Library

This is a linked index to all articles and tools on our web site. 

Automotive Event Data Recorders

     On-board crash data event recorders (black boxes) are now installed on many new cars and light trucks.  These devices record a vehicle's speed, seat belt use, brake application and more for up to 5 seconds before an impact.

Skid Speed Calculator

     This is an on-line calculator that will provide the minimum speed of a car through a skid. It is not a substitute for a thorough collision analysis by a qualified accident reconstructionist.

Skidmarks

     These are two articles on determining speeds from skid marks and evaluating skid mark evidence.

Photogrammetry

Photogrammetry is used in many different fields including topographic mapping, engineering,
archeology and police traffic crash and crime scene investigations.

Night-time Photography

     A short article on some of the technical difficulties of trying to obtain a photographic image of what a driver could have or should have seen just before an accident during the hours of darkness or periods of twilight.

Lamp Examination to Determine On or Off in a Collision

     There are ways to tell if the headlights, taillights or brake lights on a car were on or off following a collision. This article details some of the things to look for when conducting a lamp examination.

Environmental Factors - Determining Ambient Light Levels

     A large percentage of accidents happen just at sunset and sunrise. Do you know how to tell when civil twilight begins and ends? Many states require headlights to be used in conjunction with civil twilight. The possibility of glare from the sun can also be analyzed. This article provides details and resources on determining the position of the sun and moon for any place on Earth at any time and where to obtain historical weather data. Updated in 2005.