# The pass that started as a fail

> A clean pass, a repair at the station and a later retest describe different MOT journeys.

- Category: Transport
- Canonical: [https://londongraph.com/story/the-pass-that-started-as-a-fail](https://londongraph.com/story/the-pass-that-started-as-a-fail)
- Machine-readable record: [https://londongraph.com/data/story/the-pass-that-started-as-a-fail](https://londongraph.com/data/story/the-pass-that-started-as-a-fail)
- Latest contributing release: 2026-08-03T13:41:34.659Z

An MOT headline changes when repaired-at-station results or retests are folded into pass counts. The evidence below separates initial class 4 tests, vehicle age and model cohorts so a high-volume administrative extract does not become a simplistic reliability league table.

## Evidence

### Initial-test outcomes

Clean passes, passes after rectification at the station and failures shown as distinct outcomes.

- The dataset is not available on this deployment; no value is substituted.
- Dataset: `mot-outcome-mix`
- Explore: [does-london-pass-its-mot](https://londongraph.com/g/does-london-pass-its-mot)

### London postal district history

Initial class 4 clean-pass and failure rates through the published annual extracts.

- Current computed headline: London postal district — 85.61 % of initial tests passed (2025)
- Great Britain: 77.57 % of initial tests passed
- Release: 2024–2025
- Dataset: `mot-pass-rate-history`
- Explore: [does-london-pass-its-mot](https://londongraph.com/g/does-london-pass-its-mot)

### Fleet age at test

The age distribution of class 4 vehicles brought for an initial test in the London postal district.

- The dataset is not available on this deployment; no value is substituted.
- Dataset: `mot-fleet-age`
- Explore: [what-london-drives-to-the-test-centre](https://londongraph.com/g/what-london-drives-to-the-test-centre)

### What fails

Failure-item records grouped into the published inspection systems after a London test-ID join.

- The dataset is not available on this deployment; no value is substituted.
- Dataset: `mot-failure-systems`
- Explore: [what-london-cars-fail-on](https://londongraph.com/g/what-london-cars-fail-on)
- Caveat: One failed test can contain several recorded reasons.

## Interpretation

MOT results describe vehicles presented for testing, not every vehicle on London's roads. Model comparisons are not reliability rankings because fleet age, mileage, maintenance and owner use differ.

Every numerical claim is computed from the current versioned datasets at render time. Missing data is reported as missing rather than replaced.

## Sources

- [DVSA](https://open.data.dvsa.gov.uk/mot-anonymised/index.html)