FMCSA Roadside Inspection Guide: Levels, OOS Criteria, and How Violations Affect Your CSA Scores

By CarrierLens Compliance Team • Last updated: 2026-05-01

Roadside inspections are the primary mechanism through which FMCSA measures motor carrier safety compliance. Every inspection result is uploaded to the Motor Carrier Management Information System (MCMIS) and becomes part of your carrier's compliance record — feeding directly into your CSA BASIC percentile scores. Understanding the six inspection levels, what inspectors look for, and how violations affect your scores is essential knowledge for every fleet manager.

The Six Levels of DOT Roadside Inspection

All roadside inspections follow North American Standard (NAS) procedures developed by CVSA (Commercial Vehicle Safety Alliance). There are six inspection levels:

• Level I — Full North American Standard Inspection: The most comprehensive inspection. Includes a complete review of the driver's credentials (CDL, medical certificate, HOS logs/ELD), a vehicle walk-around, and an under-vehicle inspection. This is the most common inspection type and the one that produces the most violations.
• Level II — Walk-Around Driver and Vehicle Inspection: Same as Level I except the inspector does not go under the vehicle. Covers all driver documents and an exterior vehicle inspection including tires, brakes (visually accessible), lights, and cargo securement.
• Level III — Driver-Only Inspection: Focuses exclusively on the driver — credentials, HOS records, ELD compliance, seat belt, driver fitness. No vehicle inspection.
• Level IV — Special Study Inspection: A one-time or limited inspection focusing on a specific safety element for data collection purposes. Results are typically not used in SMS scoring.
• Level V — Vehicle-Only Inspection: A full vehicle inspection without the driver present (for example, at a carrier facility). Covers mechanical components, cargo securement, hazmat placarding.
• Level VI — Radioactive Materials Inspection: Enhanced Level I inspection for vehicles transporting select radioactive materials. Includes radiation survey equipment.

Out-of-Service Criteria

Inspectors follow CVSA Out-of-Service (OOS) criteria to determine when a driver or vehicle must be taken out of service immediately. Common OOS conditions include:

• Driver OOS: HOS violation (hours exceeded), invalid or expired CDL, no medical certificate, prohibited Clearinghouse status, apparent impairment
• Vehicle OOS: Brake adjustment out of limit, brake lining/pad defects, tire failures (flat, exposed cords, inadequate tread depth), steering defects, frame cracks, lighting defects on required lights
• Cargo OOS: Cargo securement violations where load is at risk of shifting or falling

A driver OOS violation prohibits the driver from operating until the condition is corrected. A vehicle OOS violation prohibits operation of that vehicle until repaired, regardless of whether the driver is otherwise compliant.

How Violations Are Weighted in the SMS

Not all violations affect your CSA scores equally. Each violation in the FMCSA Safety Measurement System is assigned a severity weight from 1 (least severe) to 10 (most severe). Higher-severity violations have a greater impact on your BASIC percentile. Examples:

• Speeding 15+ mph over limit: severity 10 (Unsafe Driving BASIC)
• Texting while driving: severity 10 (Unsafe Driving BASIC)
• Brake adjustment violation (critical): severity 8 (Vehicle Maintenance BASIC)
• HOS log violation — falsification: severity 7 (HOS Compliance BASIC)
• Tire tread depth below minimum: severity 6 (Vehicle Maintenance BASIC)
• No valid annual inspection: severity 5 (Vehicle Maintenance BASIC)
• Lighting violation: severity 3 (Vehicle Maintenance BASIC)

Violations are also weighted by recency — violations from the past 6 months carry a 3x time weight, 7–12 months carry 2x, and 13–24 months carry 1x before dropping off entirely.

Which Inspections Count in SMS Scoring?

Only inspections with at least one recordable violation — or an OOS order — count toward your SMS BASIC percentile calculations. "Clean" inspections (no violations) do not improve your percentile directly, but they increase your inspection count, which can dilute the statistical weight of violations if your violation rate is low.

Challenging Inspection Errors Through DataQs

If an inspection report contains inaccurate information — a violation that was not observed, a violation incorrectly attributed to your vehicle, an error in the carrier identification — you can file a DataQs challenge through FMCSA's website. Successful DataQs challenges that result in a violation being corrected or removed can meaningfully improve your BASIC percentile.

DataQs challenges are most effective when:

• The violation was not observed during the inspection (inspector error)
• The violation was attributed to the wrong carrier (incorrect DOT number assigned)
• The vehicle shown on the report was not your vehicle
• The inspection occurred on a date your vehicle or driver was not in that location

CarrierLens RiskVision flags DataQs challenge candidates automatically by comparing inspection records against your fleet's location and driver assignment data.