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), allowing 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 being replaced by two intersections. The beginning one-way traffic at the fourth leg makes the intersections reduce the number of conflicts similar to a three leg T-intersection to improve traffic flow.
- At Legacy Drive and Preston Parkway, Plano, Texas, with Texas U-turn lanes,
- At New Dallas Highway (US-77) and E. Industrial Boulevard TX-340 in Lacy Lakeview, Texas,
- At Stock Road and Winterfold Road in Perth, Australia
- It is the most common intersection design on Utah State Route 85, also called Mountain View Corridor, at begin of construction (those are planned to be later converted, mostly into diamond intersections, by adding the freeway with bridge in the middle).
- At Sarcee Trail and Richmond Road, Calgary, Alberta, Canada,
- Four intersections along Terwillegar Drive in Edmonton, Alberta, Canada
- Four intersections along Manning Drive in Edmonton, Alberta, Canada
- Lake Woodlands Drive at Grogans Mill Road in The Woodlands, Texas;
Town center intersection
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.
- Grogans Mill Road at Research Forest Drive in The Woodlands, Texas;
- Springwoods Village Parkway at Holzwarth Road in Spring, Texas;
- San Elijo Road at Elfin Forest Road in San Marcos, California;
- 170 Street and Stony Plain Road and 100 Ave in Edmonton, Alberta.
- Bared, Joe G. & Kaiser, Evangelos I. (June 2000). "Advantages of The Split Intersection". Public Roads. Vol. 63 no. 6. Federal Highway Administration.
- Bared, Joe & Kaiser, Evangelos (2000). "Benefits of Split Intersections". Journal of the Transportation Research Board. Vol. 1797. Transportation Research Board. pp. 34–41. doi:10.3141/1737-05.
- Rodegerdts, Lee A.; Nevers, Brandon; Robinson, Bruce; Ringert, John; Koonce, Peter; Bansen, Justin; Nguyen, Tina; McGill, John; Stewart, Del; Suggett, Jeff; Neuman, Tim; Antonucci, Nick; Hardy, Kelly & Courage, Ken (2004). "Chapter 10.3.1,". Signalized Intersections: Informational Guide. Federal Highway Administration. FHWA-HRT-04-091. (PDF)