An empty cargo tank used for Class 3 flammable-liquid transportation breaks down. Which warning equipment is appropriate to carry?
Correct answer: Required reflective triangles, without flame-producing signals.
Flame-producing signals must not be carried on the specified cargo tank whether loaded or empty. The required reflective triangles provide a non-flame warning option.
Source: 49 CFR 393.95(f)(1), (g). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
When does the tire rule for covered hazardous-material vehicles require examination of each tire?
Correct answer: At the start of each trip and each time the vehicle is parked.
397.17(a) specifies trip-start and each-parking examinations. It does not replace the driver's other inspection duties.
Source: 49 CFR 397.17(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A covered hazmat truck has a flat tire. Where may it be driven under the repair-location exception?
Correct answer: To the nearest safe place for the necessary repair.
The tire must be repaired, replaced or properly inflated before driving, except travel to the nearest safe place to perform that work. Other safe-operation requirements still apply.
Source: 49 CFR 397.17(b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A tire on a covered hazmat vehicle is found overheated. What must be resolved before further operation?
Correct answer: The cause of the overheating must be corrected.
The driver must cause the overheated tire to be removed to a safe distance and correct the cause before operating again. Arrange qualified help and maintain applicable parking and attendance precautions.
Source: 49 CFR 397.17(c)–(d). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A Class 3 placard-required truck approaches an ordinary railroad grade crossing with no applicable exception. Where must it stop?
Correct answer: Between 15 and 50 feet from the tracks.
For a covered vehicle, stop within 50 feet but not closer than 15, then look and listen. Use a gear that allows crossing without shifting.
Source: 49 CFR 392.10(a), (a)(3)(vi). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A cargo tank formerly used to transport hazardous material is empty. At an ordinary grade crossing with no applicable exception, does empty status alone remove the federal stop requirement?
Correct answer: No; the rule includes loaded and empty hazardous-material cargo tanks.
392.10(a)(4) expressly covers such cargo tanks whether loaded or empty. The specific crossing exceptions in paragraph (b) must be considered separately.
Source: 49 CFR 392.10(a)(4), (b). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A transportation incident meets 171.15's NRC telephone-report criteria. When must the person in physical possession notify the NRC?
Correct answer: As soon as practical, no later than 12 hours after occurrence.
The telephone deadline is as soon as practical and within 12 hours. This is not permission to delay emergency assistance; the detailed written report has a separate deadline.
Source: 49 CFR 171.15(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A hazardous material directly causes the public to be evacuated for exactly one hour. Does this meet the evacuation trigger for NRC telephone reporting?
Correct answer: Yes; the trigger is one hour or more.
The current rule includes an evacuation lasting exactly one hour. The older handbook's more-than-one-hour wording should not be used to exclude this incident.
Source: 49 CFR 171.15(b)(1)(iii). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
A hazardous material directly causes an injury requiring admission to a hospital during transportation. Does that meet an NRC telephone-report trigger?
Correct answer: Yes; hospital admission is one of the listed triggers.
An injury requiring admittance to a hospital as a direct result of the hazardous material is a listed trigger. Mere cost estimates are not a substitute for checking the actual criteria.
Source: 49 CFR 171.15(b)(1)(ii). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
After an incident covered by 171.16, what is the ordinary deadline for the detailed hazardous-material incident report?
Correct answer: Within 30 days of discovering the incident.
The person in physical possession at the incident must submit the required DOT Form F 5800.1 within 30 days of discovery. This is separate from any prompt emergency call and NRC telephone notice.
Source: 49 CFR 171.16(a). Official eCFR XML dated September 10, 2026; reviewed September 14, 2026. ↗
