 55 PSI

According to the standardized CDL air brake check procedure, the low air pressure warning devices (light and/or buzzer) must activate at or before the pressure drops to 55 PSI to provide the driver with adequate warning of a potential braking system failure.

Question 7: When must a driver carrying hazardous materials keep the shipping papers in a pouch on the driver's door or on the driver's seat?

Whenever the driver is out of the vehicle. (Correct answer)
At all times while the vehicle is in motion.
Only when loading or unloading the material.
Only when stopped at a weigh station or for inspection.

Correct answer: Whenever the driver is out of the vehicle.

Hazardous materials regulations require that shipping papers be readily accessible to emergency responders. When the driver is not in the vehicle, the papers must be placed on the driver's seat or in the driver's side door pouch to be easily found in an emergency.

Question 8: Short-haul drivers operating within a 150 air-mile radius of their work reporting location may be exempt from which HOS requirement?

The 11-hour maximum driving limit
The 10-hour off-duty requirement
Maintaining a daily Record of Duty Status (log book) (Correct answer)
The 60/70-hour weekly on-duty limit

Correct answer: Maintaining a daily Record of Duty Status (log book)

Qualifying short-haul drivers are exempt from keeping a daily log (RODS) and using an ELD, but they must still comply with driving and on-duty time limits.

Question 9: Which of the following items is NOT a required piece of emergency equipment that must be checked during a pre-trip inspection?

A first-aid kit (Correct answer)
A properly rated and fully charged fire extinguisher
Spare electrical fuses (unless the vehicle uses circuit breakers)
Three red reflective triangles

Correct answer: A first-aid kit

While a first-aid kit is highly recommended, federal regulations specifically mandate that a commercial motor vehicle must be equipped with a fire extinguisher, spare fuses (if applicable), and warning devices for stopped vehicles (such as three reflective triangles).

Question 10: Which of the following is NOT a recommended strategy to manage driver fatigue on long trips?

Getting adequate sleep before beginning a long drive
Taking a short nap of 15–20 minutes when sleepy
Stopping to walk around and stretch
Using energy drinks as a substitute for sleep (Correct answer)

Correct answer: Using energy drinks as a substitute for sleep

Energy drinks and caffeine mask fatigue temporarily but cannot replace actual sleep; relying on them instead of rest increases crash risk.

Question 11: Sample question 6 for CDL Laws, Endorsements & Regulations?

Answer D
Answer B (Correct answer)
Answer A
Answer C

Correct answer: Answer B

Question 12: Under normal driving conditions, what holds the spring brakes in the released position?

Air pressure (Correct answer)
Hydraulic pressure
The driver manually holding a lever
Mechanical linkage from the brake pedal

Correct answer: Air pressure

Spring brakes are a safety feature. They apply automatically when air pressure drops to a low level (20-45 psi). During normal operation, sufficient air pressure in the system overcomes the force of the powerful springs, keeping them caged or released.

Question 13: A driver is operating a truck with a dual air brake system. The low air pressure warning light and buzzer activate. What is the most likely pressure range in one of the systems?

20-45 psi
100-120 psi
Below 60 psi (Correct answer)
80-90 psi

Correct answer: Below 60 psi

The low air pressure warning devices (light, buzzer, or wig wag) are required to activate before the air pressure in either the primary or secondary system drops below 60 psi.

Question 14: Sample question 9 for Safe Driving Practices & Hazard Awareness?

Answer A
Answer C
Answer B (Correct answer)
Answer D

Correct answer: Answer B

Question 15: Sample question 8 for Transporting Cargo & Passengers Safely?

Answer C
Answer A
Answer B (Correct answer)
Answer D

Correct answer: Answer B

Question 16: Sample question 2 for CDL Laws, Endorsements & Regulations?

Answer D
Answer A
Answer B (Correct answer)
Answer C

Correct answer: Answer B

Question 17: A driver is transporting 1,200 lbs of a hazardous material listed on Table 2 of the placarding regulations. What is the placarding requirement for this load?

Placards must be displayed on all four sides of the vehicle. (Correct answer)
A 'DANGEROUS' placard must be used.
Placards are not required as the weight is under 2,000 lbs.
Placards are only required on the front and rear of the vehicle.

Correct answer: Placards must be displayed on all four sides of the vehicle.

