{
  "vercy": "1.0-draft",
  "publication": {
    "status": "research-draft",
    "adjudicationStatus": "unreviewed",
    "publishableCanonical": false,
    "generatedAt": "2026-09-13T05:02:28Z",
    "providers": [
      "Claude"
    ],
    "breadth": "written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify",
    "pass": 2,
    "wave": 3,
    "engine": "claude",
    "enrichment": {
      "pass": 3,
      "engine": "claude",
      "producedAt": "2026-10-06T10:00:00Z",
      "ingestedAt": "2026-10-06T07:08:14+00:00",
      "fields": [
        "agent_conduct",
        "ethics",
        "owners"
      ]
    },
    "gate": {
      "passed": true,
      "version": "1.0",
      "at": "2026-10-06T19:51:54+00:00",
      "evidence": [
        "completeness 1.00",
        "sense: Wikidata description",
        "2 live sources",
        "review by codex: pass"
      ]
    }
  },
  "metaModel": {
    "id": "THING-Q1643599",
    "registryId": "vr.tr.grade-separation",
    "name": "grade separation",
    "version": "0.2.0-wave.3",
    "entryKind": "thing",
    "family": "Thing Registry",
    "domain": [
      "PHY.BLT"
    ],
    "status": "research-draft"
  },
  "canonicalUrl": "https://ver.cy/models/thing/q1643599/",
  "model": {
    "registry_id": "vr.tr.grade-separation",
    "name": "grade separation",
    "purpose": "Let an agent explain grade separation and its forms, relay design and benefits from transport engineering sources, describe interchange types and rail applications, and distinguish grade separation from at-grade junctions, level crossings and traffic signals.",
    "definition": "A method of aligning a junction of two or more roads, railways or paths at different heights so that traffic streams cross without intersecting, using bridges, flyovers, underpasses or tunnels, often combined with ramps to form an interchange; grade separation removes conflicting movements, increases capacity and safety, and is used at motorway interchanges, rail-over-road crossings and railway flying junctions, at the cost of land, height and expense.",
    "what_it_is_for": "Separating crossing traffic streams vertically.",
    "affordances": [
      "explain forms",
      "relay design and benefits",
      "describe interchange types",
      "distinguish from at-grade junctions"
    ],
    "distinguishing_features": [
      "Vertical separation",
      "No crossing conflicts",
      "Ramps for connection",
      "High cost"
    ],
    "appearance": "A bridge or underpass carrying one route over or under another, often with ramps.",
    "visual_identification": [
      "Junction with routes at different levels",
      "Flyovers, underpasses, interchanges, flying junctions, rail-over-road bridges",
      "At-grade junctions cross on one level; level crossings are at-grade rail-road crossings"
    ],
    "physical_properties": [
      {
        "quantity": "typical road clearance",
        "typical_range": "about 4.5-5.5",
        "unit": "m",
        "note": "varies by country"
      },
      {
        "quantity": "typical rail clearance",
        "typical_range": "about 5-7",
        "unit": "m",
        "note": "electrified lines higher"
      }
    ],
    "families_and_kinds": [
      "simple overpasses and underpasses without connection",
      "road interchanges such as diamond, cloverleaf, stack and roundabout interchanges",
      "rail flying junctions and dive-unders",
      "rail-over-road and road-over-rail bridges",
      "pedestrian and cycle bridges and subways"
    ],
    "related_models": [
      {
        "relation": "is a kind of",
        "target": "road junction",
        "why": "in registry terms"
      },
      {
        "relation": "is implemented by",
        "target": "interchange",
        "why": "with ramps"
      },
      {
        "relation": "uses",
        "target": "overpass",
        "why": "or underpass structures"
      },
      {
        "relation": "is contrasted with",
        "target": "at-grade intersection",
        "why": "on one level"
      }
    ],
    "identifiers": [],
    "standards_and_regulation": [
      "Road design standards such as AASHTO and national design manuals",
      "Railway clearance and structure gauge standards",
      "Environmental and planning approval"
    ],
    "failure_modes_and_hazards": [
      "Bridge strikes from over-height vehicles",
      "Community severance and land take",
      "Confusing interchanges with grade separation in general"
    ],
    "in_scope": [],
    "out_of_scope": [],
    "characteristics": [],
    "agent_conduct": {
      "may": [
        "Explain grade separation and its forms such as flyovers, underpasses and interchanges.",
        "Report structural or traffic problems at a grade-separated junction to the road or rail authority."
      ],
      "must_not": [
        "Enter tunnels, bridges or ramps where pedestrians or unauthorized vehicles are prohibited.",
        "Present a grade separation design as safe without the engineering review required.",
        "Ignore impacts on communities divided by elevated roads or railways."
      ],
      "requires_human": [
        "Approving changes to traffic flow or closures at an interchange."
