DOT North American Standard (NAS) Inspection Levels I–VI — Questions and Answers
Question 1: A DOT inspector stops a commercial motor vehicle and conducts a full examination of both the driver's documents and the vehicle's mechanical components, including a complete underbody inspection. Which NAS inspection level has been performed?
- Level I – North American Standard Inspection (Correct answer)
- Level II – Walk-Around Driver/Vehicle Inspection
- Level III – Driver/Credential/Administrative Inspection
- Level V – Vehicle-Only Inspection
Correct answer: Level I – North American Standard Inspection
Level I is the most comprehensive roadside inspection, covering both the driver (credentials, hours of service, medical certificate) and a full mechanical inspection of the vehicle including an underbody examination. It is the standard against which all other levels are measured.
Question 2: An inspector at a fixed facility inspects a vehicle that has no driver present — the driver has departed. Which NAS inspection level is most appropriate?
- Level II – Walk-Around Driver/Vehicle Inspection
- Level III – Driver/Credential/Administrative Inspection
- Level IV – Special Inspections
- Level V – Vehicle-Only Inspection (Correct answer)
Correct answer: Level V – Vehicle-Only Inspection
Level V is the vehicle-only inspection, conducted when no driver is present. It covers the same vehicle components as a Level I inspection but omits the driver examination because the driver is unavailable.
Question 3: During a Level III inspection, an inspector reviews the driver's commercial driver's license, medical examiner's certificate, and hours-of-service records. The inspector does NOT examine which of the following?
- Skill performance evaluation certificates
- Brake adjustment on all axles (Correct answer)
- Driver's daily log or ELD records
- Hazardous materials shipping papers held by the driver
Correct answer: Brake adjustment on all axles
Level III is a driver/credential/administrative inspection only. It does not include any physical examination of the vehicle's mechanical components, such as brake adjustment. Brake checks are part of Level I and Level II inspections.
Question 4: Which NAS inspection level is specifically designed for targeted enforcement of a single regulatory area, such as verifying that cargo securement devices are properly applied across an entire fleet at a terminal?
- Level I – North American Standard Inspection
- Level II – Walk-Around Driver/Vehicle Inspection
- Level IV – Special Inspections (Correct answer)
- Level VI – Radioactive Material Inspection
Correct answer: Level IV – Special Inspections
Level IV covers special inspections, which are directed at a single element of compliance — such as a focused cargo securement audit, a lights-only check, or a targeted enforcement campaign. These inspections are not random; they are pre-planned to address a specific regulatory element.
Question 5: A Level II walk-around inspection differs from a Level I inspection primarily because the inspector:
- Does not examine driver qualifications or HOS records
- Examines only the exterior of the vehicle without going under it (Correct answer)
- Only applies to vehicles carrying hazardous materials
- Is conducted solely by a state-certified inspector, not a federal agent
Correct answer: Examines only the exterior of the vehicle without going under it
The defining difference of a Level II inspection is that the inspector does not go beneath the vehicle. All accessible components are examined from the outside (walk-around), but items requiring an underbody examination are excluded. Driver documents are still reviewed in Level II.
Question 6: Under CVSA protocol, which inspection level is reserved exclusively for vehicles transporting highway route controlled quantities (HRCQ) of radioactive materials?
- Level I – North American Standard Inspection
- Level IV – Special Inspections
- Level V – Vehicle-Only Inspection
- Level VI – Enhanced NAS Inspection for Radioactive Shipments (Correct answer)
Correct answer: Level VI – Enhanced NAS Inspection for Radioactive Shipments
Level VI is the Enhanced NAS Inspection for Radioactive Shipments. It includes all Level I inspection elements plus enhanced procedures specific to vehicles hauling HRCQ radioactive material, such as radiation dose rate measurements and radiological placarding verification.
DOT North American Standard (NAS) Inspection Levels I–VI
A DOT inspector stops a commercial motor vehicle and conducts a full examination of both the driver's documents and the vehicle's mechanical components, including a complete underbody inspection.
Which NAS inspection level has been performed?