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Data Methodology & Verification

How We Build and Verify Our Data

TyreMap is only useful if you can trust the number on the page. This document explains exactly where our data comes from, how a record earns its place, who checks it, and how we keep it current. Nothing here is aspirational — it describes the workflow and the tooling that actually run behind the site.

Our coverage spans driving regulations for 195 countries and all 50 US states, and a dedicated dataset of 596 European emission-zone records across 30 countries. This page focuses mostly on the emission-zone dataset, because it is the most detailed, the most fast-moving, and the one where a wrong answer costs a real driver a real fine.

What We Track

Each emission-zone record is a structured entry, not a paragraph of prose. Every zone carries the same fields so that nothing important is left vague:

  • Zone type and name — Umweltzone, ZFE, ZTL, LEZ, ULEZ, Milieuzone, and so on
  • Minimum emission standards — the minimum Euro class required for petrol and for diesel vehicles
  • Sticker or permit — what you actually need on the windscreen (e.g. the German green Umweltplakette, the French Crit’Air) or whether none is required
  • Fine — the penalty for entering without compliance
  • Enforcement method — ANPR cameras, police spot checks, or both
  • Operating hours — 24/7 or specific windows
  • Exemptions — electric, hydrogen, historic vehicles, and other local exceptions
  • Status — whether the zone is actually in force
  • Coordinates and active-since year — for the map and for context

Of the 596 records, 495 are active, 37 are planned, 9 have been postponed, 6 were cancelled, and 49 were announced but never enacted. We deliberately keep the non-active ones. When a driver asks “do I need a sticker for this city?”, the most valuable answer is often “no — that zone was cancelled” or “not yet — it starts next year.” Deleting those records would erase exactly the reassurance the reader came for.

Where the Data Comes From

587 of the 596 records link directly to an official source URL, stored with the record itself. We prioritise government and municipal publications over aggregators, and aggregators over encyclopaedias. In practice that means sources such as:

  • Germany — Umwelt-Plakette (the official sticker portal), the Umweltbundesamt (Federal Environment Agency), Bußgeldkatalog, and ADAC
  • France — service-public.fr, certificat-air.gouv.fr (the official Crit’Air service) and ecologie.gouv.fr
  • Italy — the Ministry of the Environment (mite.gov.it), the Automobile Club d’Italia (ACI), and regional environmental agencies (ARPA)
  • Spain — the Dirección General de Tráfico (DGT), MITECO, and the Boletín Oficial del Estado (BOE)
  • Netherlands — milieuzones.nl · Sweden — Transportstyrelsen · Denmark — the official miljøzoner service
  • United Kingdom — GOV.UK and the national Clean Air Zone vehicle-checker services
  • Cross-border reference — Urban Access Regulations in Europe (urbanaccessregulations.eu), the EU-supported clearing house for access schemes

Where an encyclopaedic source appears in our records, it is used only as a pointer toward a primary document — never as the sole basis for a published value. When two sources disagree, the official government publication wins, and the discrepancy is noted rather than silently averaged.

What Makes a Zone “Active”

A record is marked active only when an official source confirms the zone is currently in force with defined rules — a stated minimum Euro standard, a defined fine, and a real enforcement mechanism. A press release announcing a future scheme is not enough to mark a zone active; it is recorded as planned with its expected start. Schemes that were dropped are marked cancelled or never enacted. This is why our active count (495) is lower than our total (596): the gap is information, not omission.

How Verification Works

Every zone page exposes its own provenance. Three fields drive this:

  • verified_at / last_verified — the date the value was last checked against its source
  • next_review — when it is next due for a look
  • changelog — a dated, human-readable history of what changed and when

Those dates power the freshness badge you see at the top of every zone page. It is colour-coded by age: green when the data was verified within the last 14 days, amber at 14–30 days (review due), and red beyond 30 days, where it is explicitly labelled re-verifying. The badge is generated from the real verification date — it cannot show “verified today” unless the record actually carries a recent date.

The Weekly Freshness Engine

Verification is not a one-off. An automated job runs every week and re-checks a batch of the official source URLs behind our records. Its design has one rule that matters more than any other, and it is a hard guarantee:

The engine never writes a scraped or guessed value into the dataset.

It can only do three things. It can confirm freshness — when an official page is unchanged, it records that the data derived from it was re-checked, without touching the value. It can flag a change — when a source page has changed, it adds that record to a human review queue and leaves the last verified value live. Or it can regenerate downstream artifacts — the map and tool data are recompiled deterministically from the dataset, never re-invented. Because it is structurally incapable of publishing an extracted value, a malformed source page or a garbled download can never corrupt what you read.

The guiding principle is simple: stale-but-correct beats fresh-but-wrong. The engine also behaves as a good web citizen — it identifies itself honestly (as TyreMapBot), respects robots.txt, uses conditional requests, and rate-limits itself so it never hammers a government server.

Human Review and Corrections

When the engine flags a change, a person resolves it — reading the official source and updating the value, the changelog, and the verification date together. Cities that have several related records (a general zone plus specific sub-zones) are synchronised as a set so they never drift apart. Records are corrected or re-labelled, never quietly deleted.

Found an Error? Tell Us

We would rather hear about a mistake than have you drive on it. If a value looks wrong, email contact@tyremap.com or use our contact page with the page in question, the incorrect information, and — if you have one — a link to an official source. We aim to verify and apply genuine corrections within one week.

Limitations

Regulations change, sometimes overnight, and local exemptions and enforcement practices vary more than any dataset can fully capture. We link the official source on every zone page for exactly this reason: treat TyreMap as the fast, structured first answer, and confirm the detail against the linked authority before you drive. For the full statement of scope and liability, see our disclaimer.