{
 "schemaVersion": "1.0.0",
 "constitutionVersion": "1.0.0",
 "createdAt": "2026-08-12T00:00:00Z",
 "description": "Append-only Evidence Passport records. Old revisions are immutable; corrections create a new revision and preserve the previous permalink.",
 "entity": {
  "type": "project",
  "id": "london-ulez",
  "title": "Ultra Low Emission Zone (ULEZ)",
  "canonicalUrl": "https://1001smartcities.org/projects/london-ulez/"
 },
 "currentRevisionId": "2026-08-20-source-dates",
 "revisions": [
  {
   "id": "2026-08-20-source-dates",
   "createdAt": "2026-08-20T19:16:27Z",
   "effectiveAt": "2026-07-17",
   "changeType": "baseline",
   "summary": "Created the first structured Evidence Passport with 1 claim and 6 source dossiers.",
   "preparedBy": {
    "type": "automation",
    "label": "AI-assisted evidence preparation",
    "humanApproved": false
   },
   "review": {
    "status": "unreviewed",
    "by": null,
    "date": null,
    "note": "Awaiting operator and domain-expert review; publication of this revision implies neither."
   },
   "changes": [
    {
     "operation": "add",
     "path": "/evidencePassport",
     "summary": "Added claim-level evidence mapping and source dossiers."
    },
    {
     "operation": "add",
     "path": "/revisionHistory",
     "summary": "Established a permanent, hash-addressed baseline revision."
    }
   ],
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   "snapshot": {
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    "assurance": {
     "status": "unreviewed",
     "scope": "evidence-passport-revision",
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     "machineChecks": [
      "schema",
      "publication-diff-contract",
      "material-project-fingerprint",
      "claim-text-drift",
      "source-reference-resolution",
      "complete-source-dossier",
      "snapshot-hash"
     ]
    },
    "projectState": {
     "status": "live",
     "outcome": "succeeded",
     "evidenceGrade": "peer-reviewed",
     "timeline": {
      "started": 2019,
      "ended": null
     }
    },
    "governance": {
     "operator": "Transport for London (TfL)",
     "actorTypes": [
      "utility"
     ],
     "fundingModel": "public",
     "fundingDescription": null,
     "cost": null,
     "ownership": null,
     "decisionRights": null,
     "exitConditions": null
    },
    "claims": [
     {
      "id": "clm-25dbbb66a2336acc",
      "field": "impact",
      "text": "An independent peer-reviewed study (Elliott et al., npj Clean Air, 2025) measured a more modest ~19.6% NO2 cut at central-London traffic sites after the 2019 zone, and no detectable effect from the 2023 outer expansion",
      "statementKind": "quantitative",
      "textMode": "verbatim-from-project-record",
      "mappingStatus": "mapped",
      "sourceRefs": [
       "src-22d3b2b43309a95b"
      ],
      "supportNote": null,
      "caveat": "TfL's own One Year Report estimates larger effects — roadside NO2 27% lower across London in 2024 and 54% lower in central London.",
      "interpretation": {
       "added": false,
       "interpolation": false,
       "note": "The passport copies the published claim and its recorded source mapping without adding a conclusion."
