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The original Malibu II study, conducted by Bahling et al, found that neck compression loading in rollover crashes is caused by the occupant moving toward the ground and therefore, roof crush was not causally related to the loading. Some have disputed this finding claiming that the occupant does not “dive toward the roof,” but rather, the roof “moves in” toward the occupant, and that roof deformation is the primary cause of cervical spine injuries in rollover crashes. The original study included a detailed analysis of film and force transducer data for 10 Potentially Injurious Impacts (PII's). This paper presents an independent analysis of these 10 PII's and one additional PII. This analysis uses the film and transducer data to evaluate the timing of roof deformation and neck loading, the magnitude of roof deformation at the time of peak neck load, and the motion of the vehicle and occupants in the inertial reference system.

A test method was developed whereby repeated pole impacts could be performed at multiple locations per test vehicle, allowing a comparison of energy and crush relationships. Testing was performed on vehicles moving laterally into a 12.75 inch diameter rigid pole barrier. Crush energy absorption characteristics at the different locations were analyzed, and the results compared to test data from broad moving barrier crashes and available crash tests with similar pole impacts. Crush stiffness characteristics for narrow impacts at various points on the side of the Taurus vehicle platform were documented. Factors encountered during the research include the importance of rotational energy accounting and uncertainties related to crush energy related to induced deformation. The findings show that the front axle and A-pillar regions are much stiffer than the CG and B-pillar areas to narrow rigid pole impact.

While vehicular rear pole impacts are rare, they do occur, and can be very serious. General accident reconstruction methods, which derive vehicle stiffness values from rear barrier crash tests, over-predict the impact speed for these types of pole impacts. Thirteen pole crash tests were run into the rear-ends of four 4-door, front-wheel drive sedans. Repeated crash testing was used on three of the vehicles. Two 1988 Acura Legends, which have one of the highest stiffness values from FMVSS 301 Rear Compliance crash testing, a 1988 Honda Civic, which has one of the softest rear-end stiffnesses, and a 1986 Ford Taurus were tested. The repeated crash testing methodology was validated using one of the 1988 Acura Legends and a previously published Ford Taurus test. Residual crush was measured using maximum crush, point-to-point, longitudinal full-width, and longitudinal reduced-width methodologies. Crush was found to be linearly related to impact speed.

Understanding occupant kinematics is an important part of accident reconstruction, particularly with respect to injury causation. Injuries are generally sustained as the occupant interacts with the vehicle interior surfaces and is rapidly accelerated to the struck component's post-impact velocity. This paper describes some methods for assessing occupant kinematics in a collision, and discusses their limitations. A useful technique is presented which is based on free-body analysis and can be used to establish an occupant's path of motion relative to the vehicle, locate the point of occupant contact, and determine the occupant's velocity relative to that contact location.

Markings or observable anomalies on seat belt webbing and hardware can be classified into two categories: (1) marks caused by collision forces, or “loading marks”; and (2) marks that are created by non-accident situations, or “noncollision marks”. In a previous work, a survey of the driver's seat belt of 307 vehicles that had never experienced a collision was conducted, and several examples of marks created by normal, everyday usage, or “normal usage marks” were presented. It was found that some normal usage marks were visually similar to loading marks. This paper presents several examples comparing loading marks to visually similar normal usage marks and discusses the important similarities and differences.

The assessment of seat belt usage during a collision is typically made by considering four types of evidence: (1) the nature and location of the occupant’s injuries, (2) the presence or absence of occupant contact marks in the passenger compartment, (3) the occupant’s final position and (4) markings on the restraint system. This paper focuses specifically on seat belt restraint system markings. Markings or observable anomalies on the webbing and restraint system hardware can be classified into two categories: (1) those caused by collision forces, or “loading marks” and (2) those created by noncollision situations, or “normal usage marks”. Some normal usage marks can appear visually similar to loading marks. The purpose of this paper is to help the investigator distinguish between occupant loading marks and normal usage marks by presenting examples of marks found on belt restraint systems that have never experienced occupant loading in a collision.

Occupant simulation models have been used to study trends or specific design changes in “typical” accident modes such as frontal, side, rear, and rollover. This paper explores the usage of the Articulated Total Body Program (ATB) as an accident reconstruction tool. The importance of model validation is discussed. Specific areas of concern such as the contact model, force-deflection data, occupant parameters, restraint system models, head/neck loadings, padding, and intrusion are discussed in the context of accident reconstruction.

Rollover accidents are responsible for a significant percentage of crash injuries. Increasing seat belt restraint use is the most effective way to reduce rollover injuries. Injuries to restrained occupants are also of interest. It has been suggested that head/neck injuries are caused by roof crush, and that modification to roof structures and seat belt systems would lead to a substantial reduction in severe rollover injuries. Field accident data and rollover testing are used to evaluate the relationship between roof crush, seat belt design, and severe rollover injuries.