      ]
    },
    "ethics": {
      "considerations": [
        "Grade separation saves lives at crossings but can cut neighbourhoods apart.",
        "Underpasses and footbridges need to be accessible and safe for pedestrians."
      ],
      "affected_parties": [
        "Road and rail users",
        "Pedestrians and cyclists",
        "Neighbouring communities"
      ]
    },
    "owners": {
      "steward": "The road or railway authority that owns the structures.",
      "master_systems": [
        "Road and rail asset registers"
      ]
    }
  },
  "sources": [
    {
      "id": "wikidata",
      "title": "Wikidata item Q1643599: grade separation",
      "url": "https://www.wikidata.org/wiki/Q1643599",
      "url_status": "live",
      "what_it_supports": "identity and sense of the item",
      "checked_by": "wikidata-api"
    },
    {
      "id": "wikipedia-en",
      "title": "Wikipedia: Grade separation",
      "url": "https://en.wikipedia.org/wiki/Grade_separation",
      "url_status": "live",
      "what_it_supports": "general description of the item",
      "checked_by": "wikidata-api sitelink"
    }
  ],
  "structure": {
    "bundles": [
      {
        "id": "understand",
        "name": "Understand",
        "description": "What grade separation is.",
        "rationale": "Definition.",
        "layers": [
          {
            "id": "definition",
            "name": "Definition",
            "description": "Definition.",
            "findings": [
              {
                "id": "definition-finding",
                "name": "Definition",
                "description": "Definition.",
                "questions": [
                  {
                    "text": "What is grade separation, and how does it differ from at-grade junctions and level crossings?",
                    "kind": "definition"
                  },
                  {
                    "text": "Is the question about grade separation, a specific interchange type or a level crossing?",
                    "kind": "boundary"
                  }
                ]
              }
            ]
          },
          {
            "id": "forms",
            "name": "Forms",
            "description": "Forms.",
            "findings": [
              {
                "id": "forms-finding",
                "name": "Forms",
                "description": "Forms.",
                "questions": [
                  {
                    "text": "What are overpasses, underpasses, interchanges and flying junctions?",
                    "kind": "definition"
                  },
                  {
                    "text": "Which entry fits the specific form?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "design",
        "name": "Design",
        "description": "Design.",
        "rationale": "Practice.",
        "layers": [
          {
            "id": "road",
            "name": "Road",
            "description": "Road interchanges.",
            "findings": [
              {
                "id": "road-finding",
                "name": "Road",
                "description": "Road.",
                "questions": [
                  {
                    "text": "How are diamond, cloverleaf, stack and other interchanges designed and chosen?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which references are standard?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          },
          {
            "id": "rail",
            "name": "Rail",
            "description": "Rail applications.",
            "findings": [
              {
                "id": "rail-finding",
                "name": "Rail",
                "description": "Rail.",
                "questions": [
                  {
                    "text": "How are flying junctions and level crossing removals designed?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which sources are cited?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "evaluate",
        "name": "Evaluate",
        "description": "Benefits and costs.",
        "rationale": "Regulation.",
        "layers": [
          {
            "id": "benefits",
            "name": "Benefits",
            "description": "Benefits.",
            "findings": [
              {
                "id": "benefits-finding",
                "name": "Benefits",
                "description": "Benefits.",
                "questions": [
                  {
                    "text": "What safety and capacity benefits does grade separation bring, as studies report?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits road safety?",
                    "kind": "action"
                  }
                ]
              }
            ]
          },
          {
            "id": "costs",
            "name": "Costs",
            "description": "Costs and impacts.",
            "findings": [
              {
                "id": "costs-finding",
                "name": "Costs",
                "description": "Costs.",
                "questions": [
                  {
                    "text": "What are the costs, land take and community impacts, with positions attributed?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits urban planning?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "context",
        "name": "Context",
        "description": "Examples and history.",
        "rationale": "Context.",
        "layers": [
          {
            "id": "examples",
            "name": "Examples",
            "description": "Examples.",
            "findings": [
              {
                "id": "examples-finding",
                "name": "Examples",
                "description": "Examples.",
                "questions": [
                  {
                    "text": "What are notable grade-separated junctions and level crossing removal programmes?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits the specific junction?",
                    "kind": "action"
                  }
                ]
              }
            ]
          },
          {
            "id": "history",
            "name": "History",
            "description": "History.",
            "findings": [
              {
                "id": "history-finding",
                "name": "History",
                "description": "History.",
                "questions": [
                  {
                    "text": "How did grade separation develop with railways and motorways?",
                    "kind": "provenance"
                  },
                  {
                    "text": "Which entry fits the history of road transport?",
                    "kind": "action"
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  "openQuestions": [
    "Should interchange and flying junction be separate entries?",
    "How should engineering standards be linked?",
    "How should notable examples be linked?"
  ],
  "statistics": {
    "bundles": 4,
    "layers": 8,
    "findings": 8,
    "questions": 16
  }
}