Measuring accident scenes using laser scanning systems and the use of scan data in 3D simulation and animation

Abstract

Paper presented at the 23rd Annual Southern African Transport Conference 12 - 15 July 2004 "Getting recognition for the importance of transport", CSIR International Convention Centre, Pretoria, South Africa. The Investigations and Risk Management Group of TRL Limited has been researching and developing applications for 3D laser scanning technology in traffic accident investigation and reconstruction. Laser scanning systems can rapidly capture vast amounts of data thereby allowing such systems to ‘preserve’ incident scenes. This data also provides a source for the construction of detailed three dimensional models which can be used in vehicle dynamics simulation and incident animation. Applications of this technology in accident investigation and reconstruction include the spatial measurement of physical evidence at traffic accident scenes, including: vehicle positions, vehicle damage, tyre and other road marks, debris, the road geometry and that of the surrounding environment. Preliminary studies have determined that the use of laser scanning systems could allow significant time savings to be made in the measurement of complex road traffic accident scenes as well as capturing significantly more spatial data at such scenes than is possible using surveying systems such as total station. Laser scan data has been used to generate detailed road surface models, in the form of dense three dimensional meshes. These surfaces can be used for complex vehicle dynamics simulations where the precise geometry of the road surface is important to the simulation. Laser scanning systems also allow detailed geometric data to be captured at sites where such data is difficult or impractical to measure using other means. As the use of laser scanning systems at incident scenes (or sites) typically involves the measurement of areas surrounding the road such as topography, buildings, vegetation etc., this information can be used to construct detailed three dimensional environments to enhance computer simulations, or within which to animate the circumstances of an incident. This paper describes the use of laser scanning systems at incident scenes and presents examples of the use of ‘scan’ data in the development of complex vehicle dynamics simulations and animated incident sequences. Through the work carried out by TRL, laser scanning has been found to provide a valuable tool for accident investigation, analysis, and the presentation of accident reconstruction.