How We Built This

This page explains, in plain English, what your report does and where every number comes from. The safety math is FMCSA's, taken from their published specifications. The insurance impact projection on top of it cites named industry sources and is reported as a range, not a quote.

1. What This Report Does

This report reads your USDOT's public FMCSA data the way an underwriter or broker reads it. It recomputes your Inspection Selection (ISS) value from the same inputs FMCSA uses, surfaces every percentile and intervention threshold that shapes that value, and projects the dollar impact carriers with similar profiles tend to see at renewal.

Two layers sit on top of each other:

Safety layer (FMCSA's math). Every step is modeled on FMCSA's published specifications, taken from the ISS Algorithm Description (December 2012) and SMS Methodology v3.20 (September 2025). Because some parts of the system (like historical peer-group statistics or specific FMCSA updates) are non-public, this recreation represents our best estimate and approximation.
Insurance impact layer. A range derived from ATRI's published cost data, the Texas Department of Insurance, and three named insurance-broker advisories. It is directional; not actuarial fact, not a quote.

2. The 14-Step ISS Recreation

ISS is not a single formula. It is a chain of 14 steps, each driven by public roadside-inspection data. Here is what each step does, in order, with the FMCSA section it comes from.

Step 1: Severity weighting. Every violation on a roadside inspection has a severity weight from 1 to 10. A blown-out tire weighs more than a missing log entry. The weights are published by FMCSA and never adjusted. Adjudicated violations are handled per FMCSA's published rule: dismissed violations are removed entirely; violations convicted of a different charge are reweighted to severity 1 (SMS Methodology v3.20, Table 2-1).

Step 2: Time weighting. Recent violations count more than old ones. The window is 24 months: newer events count 3×, mid-period 2×, and the oldest tier 1×. Anything older than 24 months ages out and stops counting (SMS Methodology v3.20, §3 "Time Weights").

Step 3: Severity cap. A single bad inspection cannot dominate the record. FMCSA caps the severity score per inspection so one catastrophic event does not overwhelm a year of clean roadsides.

Step 4: Per-BASIC measure formulas. FMCSA computes a "measure" for each of the seven BASICs (Behavior Analysis and Safety Improvement Categories): Unsafe Driving, Crash Indicator, Hours-of-Service Compliance, Vehicle Maintenance, Controlled Substances/Alcohol, Hazardous Materials Compliance, and Driver Fitness. The formula differs by BASIC:

Unsafe Driving and Crash Indicator are size-normalized by power units and vehicle-miles travelled; bigger fleets are not punished for having more exposure (SMS Methodology v3.20, Equations 3-1 and 3-3).
HOS Compliance, Vehicle Maintenance, Controlled Substances/Alcohol, HM Compliance, and Driver Fitness are normalized by inspection volume; a carrier with twenty inspections is compared apples-to-apples with a carrier with two hundred (SMS Methodology v3.20, Equations 3-5 through 3-9).

Step 5: Carrier classification. Every carrier is classified as Passenger, Hazardous Materials, or General. Classification changes which thresholds apply downstream; Passenger and HM carriers are held to stricter standards.

Step 6: Peer-group binning (Safety Event Groups). Carriers are sorted into peer groups by exposure; number of inspections, fleet size, or vehicle-miles travelled, depending on the BASIC. A five-truck carrier is benchmarked against other five-truck carriers, not against fleets of five-hundred. For Unsafe Driving and Crash Indicator, peers are also split by whether ≥70% of the fleet is combination tractors versus straight trucks; the other five BASICs are not split that way (SMS Methodology v3.20, Tables 3-3 through 3-20).

Step 7: Percentile rank within peer group. Each BASIC measure is ranked against the carrier's peer group to produce a percentile from 0 (best) to 100 (worst). The ranking pool is U.S.-domiciled interstate carriers plus HM carriers (SMS Methodology v3.20, §2). One outlier rule applies: if a carrier's Unsafe Driving measure is 250 or higher, FMCSA assigns percentile 100 and removes the carrier from the ranking pool entirely so erroneous data does not bias other carriers (SMS Methodology v3.20, §3 footnote 16).

Step 8: Intervention thresholds. A percentile crosses into "prioritized" territory at a published threshold that depends on the BASIC and the carrier type. For General-freight carriers:

Unsafe Driving / Crash Indicator / HOS Compliance; threshold at the 50th-60th-65th percentile band.
Vehicle Maintenance / Controlled Substances-Alcohol / Driver Fitness - threshold at the 65th-75th-80th percentile band.
HM Compliance; threshold at the 80th percentile.

