NCJ Number
98667
Date Published
1983
Length
330 pages
Annotation
This manual, intended for use in training a select group of police officers in vehicular accident reconstruction, consolidates scientific techniques and applies them to accident reconstruction.
Abstract
Instruction in some simple techniques for dividing lines and arcs and for drawing parallel lines is provided to help the trainee develop the skills required for vector diagramming and the construction of scale diagrams, which are necessary in accident reconstruction. Mathematical formulas are presented for the computation of minimum speed from skidmarks, namely the minimum speed formula, the drag factor formula, and distance formula, all of which are derived from the formula for kinetic energy. Other mathematical formulas provided compute (1) the speed of a vehicle when it left the road to fall to a lower plane, (2) a vehicle's airborne speed, (3) a vehicle speed when the driver lost control on a curve, (4) the kinetic energy of a skidding vehicle, and (5) the radius of a curve transgressed by a vehicle. Instruction is also provided in the use of quadratic equations and time-distance equations. One chapter teaches grid photography or photogrammetry, which involves techniques for using the camera and constructing a grid on a photograph of an object of known size. Other chapters discuss the law of conservation of momentum and how it can determine the speeds of vehicles at impact as well as the calculation of speed from skidmarks of a vehicle that has faulty brakes. Appendixes contain instruction in refresher mathematics and mathematical problems to be solved by the trainee.