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CSA Scores Explained: FMCSA Safety Measurement System (SMS) Complete Guide

By CarrierLens Compliance Team • Last updated: 2025-04-01

Your CSA (Compliance, Safety, Accountability) score is one of the most important numbers in your business. It affects your insurance premiums, your eligibility for certain freight contracts, and whether FMCSA considers you a safety risk. Yet many carriers don't fully understand how the scores are calculated or what they can do to improve them.

What Is a CSA Score?

CSA scores are produced by FMCSA's Safety Measurement System (SMS), which analyzes data from roadside inspections, crashes, and investigation results to measure a motor carrier's safety performance. The SMS assigns carriers a percentile (0–100) within their peer group in each of seven BASIC categories. A higher percentile means worse performance relative to peers — the opposite of most scoring systems.

The Seven BASIC Categories

BASICWhat It MeasuresIntervention Threshold
Unsafe DrivingSpeeding, reckless driving, improper lane changes, seatbelt use65% (passenger: 60%)
Hours-of-Service (HOS) ComplianceELD violations, HOS log falsification, fatigued driving65% (passenger: 60%)
Driver FitnessInvalid CDL, expired medical card, lack of proper endorsements80%
Controlled Substances & AlcoholPositive drug/alcohol tests, open containers, driving under the influence80%
Vehicle MaintenanceBrake defects, tire violations, lighting defects, improper loads80% (passenger: 60%)
Hazardous Materials ComplianceHAZMAT packaging, labeling, placard violations80%
Crash IndicatorFrequency and severity of DOT-reportable crashes65%

How FMCSA Calculates Your CSA Score

SMS calculates each BASIC score using a point system that applies to violations found during roadside inspections and DOT-reportable crashes. Each violation is assigned a severity weight (1–10), then time-weighted so that more recent events count more heavily:

Your total weighted score is then compared against carriers with a similar number of inspections (your "peer group"). The percentile reflects where you rank within that group.

Important: FMCSA uses your score to prioritize which carriers to audit. Carriers with one or more BASIC scores above the intervention threshold are much more likely to receive a compliance review or focused investigation.

How CSA Scores Affect Your Business

How to Improve Your CSA Score

1. Review Every Inspection Report

Request copies of all DataQs inspection reports and challenge any errors within 60 days. Incorrect violations can be removed through the DataQs dispute process, which directly improves your score.

2. Address Your Worst BASIC First

Focus improvement efforts on the BASIC category with the highest percentile. Common root causes: Vehicle Maintenance issues from brake and lighting defects, and HOS issues from missed 30-minute breaks or ELD unassigned drive time.

3. Pre-Trip Inspections

Most Vehicle Maintenance violations are caught during roadside inspections on issues that should have been found during a driver's pre-trip inspection. Enforce thorough pre-trip inspection habits.

4. ELD Compliance Training

Unassigned drive time and incorrect duty status edits are the leading causes of HOS violations. Regular ELD log review catches problems before they become inspection violations.

5. Monitor Driver CSA Data

Individual driver violations accumulate in your BASIC scores. Monitor each driver's roadside inspection history through PSP reports and address repeat offenders before their data ages into your percentile.

CarrierLens tracks all seven BASIC scores in real time, sends alerts when any category approaches an intervention threshold, and provides driver-level breakdown so you know exactly which drivers and which violation types are driving your score up.

Frequently Asked Questions

What is a CSA score?
A CSA score refers to a motor carrier's percentile ranking in one or more of FMCSA's seven Behavior Analysis and Safety Improvement Categories (BASICs) under the Safety Measurement System (SMS). The BASICs are: Unsafe Driving, Hours of Service Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, Hazardous Materials Compliance, and Crash Indicator. Each BASIC compares your carrier's violation rate against carriers of similar size and time in operation, expressed as a percentile (0–100).
What CSA percentile is bad?
FMCSA flags carriers at the 'alert threshold' for each BASIC — typically the 65th percentile for most BASICs (meaning your violation rate is worse than 65% of similar carriers). Passenger carriers and HazMat carriers have lower thresholds (60th–75th depending on BASIC). The Controlled Substances BASIC has a 35th percentile alert threshold. Carriers above alert thresholds may receive warning letters, interventions, or be prioritized for compliance reviews.
How long do violations stay on a CSA score?
Violations remain in the SMS scoring window for 24 months from the date of the inspection, on a rolling basis. Violations in the first 6 months carry the highest time-weight multiplier (3x), violations in months 7–12 carry a 2x multiplier, and violations in months 13–24 carry a 1x multiplier. After 24 months, violations fall off the scoring window entirely — though they remain in FMCSA's inspection records.
How do I find my CSA score?
Your carrier's SMS BASIC percentiles are publicly available at safer.fmcsa.dot.gov. Enter your USDOT number and click on the SMS results. Carriers with fewer than 3 inspections in a BASIC category may not have a calculated percentile — FMCSA needs a minimum number of data points before publishing a percentile. Some BASIC data is suppressed from public view but still available to FMCSA enforcement staff.
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CarrierLens Feature

Monitor Your BASIC Percentiles in Real Time

CarrierLens RiskVision tracks your SMS BASIC percentiles and sends alerts when you cross the 65th or 75th percentile threshold — before you hit the FMCSA alert level that triggers a compliance review. See which roadside inspections are driving your scores and identify whether DataQs challenges are warranted.

Track Your CSA Scores →

Monitor BASIC Percentiles Before They Trigger a Compliance Review

CarrierLens RiskVision tracks your SMS BASIC percentiles in real time, alerts at early warning thresholds, and identifies which inspections are driving your scores — so you can address patterns before FMCSA schedules a compliance review.

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