The J-turn is an alternative to traditional roadway intersections on a four-lane highway. Instead of motorists crossing fast-moving lanes of traffic to get to the opposing lanes, drivers at a J-turn intersection turn right in the same direction of traffic, merge into the left lane, and then make a U-turn in the direction they intend to travel. Although drivers will have to travel slightly further to get where they want to go, using J-turns can take the same or less time than trying to wait for a safe and appropriate gap to cross traffic.

The point of these turns is to greatly reduce a significant number of severe crashes common when drivers must cross-over busy highways to reach another road.

In the J-turn design drivers turn right in the same direction of traffic, and merge safely into the left lane to prepare to make a left turn in the direction they intended to travel. This option uses an extended deceleration lane, basically adding a third lane on the highway to allow traffic making a left turn onto opposing lanes to safely pull off the mainline, out of the way of high speed traffic.