Accident Reconstruction

Traffic Accident Reconstruction

Traffic accident reconstruction is the effort to determine, from whatever resources are available, how an accident happened. A traffic accident reconstructionist must be familiar with the application of a wide range of mathematics and specialized aspects of vehicle technology.

Because of the wide range of knowledge required by the accident reconstructionist, voluntary certification is available through the Accreditation Commission for Traffic Accident Reconstruction. ACTAR certification includes education, work experience, and successful completion of a comprehensive examination.

Accident reconstruction deals with:

• kinetic energy
• conservation of momentum
• time-distance calculations
• physical evidence from road and vehicle
• crash scene photography analysis
• lamp analysis
• skid analysis 
• airborne analysis
• vehicle data and research
• damage assessment
• vehicle damage location, qualification and quantification
• approach, impact and departure angles
• approach speed calculation,
• impact calculations and Delta-V calculation
• post impact speed calculation

Dr. McElroy specializes in motor vehicle technology and accident reconstruction. This typically entails physical inspection of the damaged vehicles, examination of the accident scene, and reconstruction of collision events using engineering calculations based primarily on momentum, energy, and restitution equations.

Vehicles may include passenger cars, light trucks, commercial vehicles, bicycles, and motorcycles. Information on pre-crash, crash, and post-crash (the 3 phases of a crash) is compiled to best determine how the event (accident, collision, failure) happened. Issues investigated include:

• Vehicle Speeds
• Impact Severity
• Driver Actions
• Seat Belt Use
• Accident Causal Factors
• Collision Avoidance
• Line of Sight / Visibility Problems
• Mechanical Defects
• Tire Failure
• Black Box Data
• Lamp Analysis

Collision Diagram

Motorcycle going wrong way on divided suburban street.

Vehicle Technical Expert & Forensic Mechanic

Box Truck Brake Failure

ASE Certified Master Technician and Expert Witness — Forensic Mechanic and Forensic Mechanical services:

• mechanical and technical inspections
• highway, off-road, and industrial vehicles
• vehicle failure analysis and product liability
• engines, transmission and drive train
• electrical and electronic components
• unintended acceleration or pedal misapplication
• steering gear and linkage
• suspension systems and failure analysis
• brake system operation and failure analysis
• air brakes, hydraulic brakes, & air-hydraulic
• vehicle maintenance
• fleet management

Manufacturing Defect results in Battery Explosion

Dr. McElroy has qualified in Federal and State Courts for criminal and civil trials.

• Insurance, Trucking and Vehicle Rental Industries
• Individual Plaintiff and Defense Counsel
• Industrial and Commercial Corporations
• Local and National Municipalities
• Other Governmental Entities

Dr. McElroy’s ASE Insignia Patch:

• Master Automobile Technician
• Master Heavy Truck Technician
• Master Body & Paint Technician