Passenger and HM carriers carry stricter thresholds for the same BASICs (SMS Methodology v3.20, Table 2-2). FMCSA uses strict inequality: a percentile at the threshold is not prioritized; a percentile above it is.

Step 9: Prioritization. A BASIC is "prioritized" if its percentile is above threshold or if FMCSA recorded an Acute or Critical violation against that BASIC in the past twelve months. Prioritized BASICs are the ones inspectors and investigators flag first.

Step 10: Acute/Critical override. Investigation findings (not roadsides) can prioritize a BASIC by themselves, even without a high percentile. The "A/C" badge in your report flags this case.

Step 11: Group assignment (the 13 ISS groups). Every carrier with enough data lands in exactly one of thirteen groups. FMCSA evaluates the list in order and stops at the first match (ISS Algorithm Description, Appendix A, pages 14-15):

High-risk; meets FMCSA's separate high-risk criteria.
Three or more BASICs prioritized (best addressed at roadside).
Two BASICs prioritized.
One BASIC prioritized (best addressed at roadside).
HOS Compliance only above threshold.
Insurance / Other Serious Violation only; revoked authority, missing BIPD coverage, rejected insurance form, or a similar non-BASIC trigger. A carrier with clean BASICs can still land here if its insurance filings or operating authority are in trouble.
Vehicle Maintenance only.
HM Compliance only.
Driver Fitness only.
Controlled Substances/Alcohol only.
Unsafe Driving AND Crash Indicator both prioritized.
Single Crash or Unsafe Driving prioritized.
Has data, no prioritized BASIC; the clean tier.

Step 12: Out-of-Service Order override. If FMCSA has placed your operations under an Out-of-Service Order (OOSO) and that order has not been rescinded, the final ISS value is set to 100 regardless of every other input. A rescinded OOSO does not lock ISS at 100; only an active order does. Resolving an active OOSO is the only path off 100.

Step 13: Within-group ranking. Inside each group, carriers are ranked to produce the actual ISS value. Groups 1-5 receive values 75-99; groups 6-12 receive 50-74; group 13 receives 1-49 (ISS Algorithm Description, page 15).

There is a deliberate twist in group 13. The ranking sum for the clean tier uses only the five BASICs best addressed at roadside; HOS Compliance, Driver Fitness, Controlled Substances/Alcohol, Vehicle Maintenance, and HM Compliance. FMCSA explicitly excludes Unsafe Driving and Crash Indicator from this sum because, in their words, any value in these measures indicates a negative event occurred; a carrier with no crashes and no unsafe-driving violations is always considered safer than one with measured values, regardless of percentile (ISS Algorithm Description, page 15).

Step 14: Insufficient Data routing. New or small carriers without enough inspections to produce a reliable percentile are routed to a separate algorithm. See §4.

3. Why Your ISS Lands Where It Does

Picture a 12-truck general-freight carrier:

Unsafe Driving percentile 78, threshold 65 → over threshold, prioritized.
Vehicle Maintenance percentile 80, threshold 80 → at threshold, not strictly above, so not prioritized.
HOS Compliance percentile 45, threshold 65 → clean.
Crash Indicator percentile 30, threshold 65 → clean.
The remaining BASICs are clean or have no data.

This carrier has one prioritized BASIC, so group assignment routes it to Group 12 (single Unsafe-or-Crash). Within-group ranking by Unsafe Driving severity produces an ISS value typically in the Inspect band (75-99).

Drop Unsafe Driving below 65; by retraining drivers, challenging incorrect violations through DataQ, and accumulating clean roadsides; and the carrier moves into Group 13 (has-data, no-prioritized-BASIC, ISS 1-49). That is one or two band-jumps lower, not a marginal improvement.

This is why the "prioritized BASIC" chips on every report matter so much: each chip is a lever. Removing one prioritized BASIC can change the carrier's group, not just its rank within a group.

4. Insufficient Data Carriers

If a carrier is new or small, FMCSA may not have enough roadside-inspection data to produce a reliable percentile in one or more BASICs. The spec defines four cases (ISS Algorithm Description, pages 16-17):

Case 1A; exactly one inspection short of the minimum (the "1-away" case). One more clean roadside flips the carrier into the assessed pool.
Case 1B; borderline insufficient by a related driver-inspection criterion.
Case 2; zero roadside inspections on record.
Case 3; some inspections, but still below the minimum needed for a reliable percentile.

