Vehicle lamps are examined in an effort to determine if a lamp was ON or OFF at the time of a collision. The ON or OFF condition of the lamp can assist in accident reconstruction and determination of fault.

Filament 1

Determination of ON or OFF is generally based on how the impact from the collision affects the configuration or condition of the filament inside the lamp.

Filament 2

A hot filament that was ON at time of impact. The filament has been stretched and bent, but did not break.