A CSA score is your carrier's percentile ranking within FMCSA's Safety Measurement System (SMS) across 7 Behavior Analysis and Safety Improvement Categories (BASICs). Scores are calculated from roadside inspection violations using published severity weights (1–10) multiplied by time-decay weights (0.5–3×), then normalized against peer carriers. Carriers above the intervention threshold — 65th percentile for Unsafe Driving, HOS, and Crash Indicator; 80th for Driver Fitness, Controlled Substances, Vehicle Maintenance, and Hazmat — face increased audit targeting, inspection selection, and insurance surcharges of 15–40% per renewal cycle.
What Is a CSA Score? The Full Picture
CSA — Compliance, Safety, Accountability — is FMCSA's data-driven enforcement prioritization system, operational since December 2010 and continuously updated with monthly inspection data. It replaced the previous SafeStat system and introduced percentile-based scoring that compares carriers against peers with similar inspection exposure.
The CSA system does two things: it measures carrier safety performance across the 7 BASICs, and it uses those measurements to prioritize which carriers receive more scrutiny — more inspections, more audits, more focused investigations. The scores are publicly visible to every shipper, broker, and insurer who wants to check them.
What CSA scores are not: They are not a safety rating. FMCSA's official safety ratings are Satisfactory, Conditional, and Unsatisfactory — issued after compliance reviews. CSA scores are a risk signal used to prioritize enforcement resources. But in practice, high CSA scores in any BASIC increase the probability of being selected for the compliance review that produces an official safety rating.
How FMCSA Calculates CSA Scores: The SMS Methodology
FMCSA's Safety Measurement System calculates BASIC scores through a three-step process. Understanding the formula is essential because it tells you exactly which violations hurt most and how quickly a score recovers over time.
Every violation in the SMS has a published severity weight from 1 (minor) to 10 (most severe). Out-of-service-level violations — brakes, tires, expired CDL, positive drug test — score 10. Non-OOS violations like inoperative lamps score lower. The severity weight is fixed per violation type; it does not vary by carrier or fleet size.
Each violation is multiplied by a time weight based on when it occurred relative to today. Most recent 6 months: ×3. 7–12 months ago: ×2. 13–24 months ago: ×1. 25–36 months ago: ×0.5. Violations drop off entirely after 36 months. This is why a single bad inspection month can spike a score dramatically — all violations carry maximum time weight simultaneously.
The raw score (sum of Severity × Time) is normalized against peer carriers with similar inspection exposure. The result is a percentile — not a raw number. This is why small carriers are more exposed: a 5-truck carrier with 2 violations has higher proportional exposure than a 50-truck carrier with the same absolute number of violations.
CSA Score Estimator
Add your roadside inspection violations below. Scores are estimated using FMCSA SMS severity weights and time-decay methodology. Results are directional estimates — actual percentiles depend on peer comparison data updated monthly by FMCSA.
FMCSA Violation Severity Weights — Complete Reference Table
The following severity weights are published in FMCSA's SMS methodology documentation. Every carrier can look up the exact weight for any violation. These are the numbers FMCSA actually uses — not estimates.
Source: FMCSA Safety Measurement System (SMS) Methodology document, current as of April 2026. Complete violation severity weight table available at ai.fmcsa.dot.gov/SMS.
FMCSA CSA Intervention Thresholds by BASIC
FMCSA sets different intervention thresholds for each BASIC based on the statistical relationship between violation patterns and crash risk. Thresholds are higher (more permissive) for BASICs where the crash-correlation research showed lower predictive strength.
CSA Score Insurance Impact in 2026: What Underwriters Actually Pull
In 2026, virtually every standard commercial trucking insurer pulls FMCSA SMS data as part of their underwriting workflow. This is not a policy — it is standard practice. The data is free, publicly accessible, and takes 30 seconds to retrieve. Underwriters use it to assess loss probability before quoting or renewing a policy.
Standard market rates available. Multiple insurers will quote. No surcharge.
15–25% premium surcharge at renewal. Some markets non-renew. Surplus lines market opens.
Standard market unavailable. Surplus lines only, often 30–40% surcharge. Some non-renew entirely.
The Controlled Substances/Alcohol BASIC is the most severe insurance trigger. A score above the 80th percentile in this BASIC — or a single positive drug test in your inspection history — will follow your operating authority for 36 months. Most standard market insurers will not write a policy for a carrier with an active CS/A score above threshold regardless of other BASIC performance.
