NCJ Number
197117
Date Published
2001
Length
66 pages
Annotation
This chapter discusses the importance of and the methods for collection of information concerning the use of lights by a vehicle involved in a motor vehicle accident.
Abstract
This circumstances warranting lamp examination are covered in this chapter. The causes of opposite direction collisions at night, angle collisions, single vehicle collisions, hit-and-run accidents, fleeing pursuit, as well as same-direction collisions, may be explained by lamp examination of the vehicles involved in the accident. The normal lamp is discussed, with lamp descriptions given, photos and diagrams illustrating the descriptions, and general principles of operation described. Also, aged lamps, lamp failure, heavy duty lamps, third filament lamps, and indexing of double filament lamps are discussed. Halogen lamps and their principle of operation, including sealed beam and non-sealed beam lamps, and varied types of replacement bulbs, are discussed. High intensity discharge lamps are noted, and lamp markings which describe how they are to be used are discussed. At-scene observations, record-keeping, and circumstances are covered. Lamp abnormalities resulting from collisions and the principles involved for deciding whether a lamp was on or off are discussed, including filament oxidation, oxide coating of filament, time of oxidation, fused glass particles, and filament deformation. Other topics covered include indefinite indications, peculiar circumstances, examining lamps and testing circuits, handling and storing lamps, lamps commonly used on motor vehicles, and a summary of the history of lighting used in motor vehicles. A list of reference sources is included at the end of the chapter.