FIRST, AN INTRODUCTORY OVERVIEW OF THE INVESTIGATORY PROCESS IS PRESENTED, WITH ATTENTION TO INFORMATION COLLECTION AND EVALUATION AND FIVE LEVELS OF ACCIDENT INVESTIGATION, INCLUDING REPORTING, AT-SCENE INVESTIGATION, TECHNICAL PREPARATION, PROFESSIONAL RECONSTRUCTION, AND CAUSE ANALYSIS. NEXT, THE BASIS FOR TRAFFIC ACCIDENT INVESTIGATION IS EXAMINED; VARIOUS LAWS AND CODES, NATIONAL STANDARDS FOR ACCIDENT CLASSIFICATION, THE ROLE OF THE FEDERAL GOVERNMENT, AND ASSORTED ADMINISTRATIVE CONSIDERATIONS ARE DISCUSSED. THEN, PREPARATION FOR TRAFFIC ACCIDENT INVESTIGATION IS CONSIDERED; ORGANIZATIONAL PREPARATION, TYPICAL ACCIDENT REPORTING FORMS, INVESTIGATOR TRAINING AND PREPARATION, AND THE PLANNING OF AT-SCENE INVESTIGATIONS ARE DISCUSSED. NEXT, THE COLLECTION OF INFORMATION FROM AND ABOUT PEOPLE IS DETAILED; WITNESS AVAILABILITY, IDENTIFICATIONS, DESCRIPTIONS, THE SUBSTANCE OF WITNESS OR VITCIM INTERVIEWS, INJURIES, THE PREACCIDENT CONDITION OF DRIVERS OR PEDESTRIANS, AND THE DRIVING PROCESS -- DRIVING STRATEGY AND TACTICS, REACTIONS -- ARE DISCUSSED. GATHERING INFORMATION CONCERNING ROADS (IDENTIFYING THE ACCIDENT LOCATION, DESCRIPTIONS OF THE ROAD AND THE EXISTING CONDITIONS, AND OF THE RESULTS OF THE ACCIDENT ON THE ROAD CONDITION) ARE EXAMINED. THE GATHERING OF VEHICLE RELATED DATA IS CONSIDERED; E.G., VEHICLE IDENTIFICATION, DESCRIPTIONS FOR CLASSIFICATION PURPOSES, DAMAGE CLASSIFICATION, THE AT-SCENE DATA NECESSARY TO THE INVESTIGATION OF BOTH MINOR AND SEVERE ACCIDENTS, AND THE TECHNICAL EXAMINATION OF VEHICLES. THE ROLE OF MAPS AND MEASUREMENTS IS DETAILED; MEASUREMENTS LOCATING ACCIDENT RESULTS, MEASURING METHODS, MEASUREMENTS FOR MAPS, MAP PREPARATION, AND THE ACCURACY OF MEASUREMENTS AND MAPS ARE DISCUSSED. THE USE OF PHOTOGRAPHY AS AN INVESTIGATORY TOOL IS EXAMINED, INCLUDING WHEN TO MAKE PHOTOGRAPHS, WHAT TO PHOTOGRAPH, PHOTOGRAPHIC TECHNIQUES AND EQUIPMENT, NEGATIVE IDENTIFICATION, AND ABUSES OF PHOTOGRAPHS ARE DISCUSSED. THE PROCESS OF ACCIDENT RECONSTRUCTION IS DETAILED; THE OBJECTIVES, GENERAL PROCEDURES, AND FUNDAMENTALS, AND THE PRINCIPLES OF VARIOUS ACCIDENT CHARACTERISTICS ARE ENUMERATED. THE ROLE PLAYED IN THE OVERALL ENFORCEMENT PICTURE BY ACCIDENT INVESTIGATION IS ALSO DISCUSSED; THE INVESTIGATION OF SPECIFIC OFFENSES (DRUNK DRIVING, HOMICIDE BY VEHICLE, ETC.), CASE PREPARATION, AND THE COMMON CONCERNS LINKING INVESTIGATION AND ENFORCEMENT ARE EXAMINED. ACCIDENT CAUSES AND FACTORS, THE NATURE OF CAUSES, OPERATIONAL FACTORS, CONDITION FACTORS, CONVENTIONAL CONCEPTS (SPEED, CARELESSNESS) AND CAUSE ANALYSIS ARE CONSIDERED. ACTIVITIES ASSOCIATED WITH ACCIDENT INVESTIGATIONS ARE ALSO OUTLINED, INCLUDING EMERGENCY SERVICES, HIT-AND-RUN, LIABILITY CONSIDERATIONS, INFORMATION FUNCTIONS, AND TESTIMONY. REFERENCES ARE PROVIDED AT THE CLOSE OF EACH CHAPTER. A GLOSSARY AND INDEX ARE INCLUDED, AND PHOTOGRAPHS AND DIAGRAMS ARE USED EXTENSIVELY. (KBL)