{
  "catalog_id": 22,
  "title": "Three teenage shared-bike riders in eastbound pursuit",
  "source_template": "police",
  "summary": "Exactly three teenagers ride shared bicycles east. The leader maintains a straight line and steady pace while both following riders repeatedly increase cadence to close their gaps. They remain in safe single-file pursuit within ego's corridor through 40 seconds, so ego does not resume.",
  "focus_xy": [
    48,
    0.6
  ],
  "initial_review_time_s": 0,
  "ego_stop_x_m": 14,
  "ego_release_s": -1,
  "events": [
    {
      "time_s": -7,
      "label": "Three teenage shared-bike riders approach east in a separated single-file formation."
    },
    {
      "time_s": -3,
      "label": "Both following riders increase cadence to pursue the steady leader."
    },
    {
      "time_s": 0,
      "label": "The two pursuers visibly reduce their initial gaps without overtaking."
    },
    {
      "time_s": 6,
      "label": "The first pursuit effort brings the riders closer while preserving bicycle clearance."
    },
    {
      "time_s": 12,
      "label": "The first pursuer briefly eases cadence; all three continue moving east."
    },
    {
      "time_s": 20,
      "label": "A renewed catch-up effort produces a tighter pursuit formation."
    },
    {
      "time_s": 28,
      "label": "The group continues east in compact, collision-free pursuit."
    },
    {
      "time_s": 40,
      "label": "All three riders remain ahead in ego's corridor; the finite rehearsal ends without ego release."
    }
  ],
  "actors": [
    {
      "id": "c022_lead",
      "label": "Teen 1: straight eastbound shared-bike leader",
      "kind": "cyclist",
      "role": "Integrated teenage rider and shared bicycle; steady leader.",
      "color": "blue",
      "length_m": 1.85,
      "width_m": 0.65,
      "height_m": 1.5,
      "keys": [
        {
          "t": -7,
          "x": 42,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": -3,
          "x": 49.2,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 0,
          "x": 54.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 6,
          "x": 65.4,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 12,
          "x": 76.2,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 20,
          "x": 90.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 28,
          "x": 105,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 34,
          "x": 115.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 40,
          "x": 126.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Rides directly east at 1.8 m/s without lateral weaving, looking forward and keeping both hands on the handlebars. The rider and bicycle form one actor."
    },
    {
      "id": "c022_chase1",
      "label": "Teen 2: first shared-bike pursuer",
      "kind": "cyclist",
      "role": "Integrated teenage rider and shared bicycle; first pursuer.",
      "color": "blue",
      "length_m": 1.85,
      "width_m": 0.65,
      "height_m": 1.5,
      "keys": [
        {
          "t": -7,
          "x": 34,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": -3,
          "x": 41.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 0,
          "x": 47.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 6,
          "x": 59.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 12,
          "x": 70.2,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 20,
          "x": 85.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 28,
          "x": 100.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 34,
          "x": 111.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 40,
          "x": 122.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Makes two gentle cadence increases to pursue the leader, briefly moderating speed between them. Remains behind the leader without contact, passing, or a lane change."
    },
    {
      "id": "c022_chase2",
      "label": "Teen 3: second shared-bike pursuer",
      "kind": "cyclist",
      "role": "Integrated teenage rider and shared bicycle; second pursuer.",
      "color": "blue",
      "length_m": 1.85,
      "width_m": 0.65,
      "height_m": 1.5,
      "keys": [
        {
          "t": -7,
          "x": 26,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": -3,
          "x": 33.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 0,
          "x": 40.4,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 6,
          "x": 52.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 12,
          "x": 64,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 20,
          "x": 80.4,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 28,
          "x": 95.8,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 34,
          "x": 107.2,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        },
        {
          "t": 40,
          "x": 118.6,
          "y": 0.6,
          "z": 0,
          "heading_deg": 0,
          "pose": "handlebar"
        }
      ],
      "attach_to": "",
      "attach_start_s": -7,
      "attach_end_s": 40,
      "attach_offset_xyz": [
        0,
        0,
        0
      ],
      "interaction": "Continually pursues the two riders ahead, using repeated modest cadence increases to reduce the gap. Keeps both hands on the handlebars and retains a safe following distance."
    }
  ],
  "acceptance_checks": [
    "Require exactly three cyclist actors, each including one teenager and one shared bicycle; do not create separate duplicate bicycle or rider actors.",
    "Keep the leader's y coordinate fixed at 0.6 and heading fixed at 0 degrees throughout the complete eastbound route.",
    "Require both following riders to demonstrate sustained pursuit with repeated catch-up efforts, rather than substituting a crossing or unrelated cycling event.",
    "At every playback sample, keep bicycle footprints inside the police road polygon and preserve at least 4 m center-to-center longitudinal separation, approximately 2.15 m clear bicycle gap.",
    "Use smooth forward-only bicycle motion, approximately 1.75 to 2.25 m/s, with no abrupt acceleration, overtaking, contact, or heading reversal.",
    "Keep all three riders present through 40 seconds and ego stopped at x=14; ego_release_s=-1 must remain in force because the riders continue occupying its corridor.",
    "Human review must approve the complete route, source-photo placement, counts, and continuous spacing before image generation; no validation result is asserted here."
  ],
  "assumptions": [
    "Image 2 supplies broad street and building context only. The police template is a map choice, not an instruction to add police; all three riders and their behavior are counterfactual.",
    "The teenagers are represented as small young-teen silhouettes with approximately 1.5 m stature. Each 1.85 m long low-step shared bicycle and its mounted rider are represented by one combined cyclist actor.",
    "All three bicycles use the same modest blue shared-bike design. Persistent rendered role labels distinguish the leader and two pursuers without inventing additional props.",
    "The 47-second route necessarily extends east beyond the initial x=25..50 interaction area, but remains within the supplied road polygon and map extent.",
    "Playback is finite and non-looping from -7 through 40 seconds at 20 Hz, including 941 samples. Use monotone, acceleration-bounded interpolation that preserves the specified ordering and minimum gaps; z=0 follows mapped ground.",
    "Ego approaches along y=0 from x=13 at -7 seconds, brakes from 2 m/s to rest at x=14 by -6 seconds, and remains there through 40 seconds. No artificial clearing maneuver or out-of-frame deletion is proposed.",
    "Exact retained-vehicle footprints require human inspection. A later Image 2.5 edit must use original Image 2 and this rehearsal only for position and posture, after human approval."
  ]
}