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A follow-up case study on rollover testing with a single full-size sport utility vehicle (SUV) was conducted under controlled real-world conditions. The purpose of this study was to conduct a well-documented rollover event that could be utilized in evaluating various methods and techniques over the phases associated with rollover accidents. The phases documented and discussed, inherent to rollovers, are: pre-trip, trip, and rolling phases. With recent advances in technology, new devices and techniques have been designed which improve the ability to capture and document the unpredictable dynamic events surrounding vehicle rollovers. One such device is an inertial measurement unit (IMU), which utilizes GPS technology along with integrated sensors to report and record measured dynamic parameters real-time. The data obtained from a RT-4003 IMU device are presented and compared along with previous test data and methodology.

Test methods for vehicle safety development are either based on the movement of a vehicle into a stationary barrier or the movement of a barrier into a stationary vehicle. When deemed necessary, a two-moving-vehicle impact is approximated by modifying the impact motion between the moving and stationary objects. For example, the Federal Motor Vehicle Safety Standard (FMVSS) 214 side-impact crash test procedure [1] approximates the lateral impact of a moving vehicle into the side of another moving vehicle by using a moving barrier with wheels crabbed so that the velocity vector of the barrier is not collinear with its longitudinal axis. Such approximations are valid when the post-impact motions of the two vehicles are not to be evaluated. Similarly, the published data indicates that historic analyses of motorcycle accidents and the advancements in motorcycle safety designs have been based, in large part, on single-moving-vehicle crash tests.

There has been little published research into simulating two-moving motorcycle-to-car collisions for the purpose of accident reconstruction. In this paper a series of two-moving crash tests were conducted to study collisions of this type. These tests used a range of speeds for the cars and the motorcycles involved, with perpendicular and oblique intersection collision impact configurations. The tests were then simulated with two popular crash simulation packages which were not designed to simulate motorcycles. The purpose of this study was to evaluate existing techniques and develop new techniques for simulating motorcycles in these software packages and then to examine the ability of each package to simulate a two-moving motorcycle-to-car crash. The results demonstrate that it is indeed possible to simulate a motorcycle in these packages and that both packages can simulate two-moving motorcycle-to-car crashes reasonably well.

Much has been written about reconstruction techniques and testing methods concerning vehicle rollovers. To date, most of the literature describes rollovers as one-dimensional events. Rollovers account for a disproportionate fraction of serious injuries and fatalities among all motor vehicle accidents. The three-dimensional nature of rollover sequences in which a rolling vehicle experiences multiple ground contacts contributes to the environment where such injuries occur. An analytical technique is developed to model the airborne segments of a rollover sequence as a parabolic path of the vehicle center of gravity. A formulation for the center of gravity descent from maximum elevation to full ground contact is developed. This formulation contains variables that may be readily determined from a thorough reconstruction. Ultimately, this formulation will also provide a vertical ground impact velocity at contact.

Most rollover literature is statistical in nature, focuses on reconstructed field data and experiences, or utilizes a very broad pool of dissimilar test data. When test data is presented, nearly all of it involves hard surface rollover tests performed at speeds near 30 mph, with a mix of passenger cars, sport utility vehicles and minivans. Five full-scale dolly rollover tests on dirt of production sport utility vehicles (SUV) and multi-purpose vehicles (MPV) were performed with similar input parameters. The similarities included Federal Motor Vehicle Safety Standard (FMVSS) 208 rollover dolly initiated events, level dirt rollover surfaces, and initiation speeds over 40 mph. All tests were recorded with multiple high-speed and real-time cameras. Additionally, some of the tests included detailed documentation of the rollover surface and the resulting evidence and debris patterns, as well as onboard angular rate sensing instrumentation.

Research focusing on automotive rollovers has garnered a great deal of attention in recent years. Substantial effort has been directed toward the evaluation of rollover resistance. Issues related to crashworthiness, such as roof strength and restraint performance, have also received a great deal of attention. Much less research effort has been directed toward a more detailed study of the rollover dynamics from point-of-trip to point-of-rest. The reconstruction of rollover crashes often requires a thorough examination of the events taking place between point-of-trip and point-of-rest. Increasing demands are placed on reconstructionists to provide greater levels of detail regarding the roll sequence. Examples include, but are not limited to, roll rates at the quarter-roll level, CG trajectory (horizontal and vertical), roll angle at impact, and ground contact velocity. Often the detail that can be provided in a rollover reconstruction is limited by a lack of physical evidence.

Three rollcaged and three production roof vehicles were exposed to matched-pair rollover impacts using the Controlled Rollover Impact System (CRIS). The roof-to-ground contacts were representative of severe impacts in previous rollover testing and real world rollovers. The seat belted dummies measured nearly identical head impacts and neck loads with or without the rollcage, despite significant roof crush in the production roof vehicles. Roof crush had no measurable influence on the severity of the head accelerations and neck loads.

To date, the most commonly used rollover test device has been the rollover dolly described in the SAE J2114 recommended practice, which is commonly referred to as the “208 rollover dolly.” However, for a number of reasons, the rollover dolly has never been accepted as a standard for rollover testing. One of the primary limitations of the rollover dolly has been the controllability of the first roof-to-ground impact. A new rollover test device, known as the Controlled Rollover Impact System (CRIS), was presented at the SAE Congress in March 2001. This device allows the roll, pitch, and yaw angles, roll rate, translational velocity, and drop height of the vehicle to be specified for the first roof-to-ground impact. One objective of the current study was to compare the vehicle dynamics produced by each test device using an Econoline-350 van as the test vehicle.