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In this study, tests were performed with modified tires at the various front and rear positions on seventeen different vehicles to determine the effect of a full tire tread belt separation on a vehicle at highway speeds. The driver's steering and braking inputs were measured along with the vehicle responses during the event. The results show that the forces of a full tread belt separation generally do not force a vehicle out of a driver's control and that only small steering corrections are required to remain in the original lane of travel during the tread belt separation event. Additionally, forces due to the separating tires do not result in violent hop or tramp suspension responses during the separation event.

There has been very little investigation into the area of tire aging and whether storing a tire will change it's properties, in particular ‘limit’ or ‘saturated’ properties, over time. In order to study how the performance characteristics of tires change when the tires are stored, a series of force and moment tests were performed on five modern day radial tires of different make, brand, type, and size. The tires were all purchased at the same time for a given tire set and had the same DOT code. Near the date of purchase, some of the tires were tested on the Veridian TIRF (Tire Research Facility) machine in order to measure their force and moment characteristics. Other tires of the lot were placed on a tire rack in a storage building. Years later, these tires were sent to the same test facility and were measured under the same test conditions. The data indicates that tire performance characteristics change very little with time.

In this study, tests were performed on four different vehicles, each equipped with a version of electronic stability control (“ESC”). Tests were performed on a 2000 four door sedan, a 2002 four door sedan, a 2002 five door hatchback, and a 2003 large rear wheel drive sport utility vehicle. This selection allowed for the evaluation of different ESC systems and strategies on their ability to accommodate a separated rear tire. The steer inputs were applied to the vehicles manually by test drivers and were purposely selected to generate displacements so that the ESC systems would activate. The results of this study demonstrate that ESC systems can be overwhelmed by some steering demands when a rear tire has lost its tread. This fact does not constitute a problem with the ESC systems or the vehicles tested. It merely confirms that ESC systems will not always keep a vehicle from sliding or spinning out when a tire is disabled.

In this study, tests were performed on eight different vehicles, each equipped with a version of electronic stability control (“ESC”). Tests performed on a dry test surface included a 1999 two door sports car, a 2000 four door sedan, a 2002 four door sedan, a 2003 large rear wheel drive sport utility vehicle, and a 2002 five door hatchback. Tests performed on a wet surface were isolated to a full size rear wheel drive sport utility vehicle. Tests performed on a snow and ice covered surface included a 2003 mid size sport utility vehicle, a 2002 full size sport utility truck, and a 2007 mid size sport utility vehicle; all from different manufacturers. This selection allowed for the evaluation of different ESC systems and strategies on various surfaces to violent steering demands. The steer inputs were applied to the vehicles manually by test drivers and were purposely selected to generate large displacements so that the ESC systems would activate.

In this study, tests were performed with modified tires at the right rear location on a solid rear axle sport utility vehicle to compare the vehicle inputs from both: (1) tire tread belt detachments staged by circumferentially cut tires, and (2) a tire tread detachment staged by distressing a tire in a laboratory environment. The forces and moments that transfer through the road wheel were measured at the right and left rear wheel locations using wheel force transducers; displacements were measured between the rear axle and the frame at the shock absorber mounting locations, ride height displacements were measured at the four corners of the vehicle, and accelerations were measured on the rear axle. Onboard vehicle accelerations and velocities were measured as well. The data shows that the tire tread belt detachments prepared by circumferentially cut tires and distressed tires have similar inputs to the vehicle.

In this study, tests were performed to understand the effects of asymmetric longitudinal forces on vehicle response which may be created in certain staged partial tire tread belt detachment tests. In a very small number of tests performed by others, tires cut to simulate partial tire tread belt detachments created longitudinal drag forces at the separating tire that induced substantial vehicle yaw. This drag force and yaw response are independent of vehicle type and suspension type; they are created by the separating tire tread interacting with the road surface and / or vehicle. Similar yaw inducing drag forces are further demonstrated by applying braking to only the right rear wheel location of an instrumented test vehicle. It is shown that vehicle yaw response results from this longitudinal force as opposed to vertical axle motion.

In this study, tests were performed with modified tires at the right rear location on a solid axle sport utility vehicle to compare vehicle inputs and responses from both: (1) staged tire tread belt detachments, and (2) stepped diameter (“lumpy”) tires. Lumpy tires consist of equal size sections of tread that are vulcanized at equidistant locations around the outer circumference of the tire casing. Some have used lumpy tires in attempt to model the force and displacement inputs created by a tire tread belt separation. Four configurations were evaluated for the lumpy tires: 1-Lump, 2-Lump (2 lengths), and 3-Lump.

The severity of an impact in terms of the acceleration in the occupant compartment is dependent not only on the change in vehicle velocity, but also the time for the change in velocity to occur. These depend on the geometry and stiffness of both the striking vehicle and struck object. In narrow-object frontal impacts, impact location can affect the shape and duration of the acceleration pulse that reaches the occupant compartment. In this paper, the frontal impact response of a full-sized pickup to 10 mile per hour and 20 mile per hour pole impacts at the centerline and at a location nearer the frame rails is compared using the acceleration pulse shape, the average acceleration in the occupant compartment, and the residual crush. A bilinear curve relating impact speed to residual crush is developed.