THIS BOOK DESCRIBES HOW AUTOMOBILES, TRUCKS, AND MOTORCYCLES ARE BUILT, WITH EMPHASIS ON THOSE PARTS WHOSE FAILURE CAN LEAD TO AN UNEXPECTED LOSS OF VEHICLE CONTROL. THE SYMPTOMS OF ACCIDENT-PRODUCING MECHANICAL FAILURES AND THE TYPES OF FAILURES THAT OCCUR MOST FREQUENTLY ARE DESCRIBED AS WELL AS THE BASIC PHYSICS GOVERNING VEHICLES ON THE ROAD. COLLISION ANALYSIS IS DISCUSSED IN TERMS OF CONSERVATION OF ENERGY AND MOMENTUM. WHY AND HOW VEHICLES DEFORM ON IMPACT AND METHODS FOR DETERMINING THE PATHS AND SPEEDS OF VEHICLES BEFORE AN ACCIDENT ARE TWO OF THE PROBLEMS CONSIDERED. THE BOOK EXPLAINS THE FORMULATION AND USE OF MATHEMATICAL EQUATIONS BASED ON THE PHYSICS OF COLLIDING OBJECTS. SKIDMARK ANALYSIS PROVIDES INFORMATION ON THE TIRE FOOTPRINT, FRICTION FORCE, DIRECTIONALITY, HYDROPLANING, BRAKING EFFICIENCY, AND SOURCES OF ERROR. SPEED IS DETERMINED FROM TRUCK, TRAILER, AND MOTORCYCLE SKIDMARKS. DESCRIPTIONS AND ILLUSTRATIONS ARE FURNISHED OF TYPES OF VEHICULAR ACCIDENTS AND FACTORS CAUSING THEM. SPECIAL ATTENTION IS GIVEN TO THE STOPPED CAR INVOLVED IN COLLISIONS; HEAD-ON, REAR-END, AND INTERSECTION COLLISIONS; TRUCK-TRUCK, MOTORCYCLE, AND ROLLOVER ACCIDENTS; PEDESTRIAN ACCIDENTS; AND VEHICLE FIRES. INFORMATION ON ACCIDENT RECONSTRUCTION AIDS INCLUDES THE PROCESS OF INVESTIGATION, MAPPING AND MODELING, LINE OF IMPACT, DETERMINING SPEED CHANGE FROM DAMAGE, AND PHOTOGRAPHY AND RECORD KEEPING AT THE SCENE. GENERAL GUIDELINES ARE OFFERED FOR THE APPLICABILITY OF THE TECHNIQUES SUGGESTED. PHOTOGRAPHS, FIGURES, STATISTICAL DATA, AND AN INDEX ARE INCLUDED. (AUTHOR ABSTRACT MODIFIED--MRK)