Why Small Carriers Cross CSA Thresholds Faster
Carriers with fewer than 20 power units have a statistically higher out-of-service rate during roadside inspections than fleets of 100 or more trucks. The CSA scoring math compounds this disadvantage.
Note: Percentile estimates above use the CSA Score Estimator methodology (Severity × Time ÷ normalized exposure). Actual SMS percentiles update monthly and depend on peer comparison data.
How to Improve Your CSA Score: What Actually Works
There is no shortcut to improving a CSA score. The only legitimate paths are: preventing new violations, challenging inaccurate data, and waiting for old violations to time-decay. Here is what actually moves the needle, ordered by impact.
Severity weight 10 violations are avoidable at pre-trip inspection. Brakes, tires, steering, lamps. A pre-trip DVIR that catches and repairs these items costs zero points. The same defect caught at a weigh station costs 10 × 3 = 30 raw score points.
Expired CDL (SW=10) and expired medical certificate (SW=7) are fully preventable with basic expiration tracking. Both are Driver Fitness violations — BASIC threshold 80th percentile. A single expired CDL on a small fleet often pushes the carrier above threshold immediately.
Operating a driver who is in prohibited Clearinghouse status is a severity-10 violation. Clearinghouse query at hire and annual query are both required. The annual query cost is $1.25 per driver. The alternative is a SW=10 violation in your most insurance-sensitive BASIC.
HOS violations — especially false logs (SW=10) and driving beyond limits (SW=7) — are among the most common triggers for elevated HOS Compliance BASIC scores. ELD data is visible to roadside inspectors in real time. HOS violations that might have gone undetected with paper logs are now surfaced on every Level I inspection.
Check your carrier's scores at ai.fmcsa.dot.gov/SMS. Review the violation data in your SMS record against your inspection reports (Form MCSA-5875). Data entry errors — wrong vehicle, wrong driver, wrong violation code — are common and correctable through DataQs. Inaccurate data that sits unchallenged for 36 months costs you real percentile points.
DataQs: How to Dispute Inaccurate CSA Violations
FMCSA's DataQs system (dataqs.fmcsa.dot.gov) is the formal mechanism for challenging inspection data that you believe is inaccurate. DataQs challenges do not remove accurate violations — they correct errors in the underlying data.
- ✓Violation dismissed in court — submit court dismissal
- ✓Wrong vehicle or driver on inspection report
- ✓Violation code recorded incorrectly by officer
- ✓Equipment repaired before inspection began
- ✓Inspection report with factual errors (time, location, unit number)
- ✗Accurate violations you disagree with
- ✗Violations where no citation was issued but defect was observed
- ✗Post-inspection repairs (can't retroactively clear OOS)
- ✗Violations that were upheld in court
- ✗Violations outside the 36-month window (already expired)
Track the violations that drive CSA scores — automatically
TruckComplianceHQ tracks CDL expirations, medical certificates, annual inspections, and Clearinghouse query requirements — the items that generate severity-7 and severity-10 violations before a truck ever gets pulled over. Free for the first 5 drivers.
Run Free Compliance Check →Full dashboard trial →Severity weights and thresholds sourced from the FMCSA SMS Methodology documentation and 49 CFR regulatory text (Parts 382, 383, 391, 392, 393, 395, 396). Percentile estimates in this tool are directional — actual FMCSA percentile scores update monthly and depend on peer comparison data not publicly available in full. Always verify your actual BASIC scores directly at ai.fmcsa.dot.gov/SMS. This tool is for educational and risk-assessment purposes only — not legal advice.
Frequently Asked Questions
Regulatory References & Data Sources
All violation severity weights, BASIC thresholds, and regulatory citations in this tool are drawn from official FMCSA sources. Verify current requirements directly through official sources.
- FMCSA Safety Measurement System (SMS) — Carrier Scores & Methodology
- FMCSA SMS Methodology — Violation Severity Weights (published)
- FMCSA DataQs — Dispute Inaccurate Inspection Data
- 49 CFR Part 382 — Controlled Substances and Alcohol Testing
- 49 CFR Part 391 — Driver Qualification Standards
- 49 CFR Part 395 — Hours of Service
- 49 CFR Part 396 — Inspection, Repair, and Maintenance
- FMCSA Drug & Alcohol Clearinghouse
- CVSA North American Standard Out-of-Service Criteria