Research Papers (2009 – 2013)

Abstract

In traffic crash reconstruction is important to determine the vehicle speed at the time of collision. For this, we can use the physics laws or alternative methods. In this perspective, an interesting technique to establish this speed is the needle slap effect, in which an imprint made at time of impact by the needle of the speedometer on the face of the gauge. In this work, we show how to identify this effect using various laboratory techniques, such as Raman Spectroscopy, to prove the material transfer between gauge face and needle; Video Spectral Comparator, to find luminescence and friction marks of the needle at the gauge plate; and Optical Microscope, to investigate alteration of morphological characteristic on the gauge back. For this purpose, we analyzed cars and motorcycles dashboards that had been involved in traffic accidents. Finally, we use a set of lights (flashlights) combined with several filters (goggles) to detect this phenomenon, at the accident scene, when it is impossible to remove the instrument panel to be analyzed in the laboratory.

Juliano de Andrade Gomes, Charles Albert Andrade