CSA BASICs explained: the 7 categories, percentiles and intervention thresholds

CSA BASICs are the seven categories FMCSA uses to rank motor carriers' roadside and crash data: Unsafe Driving, Crash Indicator, Hours-of-Service Compliance, Vehicle Maintenance, Controlled Substances/Alcohol, Hazardous Materials Compliance and Driver Fitness. Each BASIC gets its own percentile from 0 to 100, where higher is worse. As of October 2026, the intervention thresholds for most trucking fleets are 65% or 80%.

BASIC stands for Behavior Analysis and Safety Improvement Category. The categories belong to the Safety Measurement System (SMS), the scoring engine inside FMCSA's Compliance, Safety, Accountability (CSA) program. This guide covers what each BASIC measures, how the percentile is built, when FMCSA steps in and what the public can see.

The seven CSA BASICs at a glance

The table below pulls each BASIC's scope from FMCSA's CSA site and its data rules from the SMS Methodology, version 3.21, revised June 2026. Both are current as of October 2026.

Sources: FMCSA CSA: Measure for scope and regulations; SMS Methodology v3.21, sections 2 and 3, for normalization, data minimums and thresholds; FMCSA SMS for public display. "Measure only" means the public sees the inspection data and the BASIC measure for a property carrier, but not its percentile.

Three cautions about the table. The data minimums are simplified: each BASIC also drops carriers with no recent violations, as described below. Hazmat and passenger carriers have lower thresholds. And a ninth item, the Insurance/Other Indicator, also feeds prioritization. It is not public and is built from investigation findings, such as missing insurance or crash report copies (Methodology, p. 2-2).

What each BASIC measures

Each BASIC groups violations of related rules. The SMS Methodology gives example violations for each one (pp. 2-1 to 2-2).

Unsafe Driving

Operating a commercial motor vehicle (CMV) "in a dangerous or careless manner." Examples include speeding, reckless driving, improper lane change, texting and not wearing a seat belt. Many of these violations are what start an inspection in the first place, so FMCSA measures this BASIC against carrier size, not inspection count.

Crash Indicator

The Crash Indicator is the only BASIC that does not use violations. It counts reportable crashes: those involving a CMV that cause a fatality or an injury, or need a vehicle towed, "regardless of the carrier or driver's role in the crash" (CSA: Measure). Crashes found not preventable through FMCSA's review program are listed as "Reviewed – Not Preventable" and left out of the measure. Our guide to preventable vs non-preventable crashes explains that review.

Hours-of-Service Compliance

Driving while ill or fatigued, or breaking the HOS limits and the records of duty status rules. FMCSA's examples include permitting a property-carrying driver to drive more than 11 hours and failing to keep records of duty status for 6 months.

Vehicle Maintenance

Failing to maintain a CMV and to prevent shifting loads, spilled cargo and overloading. Examples include inoperative brakes and lights, improper load securement and failing to make required repairs. FMCSA's CSA site says it includes "pre- and post-trip inspections, vehicle defects, and repairs."

Controlled Substances/Alcohol

Operating while impaired by alcohol, illegal drugs, or misused prescription or over-the-counter drugs. Failing to run a testing program counts here too, and so does an alcohol container in the cab, open or not.

Hazardous Materials Compliance

Unsafe handling of hazardous materials: missing marks, labels or placards, unsecured packages, leaks and missed cargo tank tests. Most general freight fleets never get a percentile here, because it uses only inspections of placarded loads.

Driver Fitness

Drivers unfit to operate because of training, experience or medical qualification. Examples include no valid CDL, being medically unqualified and missing driver qualification files. FMCSA notes this BASIC does not consider body mass index, weight or neck size.

How BASIC percentiles are calculated

A BASIC percentile compares your measure with carriers that have a similar amount of data. As of October 2026, the SMS Methodology builds it in five steps:

1. Severity weight. Each violation gets a weight from 1 to 10 within its BASIC, based on crash risk. Out-of-service violations get extra weight. Weights in different BASICs can't be compared (p. 2-4).
2. Time weight. Recent events count more. "Safety events older than 24 months are no longer used to assess a carrier's safety posture in the SMS" (p. 2-5).
3. Normalization. The weighted total is divided by your exposure: driver inspections, vehicle inspections or carrier size, as in the table above (pp. 2-5 to 2-6).
4. Peer groups. Carriers are sorted into "safety event groups" by their number of inspections or crashes. Unsafe Driving and Crash Indicator are also split into combination and straight-truck segments (p. 2-6).
5. Ranking. Within each group, measures are ranked from 0 to 100, "with 100 indicating the worst performance" (p. 2-7).

