3.6 Crash Classification by Number of Vehicles
3.6.1 introduction: The purpose of this classification is to describe a motor vehicle crash in terms of the number of motor vehicles in-transport which are involved, or other-road-vehicle crash in terms of the number of other-road-vehicles in-transport which are involved.
3.6.2 categories: The categories for classification of road vehicle crashes by number of vehicles are:
• Single-vehicle crash
• Two-vehicle crash
• Three-vehicle crash
• And so on
3.6.3 noncontact road vehicles: A noncontact (or “phantom”) road vehicle is not counted as one of the road vehicles involved in a crash (See 2.4.8). Noncontact vehicles may or may not be recorded on crash reports but should not be counted when classifying crashes by number of vehicles involved. Information about a noncontact vehicle may be recorded for legal purposes, but such vehicles are not counted for statistical purposes.
3.6.4 single-vehicle crashes: Common types of single-vehicle crashes are noncollision crashes or crashes involving pedestrians, fixed objects, wild animals, or unrestrained domestic animals.
3.6.5 school bus: If a school bus is directly involved (as a contact vehicle) in a motor vehicle crash, the school bus is counted as any other motor vehicle would be. If a school bus is indirectly involved (e.g., as a noncontact vehicle) in a motor vehicle crash or an other-road-vehicle crash, it is not counted.