Helm Michigan Trucking Pulse: Methodology

Version: 1.1.5

Sources

• FMCSA Vehicle Inspection File, data.transportation.gov dataset fx4q-ay7w (SODA API, free).
• FMCSA Crash File, dataset aayw-vxb3.
• US Census Bureau 2020 county FIPS codes for Michigan county names.

FMCSA file dates (Socrata rowsUpdatedAt at build time, ET)

• fx4q-ay7w: file updated 2026-10-25 (07:07 ET)
• aayw-vxb3: file updated 2026-10-25 (07:45 ET)
• az4n-8mr2: file updated 2026-10-25 (06:56 ET)

Measures

• Helm out-of-service share (Helm's measure, NOT FMCSA's official OOS rate): inspections with oos_total > 0 divided by all inspections, by insp_date month and state of inspection (report_state). US = all records.
• Crashes: crash records by report_date month and state of crash. Only months whose last day is at least 90 days before the pull date. Counts may still rise.
• Month selection: latest inspection month is the latest full month ending at least 14 days before the pull.
• Geography: where the inspection or crash happened, not where the carrier is based.
• Suppression: a county rate is suppressed when the county has 1 to 29 inspections. A county with 0 coded inspections shows 0 with the reason above. In the census snapshot, counts of 1 to 9 are suppressed and 0 is shown as 0.
• Rounding: all percentages and changes are rounded half up to 1 decimal (for example 17 of 80 = 21.25% shows as 21.3%).
• Pinned pull: each edition is built from one cached pull. Before release every headline query (latest month, prior month and year-ago month for inspections, and the crash month and its year-ago month, for MI, OH, IN and US) is re-run uncached. Every run, pass or fail, is logged in guard_log.csv, and the build stops on any difference.
• Counties: all 83 Michigan counties are listed. A 0 means no inspections coded to this county, not a confirmed zero. St. Clair (FIPS 147) had 55 to 99 inspections a month Sep 2025 to Apr 2026 and none coded May to Oct 2026; St. Joseph (149) shows the same break. Gladwin, Huron and Lake have sporadic months with small counts, so a zero there is plausible but also unconfirmed. Michigan records with a blank county code start in April 2026 (4 records, all from reporting office 1DCH001), and county codes 147 and 149 disappear from May 2026. Blank-county records total 430 from April to September 2026 (80 in September); they count in the state total only. Of those 430, 89 use location codes 340R2, 340R3, 340R5 and 341, which from January 2025 to March 2026 were coded only to county 147 (St. Clair); we do not assign them to a county. Through April 2026, office 3MIS001 coded 1,768 of the 1,769 county 147/149 records (the other was one 1DCH001 record in April 2025); 3MIS001 has no Michigan records after April 2026, and 1DCH001 has filed all Michigan records since May 2026. Method: SODA group-by queries on fx4q-ay7w (report_state='MI'; county_code, location, source_office by month), listed in fmcsa_report/queries_used.txt, run 2026-10-25.
• Revisions: FMCSA data is preliminary. Each edition re-pulls all months, and archived editions are never changed.
• Scope: safety and enforcement statistics only. Not tied to any carrier, any insurance price or any underwriting decision.
• Safety ratings: counts only, labeled satisfactory, conditional, unsatisfactory or No rating listed. No rating listed means the carrier has no FMCSA safety rating on file. A new-entrant safety audit does not produce a safety rating.
• Census snapshot: each run freezes aggregated Company Census totals (by state, status, rating; Michigan by county and status) in pulse/snapshots/YYYY-MM-DD/. Counts under 10 suppressed. No carrier-level rows.
• Attribution: Helm Partners analysis of FMCSA public data. Statements attributed to Helm Partners. Any statement about the Pulse is from Helm Partners, not a named person.
• License: Source data: FMCSA and other U.S. government agencies (public domain). Our analysis, charts and text: CC BY 4.0, Helm Partners. Please credit "Helm Partners, Helm Michigan Trucking Pulse" and link to this page.
• Status: We are not licensed in any state yet. Our Michigan license is pending. We do not quote or sell insurance until licensed. This page is general information.

Reproduce

python3 build.py in the preview folder. Every number in data.csv has a query_id that maps to an exact URL in queries_log.csv.

Changelog

• 1.1.5 (2026-10-25): QA follow-ups. County caveat states blank-county records start April 2026 (4) and codes 147/149 end May 2026; replaced the site-code claim with the verified 89 of 430 (location codes 340R2, 340R3, 340R5, 341), with method cited; added the 3MIS001 to 1DCH001 reporting-office change; a rate-limited guard run now logs aborted_rate_limit; build.py --preview-only regenerates pulse/latest without touching the dated archive.
• 1.1.4 (2026-10-25): county zeros relabeled "no inspections coded to this county" with a source coding gap caveat (St. Clair, St. Joseph); guard covers all headline queries and logs every run; suppression wording matches data; round half up rule; source file update times shown.
• 1.1.3 (2026-10-25): QA fix. Fresh pinned pull after a transient API read showed 4,353 Michigan September inspections (correct: 4,351). Added headline re-verification, dataset_versions.csv, and all 83 counties in data.csv, FMCSA file-updated dates, new license line.
• 1.1.2 (2026-10-25): Compliance fixes (pulse-20261025.md): label 'No rating listed', new-entrant audit sentence (PU1), visible license line (PU2), status line near top (PU3), 'Statements attributed to Helm Partners'.
• 1.1.1 (2026-10-25): changed the no-rating label and added a definition line.
• 1.1.0 (2026-10-25): added dated census snapshot, no-rating wording, Helm Partners attribution, no underwriting link.
• 1.0.0 (2026-10-25): first preview edition.