According to 49 CFR 172.504, for hazardous materials listed in Table 2, placards are required on each side and each end of the transport vehicle when the aggregate gross weight is 454 kg (1,001 lbs) or more. Since 1,200 lbs exceeds this threshold, the vehicle must be placarded on all four sides.

Question 18: When must a driver re-check their cargo and securing devices after the initial inspection?

After every 5 hours of driving or 250 miles.
Every time the vehicle is refueled.
After driving for 3 hours or 150 miles, and after every break. (Correct answer)
Only at the end of the driving day.

Correct answer: After driving for 3 hours or 150 miles, and after every break.

Federal regulations, which South Dakota follows, require drivers to re-check their cargo and securement systems after the first 50 miles, and then again whenever they change their duty status, after driving for 3 hours, or after driving for 150 miles, whichever comes first.

Question 19: Sample question 5 for Transporting Cargo & Passengers Safely?

Answer D
Answer C
Answer A
Answer B (Correct answer)

Correct answer: Answer B

Question 20: What should be done if a defect is found during inspection?

Report and repair it before driving (Correct answer)
Wait for the next inspection
Tell another driver about it
Ignore it and continue

Correct answer: Report and repair it before driving

Discovering a defect during an inspection means the vehicle may not be safe or legally compliant to operate. It is critical to immediately report the defect to the appropriate personnel and ensure it is repaired before the vehicle is driven. Ignoring defects can lead to accidents, breakdowns, fines, or even legal liabilities, prioritizing safety above all else.

Question 21: Which of the following is a critical safe driving rule specific to tank vehicles due to their high center of gravity and the effects of liquid surge?

Making sudden lane changes to avoid obstacles.
Driving faster than the posted speed limit to minimize time on the road.
Slowing down well before a curve and then accelerating slightly through it. (Correct answer)
Applying brakes hard and late when approaching a stop.

Correct answer: Slowing down well before a curve and then accelerating slightly through it.

Due to a high center of gravity, tankers can roll over at speeds below the posted limit for a curve. The correct technique is to slow to a safe speed before entering the curve and then accelerate gently through it to maintain stability.

Question 22: When descending a long, steep grade, a driver should brake until the vehicle's speed is about 5 mph below the 'safe speed' and then release the brakes. Why is this 'snub braking' technique recommended?

To allow the brake drums to cool and prevent brake fade (Correct answer)
To dry out wet brake linings
To keep the air pressure from dropping too quickly
To ensure the trailer brakes are working harder than the tractor brakes

Correct answer: To allow the brake drums to cool and prevent brake fade

Constant, light pressure on the brakes can cause them to overheat, leading to a dangerous condition called brake fade where they become less effective. The snub braking technique of applying firm pressure for a short time and then releasing allows the brakes to cool between applications, maintaining their stopping power.

Question 23: When inspecting the steering system, what is the maximum amount of acceptable play or 'slack' in a 20-inch steering wheel?

1 inch
3 inches
2 inches (Correct answer)
4 inches

Correct answer: 2 inches

The acceptable limit for steering wheel play is 10 degrees, which translates to approximately 2 inches of movement at the rim of a 20-inch steering wheel. Exceeding this amount could indicate worn steering components and is considered unsafe.

Question 24: A driver is preparing for their pre-trip inspection. If the vehicle is equipped with an alcohol evaporator, what is its primary function?

To clean the air going into the tanks
To reduce the risk of ice forming in air brake valves during cold weather (Correct answer)
To inject alcohol into the fuel system for better combustion
To cool the air compressed by the engine

Correct answer: To reduce the risk of ice forming in air brake valves during cold weather

The alcohol evaporator puts alcohol vapor into the air system. This helps to absorb moisture and reduce the chance that water will freeze in the air brake valves or lines, which could cause brake failure in cold temperatures.

Question 25: During a static air brake leakage test on a single vehicle, what is the maximum permissible pressure drop in one minute after the initial drop?

2 psi (Correct answer)
1 psi
10 psi
5 psi

Correct answer: 2 psi

According to FMCSA regulations for a static leakage test (engine off, brakes released), the pressure drop should not exceed 2 psi per minute for a straight truck or bus. For combination vehicles, the limit is 3 psi per minute.

Question 26: According to federal regulations, which of the following is a prohibited practice when transporting passengers?