Two rules decide whether you get a percentile at all. First, you need the minimum data in the table. Second, in most BASICs a carrier is dropped if it has no violation in the past 12 months and none on its latest relevant inspection (pp. 3-13, 3-16, 3-21, 3-24). So a fleet with an old violation and a clean recent record may show no percentile in that BASIC.

Violations count even without a ticket. FMCSA uses violations recorded on a roadside inspection report "regardless of whether a State officer also issues a citation" (CSA: Measure). If a court dismisses a related citation, you can ask for the violation to be removed through DataQs (Methodology, p. 2-4). See our DataQs guide.

CSA BASIC intervention thresholds

An intervention threshold is the percentile at which FMCSA may prioritize a carrier for action. Because higher percentiles are worse, a lower threshold is stricter. As of October 2026, Table 2-2 of the SMS Methodology sets these:

FMCSA says the Unsafe Driving, Crash Indicator and HOS Compliance BASICs "have the strongest associations to crash risk," which is why their thresholds are lower (p. 2-8). A carrier can also be flagged in a BASIC for Acute or Critical violations found in an investigation within the past 12 months, whatever its percentile.

What happens when a BASIC is over the threshold

Being over a threshold makes a carrier a candidate for an intervention, not an automatic penalty. FMCSA's CSA site lists three groups of interventions (CSA: Intervene):

• Early contact: warning letters that describe the problem and the consequences of not improving.
• Investigation: an offsite investigation, an onsite focused investigation or an onsite comprehensive investigation.
• Follow-on: a Cooperative Safety Plan, a Notice of Violation or a Notice of Claim.

An investigation can lead to a safety rating, which is a separate process under 49 CFR 385. Our conditional safety rating guide covers what a rating means.

Which CSA BASICs can the public see?

For property carriers, the public sees inspection and crash data, investigation results and the measures for the public BASICs, but not the percentiles. Under the FAST Act of 2015, FMCSA took some property carrier results off public display; the measures still shown are "not based on relative comparison to other motor carriers," and the Crash Indicator and HM Compliance BASICs stay hidden from public view (FMCSA SMS). Property carriers must log in to see their own complete results. Passenger carrier percentiles in the public BASICs remain public.

FMCSA's site also warns: "Readers should not draw conclusions about a carrier's overall safety condition simply based on the data displayed in this system." Whether insurers use BASIC data is covered in does CSA score affect insurance.

How often BASICs update

The SMS updates once a month (CSA: Measure). On Oct. 20, 2026, the CSA home page showed data current as of Sept. 25, 2026, with the next update the week of Nov. 9, 2026 (csa.fmcsa.dot.gov).

CSA BASICs vs a safety rating

A BASIC percentile is a ranking. A safety rating is a legal finding. FMCSA has stated that "SMS is FMCSA's prioritization system" and "currently is not used in any way to generate" safety fitness determinations (88 FR 59489, Aug. 29, 2023). A carrier with high percentiles keeps its rating until a compliance review changes it.

Are the BASICs being replaced?

Not yet. In a notice published Nov. 20, 2024, FMCSA announced an enhanced SMS that would rename BASICs as "compliance categories," consolidate violations, simplify severity weights and revise thresholds (89 FR 91874). That notice said a follow-up Federal Register notice would announce the launch date. As of October 2026 we found no launch notice in the Federal Register, and FMCSA's live CSA site and its June 2026 methodology still use the seven BASICs. Status: announced, not launched.

Where to start if a BASIC is high

Start with the BASIC closest to its threshold. Check that every inspection and crash on your record is accurate, file DataQs requests for errors, and send eligible crashes for a preventability review. Then fix the control behind the violations: log audits for HOS, repair follow-through for Vehicle Maintenance, file reviews for Driver Fitness. Our step-by-step guide on how to improve a CSA score walks through each move.

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This article is general information, not legal advice. Confirm requirements against the current regulation text and with your compliance counsel.