Three-level diamond diagram. Arrows are for traffic driving on the right.
Three-level diamond diagram. Arrows are for traffic driving on the right.

A three-level diamond interchange is a type of highway interchange where through traffic on both main roads is grade-separated from intersections which handle transferring traffic.[1] It is similar in design to a three-level stacked roundabout except for its use of (usually signalled) conventional intersections, and can be thought of as two diamond interchanges fused together.

Road enthusiasts sometimes use the terms volleyball interchange or split-level diamond interchange to refer to these interchanges.[2]

Description

In a three-level diamond interchange, the two main roads are on separate levels, and on a third level, usually in the middle, there is a square of one-way roads. The square circulates clockwise where traffic drives on the left, or anticlockwise where it drives on the right. At each corner of the square is the terminal of an exit ramp from one main road and an entrance ramp to the other main road.

Traffic transferring from one road to the other to make an overall right turn only passes through one corner of the square, at which point a right turn is made. Transfer traffic making an overall left turn must proceed straight through the first intersection it encounters, turn left at the next, and then proceed straight through a third intersection to enter the other main roadway.

Its two-level variant is the split diamond interchange.

Its at-grade variant is the town center intersection (TCI).

Examples

Location First Route Second Route Notes
Cedar Rapids, Iowa, United States I-380 Iowa 100 Collector/distributor roads intersect.
Detroit, Michigan, United States I-75 (Walter P. Chrysler Freeway) M-102 (8 Mile Road) I-75 uses frontage roads
M-1 (Woodward Avenue) M-102 (8 Mile Road)
M-10 (John C. Lodge Freeway) M-102 (8 Mile Road) Includes slip ramps from northbound M-10 to westbound M-102, eastbound M-102 to southbound M-10, and westbound M-102 to northbound M-10. M-10 uses frontage roads
Redford Township, Michigan, United States I-96 (Jeffries Freeway) US 24 (Telegraph Road) I-96 uses frontage roads
Jefferson City, Missouri, United States US 50 / US 63 northbound US 54 / US 63 southbound A flyover ramp has been added to allow westbound US 54 traffic to join US 50 east, bypassing one intersection. This addition necessitates the use of a nearby city street to transfer from westbound US 50 to westbound US 54.
Asheville, North Carolina, United States I-240 US 70 I-240 exit 7
High Point, North Carolina, United States I-74 / US 311 I-85 BL / US 29 / US 70 I-74 exit 71B
Oklahoma City, Oklahoma, United States SH-74 Kilpatrick Turnpike A flyover ramp has been added to allow westbound Kilpatrick Turnpike traffic to join State Highway 74 south, bypassing one intersection.
Marple Township, Delaware County, Pennsylvania, United States I-476 US 1 I-476 exit 5
Robinson Township, Washington County, Pennsylvania, United States PA Turnpike 576 US 22 PA 576 exit 6; partially completed, temporary terminus of PA 576
Austin, Texas, United States US 183 Loop 275 Includes frontage roads at-grade with interchange
Dallas, Texas, United States Loop 12 (Buckner Boulevard) I-30 / US 67 Includes frontage roads at-grade with interchange
Del Valle, Texas, United States 71 Toll Lanes SH 130 Toll Includes frontage roads at-grade with interchange. A flyover ramp was added to allow eastbound SH 71 traffic to join SH 130 north.
El Paso, Texas, United States US 62 (East Paisano Drive) I-110 Includes frontage roads at-grade with interchange
Frisco, Texas, United States Sam Rayburn Tollway SH 289 (Preston Road) Includes frontage roads at-grade with interchange (signed as SH 121 for the first route)
Houston, Texas, United States SH 6 / FM 1960 US 290 (Northwest Freeway) Includes frontage roads at-grade with interchange. A flyover ramp was added to allow northbound SH 6 traffic to join U.S. 290 east.
Beltway 8 Hardy Toll Road Includes frontage roads at-grade with interchange. A flyover ramp was added to allow eastbound Beltway 8 traffic to join Hardy Toll Road north.