In all four cases the carrier is flagged "Insufficient Data" and excluded from percentile-based ranking. The FMCSA spec then includes a randomization step: one percent of insufficient-data carriers are randomly elevated to ISS 99 each monthly run. This report does not apply that random-elevation rule. Sparse-data carriers in this report are capped at the Optional band (50-74) instead, on the principle that a small carrier should not be force-elevated to a near-Inspect ISS by an unrelated random draw. Accumulating clean inspections is the only path to an assessed ISS.

5. The Insurance Impact Projection

The per-carrier insurance projection is three lines of math:

annual_baseline = annual_VMT × ATRI per-mile rate × state multiplier
dollar_low      = baseline × band_low_pct
dollar_high     = baseline × band_high_pct

The ATRI per-mile rate is selected by fleet size. ATRI publishes four tiers in An Analysis of the Operational Costs of Trucking: 2025 Update (July 2025):

1 power unit → no dollar clause. A single-truck owner-operator does not have a fleet-level premium pool to apply a percentage uplift against; only the percentage band shows.
2-25 power units → $0.210/mile, the small-fleet specialty rate (ATRI 2025 OC, page 43). ATRI reports two sub-tiers in this bucket ($0.210 and $0.213); the conservative low end is used.
26-100 power units → $0.130/mile, an interpolated mid-tier between small-specialty and industry-wide.
101-1,000 power units → $0.102/mile, the industry-wide 2024 average (ATRI 2025 OC, page 42).
More than 1,000 power units → no dollar clause. ATRI's Figure 20 documents that large-fleet insurance economics shift away from per-mile premium toward out-of-pocket crash costs and self-insured retention, so a flat percentage uplift understates the true cost of risk for these carriers (ATRI 2025 OC, page 44).

The state multiplier is applied only when a regulator-grade source has been bound. Today:

Texas → 1.10×, per the Texas Department of Insurance Commercial Auto Biennial Report, November 2024. TDI documents a 72.9% cumulative premium rise 2017-2024 (average premium $1,155 in 2017 to $2,020 in 2024), a 9.6% year-over-year rise in 2024 alone, and a commercial-auto combined ratio averaging 116% since 2011.
All other states → 1.0×. No state-specific multiplier is applied without a regulator-grade source. Speculative multipliers are excluded by design.

The band percentages (band_low_pct, band_high_pct) come from the carrier's BASIC profile (§6).

6. Where the Projection Bands Come From

The three premium bands are:

Clean band; no BASICs over threshold. No dollar clause; the projection surfaces only the industry baseline.
Approaching threshold (10-30%); one or more BASICs are nearing the intervention threshold. This range comes from industry-published guidance by Marquee Insurance Group (2025), COGO Insurance (2024), and Foley Carrier Services (2026).
Above threshold (30-50%+); one or more BASICs are over the intervention threshold. The same three broker advisories publish this range; some insurers in this band auto-decline rather than quote.

The actuarial backbone of these bands is FMCSA's own published crash-rate delta: carriers above intervention thresholds experience 79% higher crash rates than carriers below them, and carriers flagged on Unsafe Driving specifically experience 93% higher crash rates. Insurers cite this differential to justify BASIC-tied surcharges at renewal.

Two industry-wide pressures explain why the bands have widened in recent years:

Trucking insurance premium cost per mile has risen 36% over the past eight years while crash rates have declined for three consecutive years (ATRI 2025 OC, page 45).
The commercial-auto segment's combined ratio reached 108.5 in 2024 (loss-making for insurers, per AM Best), and ATRI's Top Industry Issues 2025 survey ranks Insurance Cost/Availability as the #3 industry-wide concern, with an Industry Concern Index of 69.0 (ATRI Top Industry Issues 2025, page 12).

Even clean carriers feel the pressure; carriers with prioritized BASICs feel it harder.

The projection is reported as a range, not a point estimate, because the actual outcome depends on which specific BASICs are flagged, your underwriter's appetite, your claims history, your fleet specifics, and your renewal cycle.

7. Looking Ahead: The FMCSA SMS Redesign

FMCSA has approved a major redesign of the Safety Measurement System but it has not yet been put into effect. The current methodology; v3.20, which this report follows; remains what FMCSA uses to prioritize carriers today. This was reverified directly against FMCSA's own portal in May 2026; FMCSA's official statement reads: "SMS is Still Being Used to Prioritize Carriers. Until the updated system is in effect, carriers should continue to use the current SMS website to monitor their safety performance."

