You know the feeling all too well. You are driving along an Illinois highway or freeway stuck behind an 18-wheeler. If the road you are on is a two-lane highway, you cannot pass it until you reach a downhill grade. What you should realize, however, is that trucks can jackknife while going downhill, particularly when the road is wet.

A jackknife accident is one of the most potentially catastrophic accidents you can be involved in because it presents one in which the truck driver loses control of his or her truck. Where its trailer goes then and where it winds up in anyone’s guess.

Jackknife mechanics

To better understand what happens when a truck jackknifes, think about the way in which a pocket knife closes. The blade approaches the handle at an ever decreasing angle. Ultimately it goes into the handle. The same thing happens during a jackknife. The back end of the trailer starts moving sideways instead of straight ahead like it should. This can quickly block other traffic lanes, which in turn can cause you to crash into the trailer if you cannot slow down in time.

Even if the trailer skids toward the road’s shoulder during a jackknife, this does not guarantee that you will not hit it. Remember, a huge out-of-control jackknifing truck represents an exceedingly dangerous road hazard. Since you have no way of predicting where the trailer will go or how fast it will go there, you cannot come up with a reliable course of accident avoidance.

Unfortunately, given the size and weight of a loaded trailer in comparison to the size and weight of your passenger vehicle, your risk of serious injury, as well as that of your passengers, in a jackknife or any other kind of truck accident is very high indeed. Consequently, your best strategy when approaching a tractor-trailer from the rear is to give it plenty of room, do not tailgate, and give it the widest possible berth when passing it, especially if you are driving in rain or other inclement weather conditions.