The following are lists of urban regions and metropolitan areas that have developed into a multiple-nuclei of either three (3) or four (4) traditional core communities. By traditional, I mean something other than a suburban edge city (i.e. Tyson’s Corners, VA or Schaumburg, IL.
Most of the Tri-Cities listed form a triangular urban pattern between the primary cities as depicted above in the map of Johnson city/Kingsport/Bristol. Three (3) that don’t follow this typical spatial pattern are the Lehigh Valley of Pennsylvania, the Triple Cities of New York, and Rochester/Dover/Somersworth, New Hampshire. All three of these are linear urban conglomerations along a river valley.
Until recently, I was not aware of any Quad Cities other than the one on either side of the Mississippi in Illinois and Iowa. It turns out the rapidly growing and scenic Prescott area of Arizona also refers to itself as the Quad Cities, as do several other areas.
Ironically, the Prescott area appears to have previously referred to itself as a Tri-Cities, prior to rebranding as a Quad Cities (see the two maps below). Whether this moniker will change to the “Quint Cities” when another town grows larger in the vicinity is unknown. Similarly, the Trestad area of Sweden is also considered a Quad City or Fyrstad when the nearby city of Lysekil is included.
Business map for Prescott-Prescott Valley-Chino Valley (Tri-Cities) of Arizona in 2004.
2019-2020 Quad Cities Business Map – Source: prescottmap.com
Business map for the re-branded Quad Cities of Prescott-Prescott Valley, Chino Valley, and Dewey-Humboldt of Arizona for 2019-2020.
The list below identifies the name of the region/metro area, the core cities, and then the most recent population estimate for the metro area (if applicable or known). Some of the places listed are subsections of larger metropolitan areas.
One last items of note are urban areas that we think of as Tri-Cities that don’t brand, market, promote, or advertise themselves in that way. I’ve always thought of Tampa-St. Pete-Clearwater as a tricity or triopolis. If it was at one time, it doesn’t seem to be any longer. Another example is the San Bernardino-Riverside-Ontario metropolitan area in Southern California (today they are known as parts of the “Inland Empire”). Lastly, the Huntington, WV/Ashland, KY/Ironton, OH area could have or should have been considered a tricity. It would be especially unique as each city forming the triopolis is in a different state.
As always, any additions, corrections, or updates are most welcome, particularly from outside of North America.
Tri-Cities (Tricity or Triopolis)
- Capital District Tricity, NY – Albany/Schenectady/Troy = 883,000 (2018)
- Chandigarh Tricity, India – Chandigarh/Panchkula/Mohari = 1,612,000 (2011)
- Damman Tricity, Saudi Arabia – Damman/Dhrahan/Khobar
- Dubai Tricity, UAE – Dubai/Ajman/Sharjah
- Golden Triangle, TX – Beaumont/Port Arthur/Orange = 410,000 (2018)
- Historic Triangle, VA – Williamsburg/Yorktown/Jamestown
- Kashubian Tricity, Poland – Wejherowo/Rumia/Reda = 120,000 (2012)
- Lehigh Valley Tricity, PA/NJ – Allentown/Bethlehem/Easton = 843,000 (2018)
- Piedmont Triad, NC – Greensboro/Winston-Salem/High Point = 1,439,000 (2018)
- Raipur Tricity, India – Raipur/Bhilai/Durg = 3,187,000 (2011)
- Research Triangle, NC – Raleigh/Durham/Chapel Hill = 1,938,000 (2018)
- Trestad, Sweden – Trollhattan/Uddevalla/ Vanersborg = 99,000
- Tri-Cities, BC – Coquitlam/Port Coquitlam/Port Moody = 234,000 (2016)
- Tri-Cities, CA(1) – Oceanside/Vista/Carlsbad
- Tri-Cities, CA(2) – Fremont/Newark/Union City = 233,000 (2016)
- Tri-Cities, CO – Firestone/Frederick/Dacano
- Tri-Cities, IL – St. Charles/Geneva/Batavia
- Tri-Cities, MI(1) – Saginaw/Midland/Bay City = 378,000 (2018)
- Tri-Cities, M(2) – Grand Haven/Spring Lake/Ferrysburg
- Tri-Cities, NE – Grand Island/Kearny/Hastings = 173,000 (2018)
- Tri-Cities, NH – Rochester/Dover/Somersworth
- Tri-Cities, ON – Kitchener/Cambridge/Waterloo = 524,000 (2016)
- Tri-Cities, OK – Tuttle/Newcastle/Blanchard
- Tri-Cities CDP, OR – Myrtle Creek/Canyonville/Riddle
- Tri-Cities, TN/VA – Johnson City/Kingsport/Bristol (combined VA and TN) = 509,000 (2018)
- Tri-Cities, VA – Petersburg/Hopewell/Colonial Heights
- Tri-Cities, WA – Richland/Pasco/Kennewick = 357,000 (2018)
- Tricity Nepal – Bagging/Beni/Kusma
- Tricity, Poland – Gdansk/Gdynia/Sopot = 1,098,000 (2017)
- Triple Cities, NY – Binghamton/Endicott/Johnson City = 240,000 (2018)
- Warangal Tricity, India – Warangal/Hanamkonda/Kazipet
- West Yorkshire Tricity, UK – Leeds/Wakefield/Bradford
- Quad Cities, AL – Florence/Muscle Shoals/Tuscumbia/Sheffield
- Quad Cities, AZ – Prescott/Prescott Valley/Chino Valley/Dewey-Humboldt = 232,000 (2018)
- Quad Cities, IA/IL – Davenport/Moline/Rock Island/Bettendorf = 381,000 (2018)
- Quad Cities, MN – Eveleth/Virginia/Gilbert/Mountain Iron
- personal knowledge