Safety Measurement System

The Safety Measurement System (SMS) is FMCSA's data-driven algorithm that quantifies the on-road safety performance of motor carriers and prioritizes them for interventions such as warning letters, targeted investigations, and compliance reviews. SMS evaluates carriers across seven Behavior Analysis and Safety Improvement Categories (BASICs): Unsafe Driving, Hours-of-Service Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, Hazardous Materials Compliance, and Crash Indicator. Each BASIC generates a percentile score from 0–100 based on the carrier's safety event history over a rolling 24-month window, weighted by time (recent violations count more) and severity. Intervention thresholds vary by BASIC and carrier type: for general freight carriers, Unsafe Driving triggers at the 65th percentile, Vehicle Maintenance at the 80th, and HOS Compliance at the 65th. Carriers exceeding these thresholds face escalating enforcement actions that can ultimately result in out-of-service orders suspending operating authority. The financial stakes are enormous — a compliance review resulting in a conditional or unsatisfactory safety rating can disqualify a carrier from government contracts, void insurance coverage provisions, and trigger customer contract termination clauses. Carriers with poor SMS scores also face 15–30% higher insurance premiums at renewal. Fleet operators can proactively manage their SMS profiles by monitoring DataQs for erroneous violation records (successful challenges reduce scores), implementing telematics-driven driver coaching programs targeting high-weighted violation categories, and maintaining robust vehicle inspection protocols to keep OOS rates below national averages.