{
  "catalog_id": 29,
  "title": "Traffic officers document an accident and direct following traffic",
  "source_template": "police",
  "summary": "Counterfactual rehearsal: two compact cars make gentle bumper contact at time 0. One officer surveys and photographs multiple sides of the vehicles while another holds ego and directs one following car through a separate northern channel. The incident vehicles remain in the ego corridor.",
  "focus_xy": [
    34.8,
    0
  ],
  "initial_review_time_s": 9,
  "ego_stop_x_m": 13,
  "ego_release_s": -1,
  "events": [
    {
      "time_s": -7,
      "label": "Officers are already nearby while a rear car creeps toward a stationary lead car"
    },
    {
      "time_s": 0,
      "label": "Low-speed bumper contact occurs without mesh penetration; traffic officer holds ego"
    },
    {
      "time_s": 3,
      "label": "Rear car finishes backing away 0.20 m and both incident cars remain stopped"
    },
    {
      "time_s": 6,
      "label": "Investigator reaches the north side of the bumper contact location"
    },
    {
      "time_s": 9,
      "label": "Peak evidence photograph is completed while the upstream hold remains active"
    },
    {
      "time_s": 12,
      "label": "Traffic officer directs only the adjacent following car through the northern channel"
    },
    {
      "time_s": 25,
      "label": "Investigator photographs the lead car from its south side"
    },
    {
      "time_s": 30,
      "label": "Investigator reaches the front of the incident vehicles for a final survey view"
    },
    {
      "time_s": 40,
      "label": "Investigation continues; incident vehicles and warning cone still block ego"
    }
  ],
  "actors": [
    {
      "id": "c029_rear",
      "label": "Rear incident car",
      "kind": "car",
      "role": "Compact sedan that creeps into low-speed bumper contact and then backs away slightly",
      "color": "blue",
      "length_m": 4.4,
      "width_m": 1.8,
      "height_m": 1.5,
      "keys": [
        {
          "t": -7,
          "x": 28,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": -3,
          "x": 31.4,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": -1,
          "x": 32.3,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 0,
          "x": 32.6,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 1,
          "x": 32.5,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 3,
          "x": 32.4,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 32.4,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "At time 0 its front bumper reaches x=34.8, exactly the lead car's rear bumper. The final approach is approximately 0.3 m/s. Motion from 0 to 3 seconds is explicitly reversing with unchanged heading, creating a 0.20 m bumper gap."
    },
    {
      "id": "c029_lead",
      "label": "Stationary lead incident car",
      "kind": "car",
      "role": "Compact sedan receiving the gentle bumper contact and remaining available for inspection",
      "color": "silver",
      "length_m": 4.4,
      "width_m": 1.8,
      "height_m": 1.5,
      "keys": [
        {
          "t": -7,
          "x": 37,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 37,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Rear bumper remains at x=34.8. Contact is a non-graphic low-speed traffic incident; no injury, debris burst, or large deformation is proposed."
    },
    {
      "id": "c029_police",
      "label": "Parked traffic-police response car",
      "kind": "police_car",
      "role": "Stationary response vehicle near the northern road edge",
      "color": "white",
      "length_m": 4.9,
      "width_m": 1.95,
      "height_m": 1.6,
      "keys": [
        {
          "t": -7,
          "x": 45,
          "y": 7.7,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 45,
          "y": 7.7,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Remains parked throughout and leaves a separate channel to its south for the directed following car."
    },
    {
      "id": "c029_follow",
      "label": "Following car directed around the incident",
      "kind": "car",
      "role": "Fourth vehicle, held upstream in the northern channel before receiving a targeted direction to proceed",
      "color": "teal",
      "length_m": 4.3,
      "width_m": 1.8,
      "height_m": 1.5,
      "keys": [
        {
          "t": -7,
          "x": 18.5,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": -3,
          "x": 22,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 0,
          "x": 23,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 12,
          "x": 23,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 18,
          "x": 36,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 25,
          "x": 55,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 32,
          "x": 74,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 94,
          "y": 5,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Stops before the officer, proceeds only after time 12, and passes north of the investigator and south of the parked police car. It remains a persistent actor at its downstream final position."