When the redesign goes live, the following will change. None of these change your obligations today, but they are worth understanding now if you are planning a multi-year safety investment:

"BASICs" will be renamed "compliance categories." The seven categories themselves stay; only the term changes.
Controlled Substances/Alcohol will be folded into Unsafe Driving, along with every Operating-While-Out-of-Service violation regardless of which BASIC originally produced the OOS order. Drug-and-alcohol violations will no longer be a standalone category.
Vehicle Maintenance will split in two. "Vehicle Maintenance" will keep the violations a mechanic typically catches in a Level-1 inspection; a new "Vehicle Maintenance: Driver Observed" category will hold violations a driver could reasonably catch in a walk-around (Level-2).
Around 2,000 violation codes will collapse into about 116 violation groups. If you are cited for two violations in the same group during one inspection, FMCSA will count them as a single violation for scoring purposes. This change rewards carriers that fix the underlying issue instead of being penalized multiple times for the same problem.
Severity weights will simplify from a 1-10 scale to a 1-2 scale. A violation gets weight 2 if it is Out-of-Service or Driver-Disqualifying; otherwise it gets weight 1.
Safety event groups will be replaced by "proportionate percentiles." Today, if your inspection count crosses into a higher peer group, your percentile can jump sharply for reasons unrelated to your safety record. The new method uses your exact event count, so percentile changes will be smoother and more reflective of actual performance.
A 12-month recent-violation gate. You will only be ranked in HOS, Vehicle Maintenance, Vehicle Maintenance: Driver Observed, HM, and Driver Fitness if you have had at least one violation in that category in the past 12 months. Old violations alone will no longer prioritize you.
The utilization factor will extend from 200,000 to 250,000 VMT per power unit, which more accurately reflects how high-utilization carriers are reporting miles today.
HM Compliance will segment by Cargo-Tank vs Non-Cargo-Tank carriers. Driver Fitness will segment by Straight vs Combination, mirroring how Unsafe Driving and Crash Indicator are segmented today.
Intervention thresholds will move for Driver Fitness (80→90 percent for general carriers, 65→75 for passenger, 75→85 for HM) and Hazardous Materials (80→90 percent for all carrier types). The Vehicle Maintenance thresholds carry over to both new vehicle-maintenance categories.

FMCSA has not announced a date for when the new methodology will go live. Their own materials describe the program as currently in "Phase 2 of 3 - finalizing methodology, no changes implemented." This report will be updated to the new methodology only after FMCSA publishes the final specification and the production data feeds start using the new category structure.

If you want to preview how your carrier looks under the proposed new system, FMCSA hosts a free preview at csa.fmcsa.dot.gov/prioritizationpreview (login required).

8. What This Report Doesn't Claim

To keep this honest:

This is not FMCSA's official ISS. Only FMCSA's SAFER portal shows the official value. The math here is our best-estimate recreation based on FMCSA's published specifications and public data snapshots. Because some underlying parameters are non-public or fluctuate daily, this recreation is an approximation, and the official number wins; let us know and we'll reconcile.
This is not a PSP or FCRA consumer-reporting product. It is a reading of public FMCSA data, not a regulated background-check report.
The data is not redistributed in bulk. Each report is a single-carrier reading bound to one USDOT.
The dollar range is not a quote. It brackets the renewal impact carriers in similar bands have seen; not a specific carrier's outcome. Insurers will look at things outside the public data (claims, drivers, CAB scores, equipment).
The insurance impact projection is directional. The safety math is FMCSA's. The dollar range is industry guidance applied to it.

Sources

FMCSA, ISS-CSA Algorithm Description, December 2012.
FMCSA, SMS Methodology v3.20, September 2025.
ATRI, An Analysis of the Operational Costs of Trucking: 2025 Update, July 2025.
ATRI, Top Industry Issues 2025.
Texas Department of Insurance, Commercial Auto Biennial Report, November 2024.
AM Best, commercial-auto combined-ratio reporting (cited via ATRI 2025 Operational Costs).
Marquee Insurance Group (2025); COGO Insurance (2024); Foley Carrier Services (2026); industry-published premium-band guidance.
49 CFR §387.9; federal minimum financial responsibility for motor carriers.