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There has been a general consensus in the scientific literature that a rim gouging, not scraping, into a roadway surface generates very high forces which can cause a vehicle to overturn in some situations. However, a paper published in 2004 attempts to minimize the forces created during wheel rim gouging and the effect on vehicle rollover. This paper relied largely on heavily filtered lateral acceleration data and discounted additional test runs by the authors and NHTSA that did not support the supposed conclusions. This paper will discuss the effect of rim gouging using accepted scientific methods, including full vehicle testing where vehicle accelerations were measured during actual rim gouging events and static testing of side forces exerted by wheels mounted on a moving test fixture. The data analyzed in this paper clearly shows that forces created by rim gouges on pavement can be thousands of Newtons and can contribute to vehicle rollover.

Recreational Off Road Vehicles (ROVs) which are sometimes referred to as side-by-sides, have increased in popularity over the last decade. These vehicles are available in many different sizes and performance characteristics from a host of different manufacturers and also have a variety of different missions, just as there are many types of off road terrain. The United States Federal Government, through the Consumer Product Safety Commission (CPSC), has advocated and proposed vehicle handling and rollover resistance standards for the side-by-sides which have a top speed above 25 miles per hour (these are not defined as “low speed vehicles”). For the sake of repeatability, the proposed maneuvers are to be performed on a high friction hard surface (like asphalt) as opposed to the off road surfaces (i.e. grass, sand, dirt, mud. rocks, etc.) that these vehicles are designed to be operated on.

The concept of vehicle understeer and oversteer has been well studied and equations, test methods, and test results have been published for many decades. This concept has a specific definition in the steady-state driving range as opposed to quantification in highly transient limit handling events. There have been specific test procedures developed and employed by automotive engineers for decades on how to quantify understeer. These include the constant radius method, the constant steering wheel angle/variable speed method, the constant speed/ variable radius method, and the constant speed/variable steer method. These methods are very good for calculating the understeer gradient but care must be taken in interpreting the result at the limits of tire traction since lateral tire forces can be reduced on a drive axle when significant throttle is applied.

In the field of accident reconstruction, a reconstructionist will often inspect a crash scene months or years after a crash has occurred. With this passage of time important evidence is sometimes no longer present at the scene (i.e. the vehicles involved in the crash, debris on the roadway, tire marks, gouges, paint marks, etc.). When a scene has not been totally documented with a survey by MAIT or the investigating officers, the reconstructionist may need to rely on police, fire department, security camera, or witness photographs. These photos can be used to locate missing evidence by employing traditional photogrammetric techniques. However, traditional techniques require planar surfaces, matched discrete points, or camera matching at the scene.

There have been several recent articles published concerning the effect of a tire tread separation on vehicle handling, but lately the literature has been silent on the situation where a tire airs out. This paper studies how various vehicles steer and handle during and after a tire deflates while the vehicle is traveling at speed. Utility vehicles, pickup trucks, and vans were tested by deflating front and rear tires. The air out condition was created by using a special test device that fired a twelve gauge shotgun shell at the sidewall of a tire while the vehicle was traveling at freeway speeds. The vehicles were instrumented with on board video equipment and a computer with transducers to measure both driver inputs and vehicle responses during the testing. The results show that a rapid tire air out creates a slight pull to the side of the deflated tire which then requires a small corrective steer to maintain a straight ahead course.

In the field of accident reconstruction, it is often important to measure the deformation of a vehicle (i.e. automobile, truck, motorcycle, etc.) after a crash has occurred. This data can be used for many purposes including energy calculations for speed loss, measuring roof or other structural deformation, analyzing seat or seat belt component positions, frame or unitized body structure deformation, and for estimating the actual post crash condition of a vehicle prior to the damage inflicted by the cutting and spreading tools used by emergency personnel. Traditionally, vehicle damage was measured using plumb bobs and tape measures or laser transits. However, these methods are not only time consuming but they also require a significant amount of upfront analysis to determine which points on the vehicle to measure at the inspection. In recent years, newer methods such as photogrammetry software and three dimensional scanners have come into play.

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.