Your car’s Electronic Stability Control (ESC) system is designed to keep the vehicle upright at all times. Rollover avoidance is accomplished by using a sophisticated system of speed sensors and a control unit that compares the position of the steering wheel to the rotation of the vehicle on its vertical axis.
The real villains here are “spinning out” or “plowing out” on roads with low-friction conditions like dirt, gravel and ice or snow. This is where ESC helps the most: it compensates for a driver who overcorrects as a result of driving while distracted, or driving too fast for conditions.
Existing vehicle safety systems are integrated with use of the control module to reduce the chance of rollover. The Anti-Lock Brake System and the Traction Control system are employed to correct over or under steering. The speed sensors in the ABS system monitor these conditions and apply brakes to the appropriate wheels to slow the car down while preserving steering control, while the Traction Control system checks on roadway grip and reduces engine power to resolve wheel spinning.
Electronic Stability Control is known by several names depending on the car manufacturer. For instance, Honda calls it VSA for Vehicle Stability Assist but it also known as VSE, VSC and ESP for Electronic Stability Program.
The phase-in of the use of ESC in the United Sates began in 2008 and all cars produced in the 2012 model year will be ESC-equipped, by law. Higher-end European cars produced by BMW and Mercedes were equipped with ESC as early as 1995 and by 2007, 50 percent of cars produced in Europe had the feature.
The safety impact of ESC is undisputed since the reduction of rollovers translates into a reduction of serious injuries and fatalities.
Vehicles are equipped with a switch that allows the driver to deactivate the ESC system in the event that the car is stuck on an ice patch. The system would normally be active in these situations due to the spinning wheels and complicate the operator’s ability to free the vehicle. The system is designed to automatically come back on each time the car is started.
To see several examples of tripped rollovers go to safercar.gov. NHSTA says that 95 percent of rollovers are caused by tripping which happens when the vehicle leaves the road and the tires dig into soft soil or strike an object like a curb or guardrail.
With the mandatory use of ESC in the 2012 model year, the frequency of rollovers and the injuries and deaths that usually accompany these types of crashes will certainly be reduced.