关键词: 肇事车辆速度；光源类型；车辆特征点；路面影子；车速误差分析；数据准确性

Abstract: In the field of vehicle speed identification in road traffic accidents, the shadow speed measurement method is an unconventional approach that calculates vehicle speed based on the moving distance of the shadow formed by vehicle characteristic points on the road surface and the corresponding time. The accuracy of this method is affected by factors such as the type and position of the light source, as well as environmental conditions. This paper studies the shadow speed measurement method, analyzes the impact of using shadows formed by natural and artificial light sources on the accuracy of speed calculations, and discusses the corresponding causes of errors. Through theoretical analysis and practical verification, specific strategies for reducing errors are creatively proposed, along with three novel and unique practical methods aimed at minimizing speed calculation errors and improving the accuracy of results.

Key words: speed of the vehicle involved in the accident; light source type; vehicle feature points;road shadow; vehicle speed error analysis; data accuracy