Nighttime accidents often involve pedestrians, cyclists, or obstacles in the roadway, which lead to questions as to the visibility available to the driver. Analysis of lighting conditions at the scene, the visibility conditions at the time, and the amount of contrast between the subject and the background, can answer these questions. Night photography and video analysis can provide demonstrative exhibits, which illustrate the extent to which a subject was visible. Line of sight issues can also be resolved through a geometric analysis of the accident site from the driver perspective.

• Ambient light level measurements
• Target contrast and visibility analysis
• Driver perception-response time
• Pedestrian conspicuity