CDL Hazmat highway carriage, loading and segregation practice questions
20 free practice questions from 49 CFR Part 177. Each answer is explained and linked to the rule it comes from.
CDL Hazmat highway carriage, loading and segregation
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Scope, responsibility and training
1. Under 177.800(b), unless the Hazardous Materials Regulations specifically give a particular duty to another person, who must perform the duties specified in Part 177?
- A. The offeror who signed the shipper's certification
- B. The consignee named on the shipping paper
- C. Each carrier, including a connecting carrier
- D. The State that issued the driver's commercial driver's license
Show answer
Answer: C. Each carrier, including a connecting carrier
Unless the subchapter "specifically provides that another person shall perform a particular duty, each carrier, including a connecting carrier, shall perform the duties specified and comply with all applicable requirements in this part".
2. Under 177.816(b), who must receive the specialized cargo tank and portable tank training, on top of the general driver training?
- A. Each person who operates a cargo tank, or a vehicle with a portable tank with a capacity of 1,000 gallons or more
- B. Only a person who operates a vehicle placarded for Class 1 (explosive) materials
- C. Only a person who operates a vehicle with a portable tank of less than 1,000 gallons
- D. Only a person who loads cargo tanks but never drives them
Show answer
Answer: A. Each person who operates a cargo tank, or a vehicle with a portable tank with a capacity of 1,000 gallons or more
177.816(b) says "each person who operates a cargo tank or a vehicle with a portable tank with a capacity of 1,000 gallons or more must receive training applicable to the requirements of this subchapter".
Source: eCFR: 49 CFR 177.816, Driver training (as of Nov 4, 2026)
Shipping papers in the vehicle
3. A motor carrier delivers a placarded transport vehicle to a rail carrier for further transportation. What does 177.817(c) require the motor carrier to mark on the shipping paper?
- A. The driver's CDL number and endorsements
- B. The time the vehicle was handed over to the rail carrier
- C. The name of the railroad and the rail car's number
- D. A description of the transport vehicle and the kind of placard affixed to it
Show answer
Answer: D. A description of the transport vehicle and the kind of placard affixed to it
When it "offers or delivers a freight container or transport vehicle to a rail carrier for further transportation", a motor carrier shall mark on the shipping paper "(1) A description of the freight container or transport vehicle; and (2) The kind of placard affixed to the freight container or transport vehicle."
Source: eCFR: 49 CFR 177.817, Shipping papers (as of Nov 4, 2026)
4. A carrier keeps a copy of each hazardous materials shipping paper it receives, as 177.817(f) requires. Which detail must each retained copy include?
- A. The consignee's signature at delivery
- B. The date of acceptance by the carrier
- C. The license plate number of the vehicle used
- D. The name of every driver who handled the load
Show answer
Answer: B. The date of acceptance by the carrier
Under 177.817(f), "Each shipping paper copy must include the date of acceptance by the carrier."
Source: eCFR: 49 CFR 177.817, Shipping papers (as of Nov 4, 2026)
5. 177.817(e) tells the driver and the carrier how to distinguish and store the shipping paper in the vehicle. What does it say those steps must ensure?
- A. That the shipping paper is readily available to, and recognizable by, authorities in the event of accident or inspection
- B. That the consignee can sign the shipping paper on arrival
- C. That the shipping paper is kept out of view of passengers
- D. That the shipping paper stays sealed until the vehicle reaches the consignee
Show answer
Answer: A. That the shipping paper is readily available to, and recognizable by, authorities in the event of accident or inspection
The driver and each carrier "shall ensure that the shipping paper required by this section is readily available to, and recognizable by, authorities in the event of accident or inspection."
Source: eCFR: 49 CFR 177.817, Shipping papers (as of Nov 4, 2026)
General loading and unloading
6. 177.834(h) bars any discharge of the contents of a container between the point of origin and the point of billed destination. What does that paragraph say it shall not be construed to prohibit?