    },
    {
      "id": "c029_survey",
      "label": "Traffic officer surveying and photographing the accident",
      "kind": "human",
      "role": "Adult investigator inspecting the north side, rear, south side, and front of the incident vehicles",
      "color": "navy",
      "length_m": 0.54,
      "width_m": 0.52,
      "height_m": 1.77,
      "keys": [
        {
          "t": -7,
          "x": 40.8,
          "y": 2.2,
          "z": 0,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 0,
          "x": 40.8,
          "y": 2.2,
          "z": 0,
          "heading_deg": 270,
          "pose": "walk"
        },
        {
          "t": 6,
          "x": 34.8,
          "y": 2.2,
          "z": 0,
          "heading_deg": 270,
          "pose": "phone"
        },
        {
          "t": 9,
          "x": 34.8,
          "y": 2.2,
          "z": 0,
          "heading_deg": 270,
          "pose": "walk"
        },
        {
          "t": 14,
          "x": 29.2,
          "y": 2.2,
          "z": 0,
          "heading_deg": 270,
          "pose": "walk"
        },
        {
          "t": 18,
          "x": 29.2,
          "y": -2.2,
          "z": 0,
          "heading_deg": 360,
          "pose": "walk"
        },
        {
          "t": 25,
          "x": 37,
          "y": -2.2,
          "z": 0,
          "heading_deg": 450,
          "pose": "phone"
        },
        {
          "t": 28,
          "x": 40.8,
          "y": -2.2,
          "z": 0,
          "heading_deg": 450,
          "pose": "walk"
        },
        {
          "t": 30,
          "x": 40.8,
          "y": 0,
          "z": 0,
          "heading_deg": 540,
          "pose": "phone"
        },
        {
          "t": 40,
          "x": 40.8,
          "y": 0,
          "z": 0,
          "heading_deg": 540,
          "pose": "phone"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "This is an explicit sideways inspection route: torso and camera face inward toward the cars while feet move tangentially around them. Phone pose represents taking photographs with the separate camera, not an emergency call. Headings are deliberately unwrapped through 540 degrees."
    },
    {
      "id": "c029_direct",
      "label": "Traffic officer holding ego and directing the northern channel",
      "kind": "human",
      "role": "Adult traffic controller upstream of the accident",
      "color": "lime",
      "length_m": 0.55,
      "width_m": 0.53,
      "height_m": 1.8,
      "keys": [
        {
          "t": -7,
          "x": 25.2,
          "y": 6.4,
          "z": 0,
          "heading_deg": 270,
          "pose": "walk"
        },
        {
          "t": -3,
          "x": 25.2,
          "y": 2.2,
          "z": 0,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 0,
          "x": 25.2,
          "y": 2.2,
          "z": 0,
          "heading_deg": 180,
          "pose": "stop_signal"
        },
        {
          "t": 12,
          "x": 25.2,
          "y": 2.2,
          "z": 0,
          "heading_deg": 130,
          "pose": "point"
        },
        {
          "t": 20,
          "x": 25.2,
          "y": 2.2,
          "z": 0,
          "heading_deg": 180,
          "pose": "stop_signal"
        },
        {
          "t": 40,
          "x": 25.2,
          "y": 2.2,
          "z": 0,
          "heading_deg": 180,
          "pose": "stop_signal"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Approaches southward before turning toward upstream traffic. The time-12 pointing gesture addresses only c029_follow in the northern channel; the other hand continues the hold toward ego. There is no release instruction for the obstructed y=0 corridor."
