{
  "name": "BR-001-test",
  "description": "테스트 직선 선형 — 40 m 경간 거더교",
  "coordinate_system": "local",
  "stations": [
    {"station":  0.0, "x":     0.0, "y": 0.0, "z":     0.0},
    {"station":  5.0, "x":  5000.0, "y": 0.0, "z":     0.0},
    {"station": 10.0, "x": 10000.0, "y": 0.0, "z":     0.0},
    {"station": 20.0, "x": 20000.0, "y": 0.0, "z":     0.0},
    {"station": 30.0, "x": 30000.0, "y": 0.0, "z":     0.0},
    {"station": 40.0, "x": 40000.0, "y": 0.0, "z":     0.0}
  ],
  "specs": {
    "type": "highway",
    "design_speed": 80,
    "lanes": 2,
    "lane_width_mm": 3750
  }
}