Inspection Violations in SMS: Severity, Time and the Cap

Severity is relative within a BASIC

SMS methodology version 3.21 assigns each violation that pertains to a BASIC a weight reflecting its association with crash occurrence and consequences, on a scale where 1 is the lowest and 10 the highest crash risk relative to other violations in that BASIC. The methodology warns that weights are BASIC-specific: a 5 in one BASIC is not equivalent to a 5 in another, and weights from different BASICs should not be added or compared.

The full list of violations and weights is in FMCSA’s Appendix A spreadsheet. Which BASICs exist, and what a broker can infer from them, is covered in the guide to SMS and BASICs.

Sources: FMCSA: SMS methodology, version 3.21

Out-of-service violations and the cap

In several BASICs, a violation that resulted in a driver or vehicle out-of-service order receives an additional severity weight of 2. No out-of-service weight is assigned in the Unsafe Driving BASIC, where most violations are not out-of-service violations. The total severity weight for any one inspection in any one BASIC is capped at 30, applied before time weighting, and weights from other BASICs do not count toward that cap.

The cap means one badly failed inspection cannot dominate a carrier’s measure without limit. It also means counting violations on a report overstates the effect of a single inspection with many findings. The guide to driver, vehicle and carrier out-of-service findings explains what each kind of order means.

Sources: FMCSA: SMS methodology, version 3.21

Recent violations count more

Each violation also receives a time weight: 3 if recorded in the past six months, 2 if six to 12 months ago, and 1 if 12 to 24 months ago. Events older than 24 months are no longer used. The weighted value is the severity weight multiplied by the time weight, so the same violation counts three times as much this month as it will next year.

Adjudicated citations change the input. If a citation tied to a violation is dismissed or found not guilty, the violation is removed; if the driver is convicted of a different charge, its severity is set to 1 with no out-of-service weight. The carrier or driver must submit certified court documentation through a DataQs request, and the policy applies to inspections on or after August 23, 2014. The guide to disputing a carrier safety record covers that process.

Sources: FMCSA: SMS methodology, version 3.21

Why you cannot rebuild the percentile

A BASIC measure divides the weighted violations by an exposure figure, such as average power units multiplied by a utilization factor based on reported mileage, or relevant inspections for other BASICs, and the percentile then compares the carrier with a peer group. Under the FAST Act, FMCSA no longer publicly displays property carriers’ complete SMS results; carriers must log in to see them.

Inspection counts and out-of-service rates need their own denominators, explained in the guide to carrier inspection rates. How stale mileage changes the exposure figure is covered in the guide to the MCS-150 date and mileage.

FMCSA announced changes to SMS in November 2024, including simplified severity weights. The methodology document FMCSA revised in June 2026 still describes version 3.21, which is what this guide summarizes.

Sources: FMCSA: SMS methodology, version 3.21; FMCSA: Enhanced Carrier Safety Measurement System, notice (89 FR 91874, November 20, 2024)

Reading a violation list

An illustrative note: “Three vehicle-maintenance violations in two inspections in the past six months, one out-of-service; no repeats of the same violation; no driver violations. Asked carrier about corrective maintenance; answer recorded.”

A recommended way to read a carrier’s inspection history without inventing a score:

• Group violations by BASIC and do not compare weights across groups.
• Note which violations led to an out-of-service order and when each inspection happened.
• Look for the same violation recurring across inspections rather than a long list from one stop.
• Ask whether any citation was dismissed or reduced, and whether a DataQs request is pending.

Sources: FMCSA: SMS methodology, version 3.21