CSA — Compliance, Safety, Accountability — is the FMCSA's enforcement program, and the Safety Measurement System (SMS) is the dashboard inside it. Every motor carrier with at least one roadside inspection in the past 24 months has SMS data. Most carriers either don't look at it or don't know what they're looking at.
Here's the short version.
The 7 BASICs
Each BASIC (Behavior Analysis and Safety Improvement Category) tracks a different slice of safety:
- Unsafe Driving — speeding, reckless driving, mobile phone use, improper lane changes
- HOS Compliance — drive-time overages, logbook falsification, ELD malfunction mishandling
- Driver Fitness — DQ file gaps, expired CDLs, expired MECs
- Controlled Substances & Alcohol — failed tests, refusals, prior violations not handled
- Vehicle Maintenance — brakes, tires, lights, OOS conditions found roadside
- HazMat Compliance — placards, paperwork, leaks (HazMat carriers only)
- Crash Indicator — DOT-reportable crashes, preventable and non-preventable
How the score works
For each BASIC, your inspection and crash events get a severity weight and a time weight (recent events count more). Those add up to a measure. Then you're compared against a peer group of similarly-sized carriers and given a percentile from 0 to 100. Higher is worse.
Intervention thresholds
When a BASIC crosses its intervention threshold, FMCSA can take action:
- Warning Letter when a BASIC crosses threshold
- Focused Investigation if it stays above
- Compliance Review if it stays above for longer
Thresholds vary by BASIC:
- Unsafe Driving, HOS Compliance, Crash Indicator: 65 (general carriers)
- Driver Fitness, Controlled Substances, Vehicle Maintenance: 80
- HazMat: 80
Passenger carriers and HazMat carriers have lower thresholds — you can pull yours up in the SMS portal.
The peer-group catch
Your percentile depends on how big your peer group is. Small carriers get jumpy scores — one bad inspection can shift a percentile by 30 points. Don't panic at month-over-month volatility on a low-data carrier; look at the 12-month trend.
What to fix first
Look at which BASIC is closest to its threshold. That's the one that triggers intervention. The fix is usually not glamorous: train the driver who's getting the speeding tickets, replace the brake pads on the truck that keeps showing up in Vehicle Maintenance OOS, file the DataQ on the wrongly-coded inspection.
Where Patron lives
We monitor your SMS scores monthly. When a BASIC starts trending toward threshold, we run a targeted remediation — driver coaching, file cleanup, DataQ challenges, vehicle priorities. The goal is to keep every BASIC well below intervention so FMCSA never has a reason to send a letter.
Reading your SMS isn't hard once you know what you're looking at. And once you read it, you can fix it.