Vehicle rollover incidents are one of the most dangerous traffic accidents one can be involved in. 63% of rollovers involve some type of injury to an occupant, while 18% of rollover accidents result in death. And while any individual can be involved in a rollover accident, as a group, drivers between the ages of 16-24 are more likely to be involved than drivers over 24. Specialist traffic accident analysts have shown that in many traffic accidents that result in the rollover of the vehicle, they require some type of mechanism that activated the rollover. A trigger mechanism can be a collision with another motor vehicle, a steep incline on soft ground, a curb.
Having said that, a fall mechanism is not always required to cause a vehicle rollover. Instead, an inappropriate driving input, such as an excessive corrective movement, can also cause the vehicle to overturn. Although the cause of a rollover can vary, almost all vehicle rollovers involve a loss of control with approximately 75% of loss of control cases occurring on icy, wet or snowy roads. Due to the high incidence of injuries during a vehicle rollover, new cars are also rated for rollover resistance in addition to the 5-star rating system. In addition, many car manufacturers are now installing rollover sensors, (ROS) to help protect occupants through curtain and head airbag deployment. In some cases, crash investigators can download and interpret crash data from a ROS sensor when investigating a vehicle rollover. For a vehicle to overturn without stopping, the lateral acceleration (α) in Gs must exceed the value of half the width of the vehicle (w) divided by the height of the vehicle’s center of gravity (h).
The illustration above shows a vehicle rollover where the side shown slides into a low curb. The curb acts as an actuation mechanism, causing the top of the vehicle to tip over. Accurately reconstructing the mechanics of a vehicle rollover is critical to understanding how a vehicle sustained damage and injured occupants.
