Many newer vehicles and all vehicles sold in the United States after 2012 will have some sort of Electronic Stability Control, or ESC. ESC has been around since 1987 and was first introduced to passenger vehicles by Mercedes-Benz. There are a number of other names and acronyms for ESC, for instance; GM has “Stabilitrak”, and FORD has “AdvnaceTrac”. Other manufacturers have their own version of ESC but they all do the same thing.
ESC and traction control differ greatly in that traction control only works while accelerating and provides a temporary transfer of power to either front or rear drive wheels. Electronic Stability Control is an added sensor in a vehicle that monitors the steering input, engine RPMs, and yaw rate of the vehicle and is capable of independently applying braking power to any of the four wheels in order to keep the vehicle moving in the direction the steering wheel is turned.
Based on research I have conducted and in speaking with driving instructors from FLETC (Federal Law Enforcement Training Center) it is important to know that at speeds below 35 mph an ESC equipped target vehicle may not fully rotate out of the way of the PIT vehicle due to the ESC working to keep the target vehicle moving in the direction of the steering wheel position. The potential is there for the target vehicle to stop in a T type position where the driver or passenger side of the target vehicle is now only a “hoods” length away from the officer conducting the PIT.
There is no way to know for sure if the vehicle you are about to PIT is equipped with ESC unless you study all makes of vehicles and the years they were equipped with ESC. Should you find yourself in a situation where you have attempted a PIT on an ESC car and have wound up in the dreaded T type of position on the target vehicle there are two options; one is to turn toward the rear of the target vehicle and attempt to power through and out of the range of the driver or passengers in the vehicle. The other would be a hasty back up and possibly a J turn if there is room. Just remember if you are the PIT car there may be cars behind you that could prevent backing.
At higher speeds the target vehicle of a PIT will fully rotate 360 degrees, if the PIT is done correctly, and will simply come out of the rotation pointing in the same direction it was going prior to the PIT, thanks to ESC. There are several you tube videos of police chases where the target vehicle was PIT multiple times and only stopped when pushed sideways into a fixed object leaving the PIT car in that dangerous T situation.
Written by Robert Smyth – a 24 year law enforcement officer and trainer with the Pinellas County Sheriff’s Office.