In recent years crash investigators have been investigating rollover crashes more frequently. Rollover collisions have been occurring since the invention of the automobile but with the increased popularity of light trucks (SUVs, pickups, mini-vans) there has been an increase in the number of rollovers over the years.
According to the NHTSA between 1992 and 1996 there was an average of 227,000 rollover crashes per year. These crashes resulted in an average of 9,063 deaths per year (29% of all light vehicle fatalities) and over 200,000 non-fatal injuries per year. Rollover crashes are second only to frontal crashes in level of severity.
The National Accident Sampling System (NASS) data shows rollover crashes typically involve a single vehicle attempting to negotiate a curve in the roadway with the rollover occurring off road. Because so many rollover crashes involve a single vehicle crash investigators have a tendency to disregard the importance of conducting a thorough investigation.
Critical scene evidence is overlooked or even worse just disregarded especially in single occupant crashes since it is felt there is no need for an investigation. Experienced investigators understand how dangerous this attitude can be. Witnesses can appear days after the crash to report another vehicle had cut off the victim or a later inspection of the vehicle can find defects that may have contributed to the rollover event. The loss of physical evidence can make an investigation much more difficult when delayed information is received by the investigating agency.
Rollover collisions are complex events that require careful analysis to accurately reconstruct. It is extremely important to record the physical evidence found at the scene since, like all physical evidence, it is temporary in nature and will fade away over time. A vehicle will travel through the air during the rollover, sometimes more than once, often damaging several sides of the vehicle.
Locating the physical evidence can be more challenging with these factors in mind. Most rollover crashes involve some type of tripping mechanism such as a curb or furrowing into soft ground and this must also be documented. Documentation of vehicle damage must be thorough so it can be matched up with the physical evidence located on the ground.
If occupants are ejected during the rollover sequence it is critical to have documented the physical evidence and vehicle damage to be able to accurately determine where each occupant was seated and when they got ejected. By matching the physical evidence to vehicle damage the Reconstructionist can apply vehicle dynamics and the principles of physics to determine how the occupants would have moved within the vehicle.
This brings up important factors to consider in rollover collisions. It is true that many single vehicle rollover collisions result in no criminal charges being filed but that does not negate the importance of properly and completely investigating the circumstances surrounding the crash. One never knows how an investigation may turn out during the initial stages. Information from witnesses or informants obtained after the crash scene was cleaned up can require evidence that was not gathered to prove or disprove their statements.
In cases where a single vehicle was carrying multiple occupants with all occupants fatally injured it will be important to the families to know how their loved ones died, who was driving, what was their condition while behind the wheel, were there any vehicle defects that contributed to the rollover or roadway defects? These questions cannot be answered without a thorough investigation and the families deserve the answers if they can be found.
Lastly the Ford Explorer and Firestone incidents should have shown everyone how important it is to consider the vehicle and potential part defects in a rollover investigation. Civil cases often arise from rollover fatalities and many times a vehicle defect is claimed as the cause of the fatality. Proper documentation of the physical evidence and vehicle condition after the crash will allow the courts to accurately determine whether there is any liability in these types of cases.
Whether testifying in a criminal case, a civil case, coroner’s inquest or presenting facts to a family the reconstructionist cannot offer an opinion of how the crash occurred, who was driving or whether a defect contributed to the crash without basing his opinion on accepted scientific principles used within the field of crash reconstruction.
If the physical evidence was not gathered there is nothing to base the necessary scientific opinion on and their testimony will not be allowed or will be excluded in court. You do not want to give a family speculation as to how their loved one died if the evidence was there to have allowed you to make a factual determination.
Rollover collisions will continue to occur with the ongoing popularity of light trucks. As crash investigators we must investigate these crashes with thoroughness to be able to answer questions in criminal court, civil court or for the families of those involved.
Although these crashes are complex and challenging to investigate we have a professional duty to do so in a complete and thorough manner. As investigators we must strive not to minimize the importance of investigating rollover crashes.
Eric Paul is a police officer with the Wheaton, IL Police Department assigned to the traffic enforcement unit. He is an ACTAR certified traffic crash reconstructionist.