- A. Opening a container in transit to check what is inside it
- B. Transferring the contents to another container at a stop chosen by the driver
- C. The fueling of machinery or vehicles used in road construction or maintenance
- D. Replacing part of a container's contents with a different material during the trip
Show answer
Answer: C. The fueling of machinery or vehicles used in road construction or maintenance
"There must be no tampering with such container or the contents thereof nor any discharge of the contents of any container between point of origin and point of billed destination." However, "Nothing contained in this paragraph shall be so construed as to prohibit the fueling of machinery or vehicles used in road construction or maintenance."
Source: eCFR: 49 CFR 177.834, General requirements (as of Nov 4, 2026)
7. 177.834(j)(2) requires all valves and other closures in liquid discharge systems of a cargo tank motor vehicle containing a hazardous material to be closed and free of leaks before it is driven. Which exception does that paragraph allow?
- A. Valves on a cargo tank carrying less than a placarded quantity
- B. External emergency self-closing valves on MC 338 cargo tanks containing the residue of cryogenic liquids may remain either open or closed during transit
- C. Valves on any cargo tank driven less than 25 miles
- D. Valves on a cargo tank carrying Class 8 (corrosive) materials
Show answer
Answer: B. External emergency self-closing valves on MC 338 cargo tanks containing the residue of cryogenic liquids may remain either open or closed during transit
The rule applies to a cargo tank motor vehicle "containing a hazardous material regardless of quantity", "except external emergency self-closing valves on MC 338 cargo tanks containing the residue of cryogenic liquids may remain either open or closed during transit."
Source: eCFR: 49 CFR 177.834, General requirements (as of Nov 4, 2026)
Cargo tank attendance
8. A facility meets the cargo tank attendance requirement with video cameras and monitors at a remote control station. Under 177.834(i)(3)(ii), what must happen if video monitoring capability is lost?
- A. Loading or unloading operations must be immediately terminated
- B. Loading may continue until the cargo tank is full
- C. A qualified person must inspect the operation within 60 minutes
- D. The motor carrier must be notified before the next load
Show answer
Answer: A. Loading or unloading operations must be immediately terminated
"Upon loss of video monitoring capability or instrumentation and signaling systems, loading or unloading operations must be immediately terminated", and a qualified person "must immediately resume attending" the cargo tank in person.
Source: eCFR: 49 CFR 177.834, General requirements (as of Nov 4, 2026)
9. Under 177.834(i)(2), a motor carrier must ensure a cargo tank is attended by a qualified person during unloading. When does that obligation cease?
- A. As soon as the cargo tank enters the consignee's gate
- B. After the driver hands the shipping paper to the consignee
- C. After the first 60 minutes of unloading
- D. When the carrier's transportation obligation is fulfilled, the cargo tank has been placed on the consignee's premises, and the motive power has been removed from the cargo tank and from the premises
Show answer
Answer: D. When the carrier's transportation obligation is fulfilled, the cargo tank has been placed on the consignee's premises, and the motive power has been removed from the cargo tank and from the premises
The obligation "ceases when: (i) The carrier's obligation for transporting the materials is fulfilled; (ii) The cargo tank has been placed upon the consignee's premises; and (iii) The motive power has been removed from the cargo tank and removed from the premises." All three conditions must be met.
Source: eCFR: 49 CFR 177.834, General requirements (as of Nov 4, 2026)
10. Under 177.834(i)(4), a person attending cargo tank loading in person (not by remote monitoring and not by inspecting special hoses) must have been made aware of the nature of the material and instructed on emergency procedures. What else makes that person "qualified"?
- A. Holding a hazardous materials endorsement
- B. Being authorized to move the cargo tank and having the means to do so
- C. Being employed by the consignee
- D. Having at least one year of tank vehicle experience
Show answer
Answer: B. Being authorized to move the cargo tank and having the means to do so
Apart from remote observers and persons inspecting hoses under (i)(3)(iii), a qualified person also "is authorized to move the cargo tank, and has the means to do so."
Source: eCFR: 49 CFR 177.834, General requirements (as of Nov 4, 2026)
11. A cargo tank is unloading a material that meets the combustible liquid definition in 173.150(f). Where does 177.837(d) require the attending qualified person to remain?