FM 1960 Hardy Toll Road Includes frontage roads at-grade with interchange.
Fort Bend Tollway Sam Houston Tollway Includes frontage roads at-grade with interchange (signed as Hillcroft Avenue and Beltway 8, respectively, for the first and second routes).
Fort Bend Parkway Toll Road SH 6 Includes frontage roads at-grade with interchange.
Grand Parkway Toll Road Fort Bend Westpark Tollway Includes frontage roads at-grade with interchange (signed as SH 99 and F.M. 1093, respectively, for the first and second routes). A flyover ramp was added to allow southbound Grand Parkway traffic to join Westpark Tollway east.
I-10 (Katy Freeway) SH 6 Includes frontage roads at-grade with interchange.
I-45 (North Freeway) FM 1960 Includes frontage roads at-grade with interchange.
I-45 (North Freeway) Greens Road Includes frontage roads at-grade with interchange.
Memorial Drive Houston Avenue Includes frontage roads at-grade with interchange.
Sam Houston Tollway US 90 (Crosby Freeway) Includes frontage roads at-grade with interchange (signed as Beltway 8 for the first route).
Sam Houston Tollway
US 90 Alt.
Includes frontage roads at-grade with interchange (signed as Beltway 8 for the first route).
SH 249 (Tomball Parkway) FM 1960 Includes frontage roads at-grade with interchange.
Lubbock, Texas, United States US 62 / US 82 Loop 289 Includes frontage roads at-grade with interchanges.
US 84 I-27 / US 87
Loop 289 I-27 / US 87
Loop 289 US 82 / SH 114
Midland, Texas, United States Loop 250
SH 158 / Bus. SH 158
Includes frontage roads at-grade with interchange. The western terminus for Business SH 158 is at this interchange. Eastbound SH 158 merges with southbound Loop 250.
Pasadena, Texas, United States Sam Houston Tollway SH 225 (Pasadena Freeway) Includes frontage roads at-grade with interchange (signed as Beltway 8 for the first route).
Richardson, Texas, United States US 75 Spring Valley Road Includes frontage roads at-grade with interchange
Round Rock, Texas, United States US 79 SH 130 Toll Includes frontage roads at-grade with interchange
Sherman, Texas, United States US 75 US 82 Includes frontage roads at-grade with interchange
Sugar Land, Texas, United States I-69 / US 59
US 90 Alt.
Includes frontage roads at-grade with interchange
Tomball, Texas, United States SH 99 Toll (Grand Parkway) Tomball Tollway Includes frontage roads at-grade with interchange (signed as SH 249 for the second route).
Tyler, Texas, United States Loop 49 Toll I-20 Includes frontage roads at-grade with interchange.
Waco, Texas, United States US 84 SH 6 Includes frontage roads at-grade with interchange
Alexandria, Virginia, United States I-395 (Shirley Highway) Seminary Road I-395 exit 4
Fairfax County, Virginia, United States SR 286 (Fairfax County Parkway) US 29 The south end of West Ox Road also meets this interchange.
Welch, West Virginia, United States US 52 (King Coal Highway) US 121 (Coalfields Expressway) As of 2011, grading has been completed for interchange but interchange itself has not been constructed.
Wheeling, West Virginia, United States I-470 US 250 / WV 2 Entire interchange is elevated above city streets.
Wauwatosa, Wisconsin, United States US 45 WIS 190 (Capitol Drive) An access road for the adjacent Harley-Davidson plant is also part of the interchange.
Belmont, Queensland, Australia Gateway Motorway (M1) Old Cleveland Road (State Route 22) Two of the ramps are two-way for a short distance to allow access from the interchange to and from local streets.
Düsseldorf-Stockum, Germany Autobahn 44 Bundesstraße 8 At 51°16′16.9″N 6°45′1.8″E / 51.271361°N 6.750500°E / 51.271361; 6.750500; rare design in Germany

Many examples of this interchange type can also be found in Texas; however, the interchanges almost always include the frontage roads as well. If the traffic amounts increase, the interchange is usually converted into a stack interchange, also as the second level of the High Five Interchange.

References

  1. ^ Indiana Department of Transportation, "Interchanges" (PDF). (203 KiB), pages 21 and 22
  2. ^ Oglesby, Scott. "Volleyball Interchange". Kurumi's Field Guide to Interchanges. Retrieved 23 August 2013.[self-published source]