交通事故現場相片最能完整記錄現場資訊，但因缺乏像點或物件間之幾何關係，所以處理員警必須針對現場跡證逐一量測以繪製現場圖，此為現場處理較為費時之作業項目，而在實務上，現場圖的錯漏亦為事故處理最常見的缺失項目。因此，本研究利用近景攝影測量(Close-range Photogrammetry)方法以獲得相片資訊，在兼顧警察單位現有設備、現場處理作業與精度需求等條件下，以改良透視網格法(Perspective Grid Method)為基礎，進行事故現場之還原，並利用數值影像，配合使用簡易繪圖工具，量測物體之相片座標，以試算表所開發之計算模組，計算物體之空間相對座標，獲得還原結果。在事故現場攝影與還原作業時，對可能造成誤差項目，如鏡頭種類、攝影角度、高度、地面高程、像點定位等，本文均逐一進行測試分析，依誤差項目特性調整修正測距公式，分析誤差因子對測距的影響程度，以增加測距公式的穩定度並降低測距誤差。最後再以實際的事故現場進行實證測試，均獲致良好之還原結果。由於本法不需要特殊儀器裝備且在執行上亦不需大幅調整現行事故處理程序，若員警在現場量測時，如有疏忽或遺漏，可藉由本法進行校核或補正。

Photos taken at the traffic accident scene preserve the situation of the scene and information of the accident better than any other types of records. However, due to its lacking of the geometric information among objects on the photo, police officers still need to measure the geometric data of every evidence at the scene to make an after-accident situation map. This takes not only more police hours, but also causes more human errors. This study is trying to apply the close-range photogrammety techniques to grab the geometric information on a picture to improve the proficiency and accuracy of reconstructing an accident scene. Based on the perspective grid method, it can be done by simply using an image processing software and digital images of the scene. A sensitivity study of the type of lens of the camera, the height and angle of camera while shooting, the difference of elevation of the surface, and the possible human errors of locating an object on a digital image was conducted and presented in this article.The result shows that an accident scene can be measured by using this modified perspective grid method and achieve the required precision without any extra special equipment or altering any regular procedures to the police work.