{"schemaVersion":"1.0","type":"DataStory","id":"the-pass-that-started-as-a-fail","title":"The pass that started as a fail","description":"A clean pass, a repair at the station and a later retest describe different MOT journeys.","introduction":"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.","category":"Transport","canonical":"https://londongraph.com/story/the-pass-that-started-as-a-fail","markdown":"https://londongraph.com/story/the-pass-that-started-as-a-fail/index.html.md","updatedAt":"2026-08-03T13:41:34.659Z","caveat":"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.","evidence":[{"dataset":"mot-outcome-mix","graphSlug":"does-london-pass-its-mot","label":"Initial-test outcomes","text":"Clean passes, passes after rectification at the station and failures shown as distinct outcomes.","shape":"categories","graph":"https://londongraph.com/g/does-london-pass-its-mot","claim":null},{"dataset":"mot-pass-rate-history","graphSlug":"does-london-pass-its-mot","label":"London postal district history","text":"Initial class 4 clean-pass and failure rates through the published annual extracts.","shape":"latest","graph":"https://londongraph.com/g/does-london-pass-its-mot","claim":{"dataset":"mot-pass-rate-history","graphSlug":"does-london-pass-its-mot","label":"London postal district history","text":"Initial class 4 clean-pass and failure rates through the published annual extracts.","headlineLabel":"London postal district","value":85.61,"unit":"% of initial tests passed","period":"2025","comparisonLabel":"Great Britain","comparisonValue":77.57,"caveat":null,"release":{"updatedAt":"2026-08-03T13:41:34.659Z","resourceUrl":"https://open.data.dvsa.gov.uk/mot-anonymised/index.html","methodologyUrl":"https://www.data.gov.uk/dataset/c63fca52-ae4c-4b75-bab5-8b4735e1a4c9/anonymised-mot-tests-and-results","releaseLabel":"2024–2025","sourcePublishedAt":null,"resourceChecksum":null}}},{"dataset":"mot-fleet-age","graphSlug":"what-london-drives-to-the-test-centre","label":"Fleet age at test","text":"The age distribution of class 4 vehicles brought for an initial test in the London postal district.","shape":"categories","graph":"https://londongraph.com/g/what-london-drives-to-the-test-centre","claim":null},{"dataset":"mot-failure-systems","graphSlug":"what-london-cars-fail-on","label":"What fails","text":"Failure-item records grouped into the published inspection systems after a London test-ID join.","shape":"categories","caveat":"One failed test can contain several recorded reasons.","graph":"https://londongraph.com/g/what-london-cars-fail-on","claim":null}],"sources":[{"name":"DVSA","url":"https://open.data.dvsa.gov.uk/mot-anonymised/index.html","graphSlug":"does-london-pass-its-mot"}]}