- A. Within 300 feet of the cargo tank only
- B. Within 300 feet of the cargo tank and 100 feet of the delivery hose
- C. Within 150 feet of the cargo tank and 25 feet of the delivery hose
- D. Within 50 feet of the receiving container only
Show answer
Answer: C. Within 150 feet of the cargo tank and 25 feet of the delivery hose
The qualified person "must remain within 45.72 meters (150 feet) of the cargo tank and 7.62 meters (25 feet) of the delivery hose" and must look at both the cargo tank and the receiving container at least once every five minutes when unloading takes more than five minutes.
Source: eCFR: 49 CFR 177.837, Class 3 (flammable liquid) materials (as of Nov 4, 2026)
Loading rules by hazard class
12. Class 1 (explosive) materials generally may not be loaded or unloaded with the engine running. Under 177.835(a), which vehicle's engine may be used during loading or unloading?
- A. Any vehicle, when the outside temperature is at or below 10 °F
- B. Any vehicle whose driver stays in the cab
- C. Any vehicle carrying only Division 1.4 materials
- D. A multipurpose bulk truck, to operate the vehicle's pumping equipment
Show answer
Answer: D. A multipurpose bulk truck, to operate the vehicle's pumping equipment
177.835(a) makes an exception: "the engine of a multipurpose bulk truck (see paragraph (d) of this section) and the engine of a cargo tank motor vehicle transporting a single bulk hazardous material for blasting may be used for the operation of the pumping equipment of the vehicle during loading or unloading." The 10 °F diesel rule in 177.837(a) is for Class 3 cargo tanks only.
Source: eCFR: 49 CFR 177.835, Class 1 (explosive) materials (as of Nov 4, 2026)
13. 177.838(a) requires Class 4 and Class 5 lading to be contained within the vehicle body and covered, with the tailgate closed. Which vehicles does that paragraph say it need not apply to?
- A. Pick-up and delivery vehicles used in no other transportation than in and about cities, towns, or villages
- B. Flatbed vehicles in interstate transportation
- C. Vehicles operated by a private carrier
- D. Vehicles that travel only at night
Show answer
Answer: A. Pick-up and delivery vehicles used in no other transportation than in and about cities, towns, or villages
"Provided, however, That the provisions of this paragraph need not apply to “pick-up and delivery” motor vehicles when such motor vehicles are used in no other transportation than in and about cities, towns, or villages."
14. Under 177.841(c), what makes the transportation of a Division 2.3 (poisonous gas) or Division 6.1 (poisonous) material not permitted?
- A. A trip that crosses a State line
- B. Transportation during the hours of darkness
- C. Any interconnection between packagings
- D. A load of fewer than four packages
Show answer
Answer: C. Any interconnection between packagings
"The transportation of a Division 2.3 (poisonous gas) or Division 6.1 (poisonous) material is not permitted if there is any interconnection between packagings."
15. A package bears a POISON label displaying the text "PG III". Under 177.841(e)(3), when may a motor carrier transport it with material known to be foodstuffs?
- A. When the package rides in the driver's compartment, away from the foodstuffs
- B. When the package is separated so that, in the event of leakage under conditions normally incident to transportation, commingling with the foodstuffs would not occur
- C. When the foodstuffs are covered with a tarpaulin
- D. When the driver holds a hazardous materials endorsement
Show answer
Answer: B. When the package is separated so that, in the event of leakage under conditions normally incident to transportation, commingling with the foodstuffs would not occur
Such a package may go with foodstuffs only if the Packing Group III material "is separated in a manner that, in the event of leakage from packages under conditions normally incident to transportation, commingling of hazardous materials with foodstuffs, feed or any other edible material would not occur." A POISON-labeled package may never ride "in the driver's compartment (including a sleeper berth)".
Segregation
16. Apart from the segregation table, which pairing does 177.848(c) bar from being stored, loaded and transported together?
- A. Division 4.2 materials with Class 8 liquids
- B. Class 9 materials with Class 3 materials
- C. Combustible liquids with Class 8 liquids
- D. Division 2.2 materials with Class 9 materials
Show answer
Answer: A. Division 4.2 materials with Class 8 liquids
In addition to the table, "Division 4.2 materials may not be stored, loaded and transported with Class 8 liquids".