Transporting a passenger's properly secured, personal-use oxygen container.
Announcing upcoming stops over a public address system.
Allowing carry-on baggage to be placed on an empty seat.
Refueling the bus in a closed building with passengers on board. (Correct answer)

Correct answer: Refueling the bus in a closed building with passengers on board.

Federal regulations strictly prohibit refueling a bus inside a closed building while passengers are on board due to the significant risk from flammable fumes and potential ignition sources.

Question 27: You are driving a truck with a sealed container load and cannot inspect the cargo inside. What are you still responsible for?

Unsealing the container for a visual inspection before departure.
Verifying the contents of the container item by item.
Making sure the gross weight and axle weight limits are not exceeded. (Correct answer)
Ensuring the seal's number matches the shipping papers.

Correct answer: Making sure the gross weight and axle weight limits are not exceeded.

Even with a sealed load where the contents cannot be inspected, the driver is always responsible for ensuring the vehicle does not exceed the legal gross weight and individual axle weight limits.

Question 28: Which of the following is the most critical rule regarding carry-on baggage on a bus?

Baggage must be stowed in a way that does not block any aisles or emergency exits. (Correct answer)
The driver is only responsible for baggage stored in the overhead compartments.
All carry-on baggage must be small enough to fit on the passenger's lap.
Heavy bags should be stored at the very front of the bus for easy access.

Correct answer: Baggage must be stowed in a way that does not block any aisles or emergency exits.

The highest priority for stowing carry-on baggage is to ensure that it does not create a hazard. All aisles, stairwells, and emergency exits must be kept completely clear at all times to allow for safe movement and rapid evacuation in an emergency.

Question 29: The term 'outage' refers to which of the following when loading a liquid tank?

A power failure in the pumping equipment during loading.
The empty space left in a tank to allow for liquid expansion. (Correct answer)
The process of cleaning a tank after unloading.
The amount of liquid lost due to a minor leak during transit.

Correct answer: The empty space left in a tank to allow for liquid expansion.

Liquids expand when they get warm. 'Outage' is the empty space intentionally left at the top of a tank to accommodate this expansion, preventing spills and dangerous pressure buildup.

Question 30: Sample question 5 for CDL Laws, Endorsements & Regulations?

Answer C
Answer A
Answer B (Correct answer)
Answer D

Correct answer: Answer B

Question 31: You are the driver for a charter bus tour. When is the best time to make announcements regarding safety features, such as the location of emergency exits?

After all passengers have boarded and before the trip begins. (Correct answer)
While passengers are boarding the bus.
Only in the event of an actual emergency.
At the first designated rest stop of the trip.

Correct answer: After all passengers have boarded and before the trip begins.

Safety briefings, similar to those on an airplane, should be conducted before the bus begins to move. This ensures all passengers are present and can give their attention to critical information about emergency exits, fire extinguishers, and other safety procedures before any potential incident occurs.

Question 32: According to the Segregation Table for Hazardous Materials (49 CFR 177.848), which of the following material combinations is strictly forbidden to be loaded, transported, or stored together on the same vehicle?

Division 1.1 (Explosives) and Division 1.5 (Very Insensitive Explosives)
Class 7 (Radioactive) and food materials
Division 4.2 (Spontaneously Combustible) and Class 8 (Corrosive) liquids (Correct answer)
Class 8 (Corrosives) and Class 3 (Flammable Liquids)

Correct answer: Division 4.2 (Spontaneously Combustible) and Class 8 (Corrosive) liquids

The Segregation Table at 49 CFR 177.848(d) indicates with an 'X' that Division 4.2 materials and Class 8 liquids may not be loaded, transported, or stored together. This is because their interaction could be dangerously reactive.

Question 33: Which of the following components is responsible for stopping the air compressor from pumping air when the storage tanks reach their maximum pressure?

The safety valve
The slack adjuster
The brake pedal
The air compressor governor (Correct answer)

Correct answer: The air compressor governor

The air compressor governor controls when the air compressor pumps air. It stops the compressor (cuts out) when the tank pressure reaches the specified maximum (typically 125-140 psi) and allows it to start pumping again (cuts in) when the pressure drops to around 100 psi.

Question 34: A driver is preparing to unload a placarded load of Class 3 (Flammable Liquid). According to 49 CFR 177.834, what specific action is prohibited within 25 feet of the vehicle during this process?

