[
  {
    "type": "vehicle_group",
    "id": "police_pileup",
    "vehicles": [ [ "bearcub", 40 ] ]
  },
  {
    "type": "vehicle_group",
    "id": "city_pileup",
    "vehicles": [ [ "bearcub", 8 ] ]
  },
  {
    "type": "vehicle_group",
    "id": "military_vehicles",
    "vehicles": [ [ "bearcub", 5 ] ]
  }
]