Source: eCFR: 49 CFR 177.848, Segregation of hazardous materials (as of Nov 4, 2026)
17. Some rows of the 177.848(d) table carry note "A" in the second column. Under 177.848(e)(5), what does note A allow, notwithstanding the "X"?
- A. Any Division 5.1 (oxidizing) material may be loaded with Division 1.1 materials
- B. Ammonium nitrate may be loaded with Division 1.3 materials
- C. Ammonium nitrate may be loaded with Division 1.1 materials even where 177.835(c) prohibits it
- D. Ammonium nitrate (UN1942) and ammonium nitrate fertilizer may be loaded or stored with Division 1.1 or Division 1.5 materials, unless 177.835(c) prohibits it
Show answer
Answer: D. Ammonium nitrate (UN1942) and ammonium nitrate fertilizer may be loaded or stored with Division 1.1 or Division 1.5 materials, unless 177.835(c) prohibits it
Note A means "ammonium nitrate (UN1942) and ammonium nitrate fertilizer may be loaded or stored with Division 1.1 (explosive) or Division 1.5 materials, unless otherwise prohibited by § 177.835(c)." It covers only those two materials and only Divisions 1.1 and 1.5.
Source: eCFR: 49 CFR 177.848, Segregation of hazardous materials (as of Nov 4, 2026)
18. The 177.848(d) table shows an "O" between Class 8 (corrosive) liquids and Division 5.1 (oxidizers). Besides separating them so leaking packages could not commingle, what else does 177.848(e)(3) say?
- A. Class 8 liquids must be loaded above the Division 5.1 materials
- B. Class 8 liquids may not be loaded above or adjacent to Class 4 or Class 5 materials, except that shippers may load truckload shipments together when it is known the mixture would not cause a fire or a dangerous evolution of heat or gas
- C. Class 8 liquids may be loaded next to Class 5 materials if the packages are shrink-wrapped
- D. The Division 5.1 materials must be carried in a separate cargo tank
Show answer
Answer: B. Class 8 liquids may not be loaded above or adjacent to Class 4 or Class 5 materials, except that shippers may load truckload shipments together when it is known the mixture would not cause a fire or a dangerous evolution of heat or gas
"Notwithstanding the methods of separation employed, Class 8 (corrosive) liquids may not be loaded above or adjacent to Class 4 (flammable) or Class 5 (oxidizing) materials; except that shippers may load truckload shipments of such materials together when it is known that the mixture of contents would not cause a fire or a dangerous evolution of heat or gas."
Source: eCFR: 49 CFR 177.848, Segregation of hazardous materials (as of Nov 4, 2026)
Emergencies, disabled vehicles and repairs
19. 177.823(a) bars a carrier from moving a transport vehicle containing a hazardous material unless it is marked and placarded (or as authorized in 171.12a). In an emergency, which of these lets the carrier move it anyway?
- A. The consignee asks for the delivery
- B. The trip is shorter than 5 miles
- C. The driver holds a hazardous materials endorsement
- D. Moving the vehicle is necessary to protect life or property
Show answer
Answer: D. Moving the vehicle is necessary to protect life or property
In an emergency, one of three options applies: "(1) The vehicle is escorted by a representative of a state or local government; (2) The carrier has permission from the Department; or (3) Movement of the transport vehicle is necessary to protect life or property."
Source: eCFR: 49 CFR 177.823, Movement of motor vehicles in emergency situations (as of Nov 4, 2026)
20. An empty cargo tank used for Class 3 (flammable liquid) materials is stopped on a highway shoulder for a cause other than a necessary traffic stop. Under 177.854(f), warning devices must be set out in the manner prescribed by which section?
- A. § 392.22
- B. None, because the tank is empty
- C. § 392.25
- D. § 397.5
Show answer
Answer: C. § 392.25
"For cargo tanks used for the transportation of Class 3 (flammable liquid) or Division 2.1 (flammable gas) materials, whether loaded or empty, and vehicles transporting Division 1.1, 1.2, or 1.3 (explosive) materials, warning devices must be set out in the manner prescribed by § 392.25 of this title."
Source: eCFR: 49 CFR 177.854, Disabled vehicles and broken or leaking packages; repairs (as of Nov 4, 2026)