Using a two-way radio.
Smoking or having any open flame. (Correct answer)
Leaving the vehicle unattended.
Listening to the vehicle's stereo.

Correct answer: Smoking or having any open flame.

Regulation 49 CFR 177.834(c) explicitly forbids smoking on or about any motor vehicle while loading or unloading any Class 3 (flammable liquid) materials. This rule is in place to prevent ignition of flammable vapors.

Question 35: Which of the following descriptions on a hazardous materials shipping paper is in the correct order according to regulations?

Gasoline, 3, UN1203, PG II
UN1017, Chlorine, 2.3, PG I (Correct answer)
Corrosive Liquid, 8, UN1760
UN1993, Flammable Liquid, n.o.s., 3, PG III

Correct answer: UN1017, Chlorine, 2.3, PG I

According to 49 CFR 172.202, the basic description of a hazardous material on shipping papers must be in a specific sequence: (1) Identification Number, (2) Proper Shipping Name, (3) Hazard Class or Division, and (4) Packing Group. 'UN1017, Chlorine, 2.3, PG I' is the only option that follows this mandatory sequence.

Question 36: When should a driver perform a vehicle inspection?

Only if there is a problem
Only once a week
Before, during, and after each trip (Correct answer)
Only in winter

Correct answer: Before, during, and after each trip

Commercial drivers are required to perform thorough vehicle inspections before each trip to ensure the vehicle is safe and compliant. During the trip, ongoing checks (e.g., monitoring gauges, listening for unusual noises) help identify issues as they arise. A post-trip inspection documents any new defects or maintenance needs, ensuring the vehicle is ready for its next use. This comprehensive approach maximizes safety and reliability.

Question 37: Which of the following drivers is generally required to use an Electronic Logging Device (ELD) under FMCSA rules?

A driver required to keep Records of Duty Status (RODS) under HOS rules (Correct answer)
A driver who always operates within 100 air-miles of the home terminal
A driver transporting non-hazardous freight only
A driver with fewer than 2 years of CDL experience

Correct answer: A driver required to keep Records of Duty Status (RODS) under HOS rules

ELDs are required for drivers who must maintain Records of Duty Status; drivers exempt from keeping RODS (such as qualifying short-haul drivers) are also generally exempt from ELDs.

Question 38: Sample question 7 for Transporting Cargo & Passengers Safely?

Answer A
Answer C
Answer D
Answer B (Correct answer)

Correct answer: Answer B

Question 39: When backing a commercial vehicle, what is the best practice?

Rely only on rear cameras
Ignore blind spots
Back quickly to finish fast
Use a helper and check mirrors (Correct answer)

Correct answer: Use a helper and check mirrors

Backing a large commercial vehicle presents significant blind spots and challenges, making it a high-risk maneuver. Using a helper (spotter) provides an extra set of eyes to guide the driver and identify obstacles, while constantly checking mirrors helps the driver monitor their surroundings. This combination maximizes visibility and significantly reduces the risk of accidents, prioritizing safety during complex maneuvers.

Question 40: During the walk-around inspection of a combination vehicle, what is a critical check for the fifth wheel assembly after coupling to a trailer?

Ensuring the fifth wheel is freshly painted.
Checking that there is a visible gap between the fifth wheel and the trailer apron.
Confirming the air lines have been painted red and blue.
Verifying that the locking jaws are fully closed around the kingpin and the release handle is in the locked position. (Correct answer)

Correct answer: Verifying that the locking jaws are fully closed around the kingpin and the release handle is in the locked position.

A secure connection is paramount. The driver must visually confirm that the locking jaws have properly engaged the trailer's kingpin. There should be no gap between the trailer apron and the fifth wheel skid plate, and the release handle must be in the correct position. A tug test should also be performed.

Question 41: Which part of the vehicle must you test during the brake system check?

Windshield wipers
The trailer hitch
Air, service, and parking brakes (Correct answer)
Only the hand brake

Correct answer: Air, service, and parking brakes

A comprehensive brake system check for a commercial vehicle must include all components: the air brake system (if applicable), the service brakes (foot pedal), and the parking brake. Testing each ensures that the vehicle can be safely stopped, slowed, and held stationary. This thorough inspection is critical for preventing brake failures and ensuring road safety for the driver and others.