    },
    {
      "id": "c029_camera",
      "label": "Investigator's evidence camera",
      "kind": "equipment",
      "role": "Persistent handheld camera used for the accident photographs",
      "color": "charcoal",
      "length_m": 0.18,
      "width_m": 0.14,
      "height_m": 0.12,
      "keys": [
        {
          "t": -7,
          "x": 40.8,
          "y": 1.78,
          "z": 1.29840812,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 0,
          "x": 40.8,
          "y": 1.78,
          "z": 1.29840812,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 6,
          "x": 34.8,
          "y": 1.78,
          "z": 1.29840812,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 9,
          "x": 34.8,
          "y": 1.78,
          "z": 1.29840812,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 14,
          "x": 29.2,
          "y": 1.78,
          "z": 1.29840812,
          "heading_deg": 270,
          "pose": "stand"
        },
        {
          "t": 18,
          "x": 29.62,
          "y": -2.2,
          "z": 1.3044734,
          "heading_deg": 360,
          "pose": "stand"
        },
        {
          "t": 25,
          "x": 37,
          "y": -1.78,
          "z": 1.30159188,
          "heading_deg": 450,
          "pose": "stand"
        },
        {
          "t": 28,
          "x": 40.8,
          "y": -1.78,
          "z": 1.30159188,
          "heading_deg": 450,
          "pose": "stand"
        },
        {
          "t": 30,
          "x": 40.38,
          "y": 0,
          "z": 1.2955266,
          "heading_deg": 540,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 40.38,
          "y": 0,
          "z": 1.2955266,
          "heading_deg": 540,
          "pose": "stand"
        }
      ],
      "attach_to": "c029_survey",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0.42,
        0,
        1.3
      ],
      "interaction": "Both hands grip the compact camera ahead of the chest. It follows the investigator's inward-facing orientation throughout the inspection and is never replaced or dropped."
    },
    {
      "id": "c029_cone",
      "label": "Upstream incident-warning cone",
      "kind": "cone",
      "role": "Persistent warning cone separating ego from the incident approach",
      "color": "orange",
      "length_m": 0.45,
      "width_m": 0.45,
      "height_m": 0.7,
      "keys": [
        {
          "t": -7,
          "x": 24.5,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        },
        {
          "t": 40,
          "x": 24.5,
          "y": 0,
          "z": 0,
          "heading_deg": 0,
          "pose": "stand"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Already present during slow-traffic management before time -7. Neither incident car nor the northern passing car intersects its footprint."
    }
  ],
  "acceptance_checks": [
    "Retain exactly four critical vehicles, two officers, one camera, and one cone across all 941 inclusive 20 Hz states.",
    "At time 0, verify bumper tangency at x=34.8, low approach speed, and zero gross penetration. After time 3, verify the 0.20 m bumper gap remains.",
    "Check vehicle footprints against the police road polygon throughout, including c029_follow at its downstream positions.",
    "Verify the northern passing car remains clear of the investigator and retains at least 0.8 m lateral footprint clearance from the parked police car.",
    "Verify the investigator visibly surveys multiple sides and takes photographs, using explicit inward-facing sidesteps at walking speeds of 0.6-1.7 m/s outside start and stop transitions.",
    "Verify camera attachment continuity and hand contact at every interpolated orientation, including headings beyond 360 degrees.",
    "Keep ego stopped at x=13 despite the targeted guidance given to the northern passing car; incident cars and the cone still occupy its corridor at time 40.",
    "Require human approval before Image 2.5 edits the original police photo; do not replace its streetscape with a newly generated setting."
  ],
  "assumptions": [
    "Observed reference evidence is Image 2 and the police map, including a built-up street, parked vehicles, and an overhead enclosed walkway. The accident, officers, and their actions are counterfactual proposals.",
    "The unspecified traffic arrangement is made explicit as four modest vehicles: two incident sedans, one parked police car, and one directed following sedan. Ego is additional and separately controlled.",
    "Officers and the warning cone are already nearby during slow-traffic management before the gentle contact; no instantaneous emergency response or actor spawning is implied.",
    "Vehicle occupants remain inside their vehicles and are not separately instantiated critical actors. No injury detail or vehicle evacuation is proposed.",
    "Playback is finite from -7 to 40 seconds at 20 Hz. Use smooth bounded interpolation, enforce stationary holds, and treat nonhuman stand poses as neutral rigid-object poses.",
    "For attachment consistency, interpret the supplied ground plane as g(x,y)=a*x+b*y+c. Camera key z values compensate for slope while preserving its fixed local vertical offset.",
    "Photographed background occupancy is not fully encoded by the road rings; human review must reject any placement conflicting with a real retained background object.",
    "This JSON records a proposal and requested checks, not completed simulation validation or generated imagery."
  ]
}