      }
     }
    ],
    "sources": [
     {
      "id": "src-97ebd5d47555d6c4",
      "title": "Transport for London (authority)",
      "url": "https://tfl.gov.uk/modes/driving/ultra-low-emission-zone",
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       "classification": "not-classified"
      },
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      "role": "background",
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      "temporal": {
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       "updatedAt": null,
       "sourceCheckedAt": null,
       "recordLastVerifiedAt": "2026-07-17",
       "dossierCreatedAt": "2026-08-20",
       "retrievedAt": null,
       "status": "record-date-only"
      },
      "locator": {
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       "value": "Official page by the city or public authority behind the project.",
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      },
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      }
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      "id": "src-e88e34ca2954c7d0",
      "title": "Londonist (press)",
      "url": "https://londonist.com/london/transport/ulez-expansion-august-2023-what-when-where",
      "publisher": {
       "name": null,
       "domain": "londonist.com",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "background",
      "claimRefs": [],
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       "recordLastVerifiedAt": "2026-07-17",
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       "retrievedAt": null,
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      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "News coverage of the August 2023 London-wide expansion.",
       "exact": false
      },
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     },
     {
      "id": "src-db296f845b951877",
      "title": "Centre for Cities (trade)",
      "url": "https://www.centreforcities.org/blog/londons-ulez-expansion-is-bold-action-more-cities-need/",
      "publisher": {
       "name": null,
       "domain": "centreforcities.org",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "background",
      "claimRefs": [],
      "temporal": {
       "publishedAt": "2022-12-01",
       "updatedAt": "2022-12-06",
       "sourceCheckedAt": null,
       "recordLastVerifiedAt": "2026-07-17",
       "dossierCreatedAt": "2026-08-20",
       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "Industry publication reporting on the project.",
       "exact": false
      },
      "preservation": {
       "archiveUrl": null,
       "archivedAt": null,
       "contentHash": null,
       "status": "not-captured"
      }
     },
     {
      "id": "src-53095389fb730e09",
      "title": "University of Birmingham (research)",
      "url": "https://www.birmingham.ac.uk/news/2025/londons-ulez-cut-air-pollution-high-vehicle-compliance-left-little-room-for-post-expansion-gains",
      "publisher": {
       "name": null,
       "domain": "birmingham.ac.uk",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "background",
      "claimRefs": [],
      "temporal": {
       "publishedAt": "2025-10-22",
       "updatedAt": null,
       "sourceCheckedAt": null,
       "recordLastVerifiedAt": "2026-07-17",
       "dossierCreatedAt": "2026-08-20",
       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "Independent study (npj Clean Air, Oct 2025): the 2019 zone cut roadside NO2 quickly; high prior compliance left little gain from the 2023 expansion.",
       "exact": false
      },
      "preservation": {
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       "archivedAt": null,
       "contentHash": null,
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      }
     },
     {
      "id": "src-f761866c1d1f34a3",
      "title": "TfL — ULEZ One Year Report (authority)",
      "url": "https://content.tfl.gov.uk/london-wide-ulez-one-year-report.pdf",
      "publisher": {
       "name": null,
       "domain": "content.tfl.gov.uk",
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      },
      "sourceType": "pdf",
      "language": "und",
      "role": "background",
      "claimRefs": [],
      "temporal": {
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       "sourceCheckedAt": null,
       "recordLastVerifiedAt": "2026-07-17",
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       "retrievedAt": null,
       "status": "record-date-only"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "Official evaluation of the London-wide zone, published March 2025 — source of the impact figures.",
       "exact": false
      },
      "preservation": {
       "archiveUrl": null,
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       "contentHash": null,
       "status": "not-captured"
      }
     },
     {
      "id": "src-22d3b2b43309a95b",
      "title": "Elliott et al. 2025, npj Clean Air (peer-reviewed)",
      "url": "https://www.nature.com/articles/s44407-025-00030-9",
      "publisher": {
       "name": null,
       "domain": "nature.com",
       "classification": "not-classified"
      },
      "sourceType": "web-page",
      "language": "und",
      "role": "claim-evidence",
      "claimRefs": [
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      ],
      "temporal": {
       "publishedAt": "2025-10-22",
       "updatedAt": null,
       "sourceCheckedAt": null,
       "recordLastVerifiedAt": "2026-07-17",
       "dossierCreatedAt": "2026-08-20",
       "retrievedAt": null,
       "status": "publication-and-record-dates-recorded"
      },
      "locator": {
       "type": "descriptive-source-note",
       "value": "Independent causal study: ~19.6% NO2 cut at central-London traffic sites after the 2019 ULEZ; no detectable effect from the 2023 outer expansion.",
       "exact": false
      },
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    ],
    "coverage": {
     "claimsTotal": 1,
     "claimsMapped": 1,
     "sourcesTotal": 6,
     "sourcesUsedByClaims": 1,
     "sourcesWithPublicationDate": 3,
     "sourcesWithArchive": 0,
     "sourcesWithExactLocator": 0,
     "sourcesWithContentHash": 0
    },
    "limits": [
     "Publisher names and source languages have not yet been classified; domains are recorded without guessing.",
     "Existing source notes are descriptive locators, not page- or paragraph-exact citations.",
     "A missing archive, publication date or content hash is shown as null rather than inferred.",
     "The project-level evidence grade ranks the strongest source in the entry; it is not a truth score for every claim."
    ]
   }
  }
 ]
}