Split intersection

A split intersection is a rarely-built at-grade variant of the diamond interchange. Compared to a conventional four-leg intersection or road crossing, the arterial road is split into separate carriageways by 200 to 300 feet (61 to 91 m), which allows a queue of left turning vehicles behind a completed turn into the crossroad without any conflict to oncoming traffic. On the crossroad, the four-leg intersection is replaced by two intersections.

The beginning of one-way traffic at the fourth leg makes the intersections reduce the number of conflicts, similarly to a three-leg T-intersection, to improve traffic flow.

A town center intersection (TCI) is similar to a split intersection; however, both the arterial road and the crossroad are split into separated one-way streets. The resulting grid, most often implemented in a city, reduces conflicts to two directions per intersection.

The TCI's grade-separated variant is the three-level diamond interchange.