Question 42: Why is checking lights and reflectors important?

They are only for decoration
They make the truck look cool
They help improve fuel economy
They ensure visibility and signaling (Correct answer)

Correct answer: They ensure visibility and signaling

Lights and reflectors are essential safety features that make a commercial vehicle visible to other drivers, especially during low light conditions, inclement weather, or at night. Properly functioning lights (headlights, tail lights, turn signals, brake lights) and clean reflectors ensure that the vehicle's presence and intended actions are clearly communicated to others on the road, preventing collisions and enhancing overall road safety.

Question 43: Which of the following best describes 'on-duty' time under federal HOS regulations?

All time from reporting for work until released from work responsibilities (Correct answer)
Only time spent actively driving the CMV
Time spent resting in the sleeper berth
Only time spent loading and unloading cargo

Correct answer: All time from reporting for work until released from work responsibilities

On-duty time includes all time from when a driver begins work or is required to be ready to work, covering driving, loading, inspections, and waiting.

Question 44: Sample question 1 for Transporting Cargo & Passengers Safely?

Answer D
Answer B (Correct answer)
Answer C
Answer A

Correct answer: Answer B

As this is a sample question without specific content, the correct answer 'Answer B' would represent the most appropriate or safest method for transporting cargo or passengers. It would align with established safety regulations and best practices specific to the safe handling and transport of goods or people in a commercial vehicle, ensuring compliance and minimizing risks.

Question 45: Sample question 3 for Safe Driving Practices & Hazard Awareness?

Answer C
Answer A
Answer B (Correct answer)
Answer D

Correct answer: Answer B

As this is a sample question without specific content, the correct answer 'Answer B' would represent the most appropriate or safest driving practice among the given options in a real scenario. It would align with established safety regulations and best practices for commercial vehicle operation and hazard awareness, ensuring driver and public safety.

Question 46: Which of the following statements about false log entries is correct?

Falsifying a log is a minor infraction with no serious consequences
Falsifying a log is a federal violation that can result in civil penalties and disqualification (Correct answer)
Logs only need to be accurate when crossing state lines
Dispatchers, not drivers, are solely responsible for log accuracy

Correct answer: Falsifying a log is a federal violation that can result in civil penalties and disqualification

Falsifying Hours of Service records is a serious federal violation under FMCSA rules, which can result in civil penalties up to $16,000 per violation and driver disqualification.

Question 47: Under the 70-hour/8-day rule, a driver may not drive after accumulating how many on-duty hours in 8 consecutive days?

70 hours (Correct answer)
80 hours
60 hours
65 hours

Correct answer: 70 hours

Drivers whose carrier operates vehicles every day of the week may use the 70-hour/8-day rule, capping on-duty time at 70 hours in 8 consecutive days.

Question 48: A driver is hauling a 40-foot-long, uniform piece of lumber on a flatbed trailer. What is the minimum number of tiedowns required for this load?

2 tiedowns
4 tiedowns (Correct answer)
5 tiedowns
3 tiedowns

Correct answer: 4 tiedowns

The general rule for cargo securement is to have at least one tiedown for every 10 feet of cargo. For a 40-foot load, this would be 4 tiedowns. Additionally, any cargo, no matter how small, requires a minimum of two tiedowns.

Question 49: Sample question 4 for Transporting Cargo & Passengers Safely?

Answer C
Answer D
Answer B (Correct answer)
Answer A

Correct answer: Answer B

Question 50: While transporting hazardous materials, you discover a slow leak from one of the containers. After stopping in a safe, isolated area, what is one of your immediate and primary responsibilities?

Notify local emergency responders and your carrier. (Correct answer)
Drive immediately to the nearest truck stop for help.
Attempt to patch the leak using available tools.
Wait for one hour to see if the leak stops on its own.

Correct answer: Notify local emergency responders and your carrier.

In any hazmat emergency, a driver's first priorities are safety and communication. After securing the scene, the driver must notify authorities (like 911) and their employer/carrier. This ensures a proper and timely response from trained personnel.

South Dakota Commercial Driver's License (CDL) Knowledge Tests

This certification allows individuals to operate commercial motor vehicles (CMVs) in South Dakota, requiring passing various knowledge and skills tests.

Questions

60 min

Time Limit

80%

To Pass

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