I was going through some old posts and I saw that I created a similar post in 2011. Since we've had a 2020 census, I decided to update the list of the most populated counties in each that doesn't have an interstate, along with 2020 population. A few counties did receive interstates and I will make note of those that were replaced.
(Please let me know if I made any mistakes.)
ALABAMA: Houston County (107,202)--includes Dothan
ALASKA: No interstates
ARIZONA: Gila County (53,272)
ARKANSAS: Garland (100,180)--includes Hot Springs; replaced Craighead County (Jonesboro) with the signing of I-555
CALIFORNIA: Ventura (843,843)--includes Oxnard and Ventura
COLORADO: Boulder (330,758)--includes Boulder
CONNECTICUT: Litchfield (185,186, only county in state without an interstate)--includes Torrington
DELAWARE: Sussex (237,378)
FLORIDA: Clay (218,245)--suburban Jacksonville
GEORGIA: Forsyth (251,283)--suburban Atlanta
HAWAII: Hawaii (200,629)--includes Hilo
IDAHO: Bonner (47,110)
ILLINOIS: Jackson (52,974)--includes Carbondale & Southern Illinois University
INDIANA: Howard (83,658)--includes Kokomo; replaced Monroe (Bloomington) with the signing of I-69
IOWA: Dubuque (97,700)--includes namesake Dubuque
KANSAS: Reno (61,898)--includes Hutchinson
KENTUCKY: Pulaski (65,034)--includes Somerset; replaced Daviess (Owensboro) with the signing on I-169
LOUISIANA: Terrebonne (109,580)--includes Houma
MAINE: Oxford (57,777)
MARYLAND: Charles (166,617)--suburban Washington, DC
MASSACHUSETTS: Barnstable (228,996)--includes Cape Cod
MICHIGAN: Lenawee (99,423)--includes Adrian
MINNESOTA: Carver (106,922)--suburban Minneapolis
MISSISSIPPI: Lowndes (58,879)--includes Columbus; replaced Lee (Tupelo) with the signing of I-22
MISSOURI:Lincoln (76,770)--suburban St. Louis; replaced Cass County with the signing of I-49
MONTANA: Flathead (104,357)--includes Kalispell
NEBRASKA: Dodge (37,160)--includes Fremont; replaces Scotts Bluff due to population
NEVADA: Nye (51,590)--includes Pahrump; replaces Carson City with the signing of I-580
NEW HAMPSHIRE: Strafford (130,889)
NEW JERSEY: Atlantic (274,534)--includes Atlantic City
NEW MEXICO: San Juan (121,661)--includes Farmington
NEW YORK: Tompkins (105,740)--includes Ithaca
NORTH CAROLINA: Union (238,267)--suburban Charlotte
NORTH DAKOTA: Ward (69,919)--includes Minot
OHIO: Columbiana (101,877)
OKLAHOMA: Garfield (62,845)--includes Enid
OREGON: Deschutes (198,253)--includes Bend
PENNSYLVANIA: Cambria (133,472)--includes Johnstown
RHODE ISLAND: Newport (85,643)--includes Newport
SOUTH CAROLINA: Horry (351,029)--includes Myrtle Beach
SOUTH DAKOTA: Brown (38,301)--includes Aberdeen
TENNESSEE: Tipton (60,970)--suburban Memphis
TEXAS: Collin (1,064,465)--suburban Dallas
UTAH: Cache (133,154)–includes Logan and Utah State University
VERMONT: Rutland (60,572)--includes namesake Rutland
VIRGINIA: Loudoun (420,959)--suburban Washington, DC
WASHINGTON: Kitsap (275,611)--includes Bremerton
WEST VIRGINIA: Jefferson (57,701)
WISCONSIN: Grant (51,021)--includes Platteville; replaced Outgamie (Appleton) with the signing of I-41
WYOMING: Park (29,331)--includes Cody and Powell
Grant County, WI is not worthy of an Interstate. Platteville (and by extension the county) have their populations bloated by the UW-Platteville student body. the city could easily be down to 4000 permanent residents without the school. There is hardly any traffic on 151 whatsoever between Dodgeville and Dickeyville (Most traffic turns off on 18 at the former, 61 at the latter)
Dubuque, on the other hand, could have a freeway be designated as an interstate from the south and/or west also if more traffic went that way. Much of both 20 and 61 are at-grade and the terrain in Dubuque doesn't support such infrastructure. 151 from CRapids is also sketchy and needs serious rebuilds before it can get the designation (as a 3di of 80?) and its traffic load is low too. The traffic doesn't really get heavy outside commuter traffic.
Quote from: golden eagle on January 30, 2022, 09:03:11 PM
ALASKA: No interstates
Alaska has unsigned Interstates. They're not required to meet normal Interstate standards, or even be freeways.
The Interstate-less borough with the largest population is Juneau City and Borough, population 32,255. Kenai Peninsula Borough (includes Seward and Soldotna) has the largest population (58,799) for a borough with only a non-freeway Interstate. The three largest boroughs each have at least one unsigned Interstate that includes one or more freeway segments.
The census areas within the Unorganized Borough have a combined population of 76,681. Each of those census areas have less population than the Juneau borough. Some of them have Interstate segments, none of them freeway.
Quote from: golden eagle on January 30, 2022, 09:03:11 PM
UTAH: Uintah (35,620)
This is wrong. Cache County has no interstates and is far bigger (133,154). It's where Logan and Utah State University are located.
Uintah, however, is the most populous Utah county that is not accessible by a four-lane road.
Quote from: US 89 on January 30, 2022, 10:58:30 PM
Quote from: golden eagle on January 30, 2022, 09:03:11 PM
UTAH: Uintah (35,620)
This is wrong. Cache County has no interstates and is far bigger (133,154). It's where Logan and Utah State University are located.
Uintah, however, is the most populous Utah county that is not accessible by a four-lane road.
I stand corrected. I will make the correction. Thank you.
Carver County, MN has the US 212 freeway bypass of Chaska. No sense in putting an I- on that, because Chaska isn't big enough to justify it.
I figured Wisconsin's would be Dodge, pop. 88k, but I-41 barely skirts the northeast corner.
Regarding Connecticut -- assuming they go through with shifting to COGs as county equivalents on 1/1/2023, "Northwest Hills" will be the only COG in Connecticut without an interstate.
Quote from: thspfc on January 31, 2022, 07:10:03 AM
I figured Wisconsin's would be Dodge, pop. 88k, but I-41 barely skirts the northeast corner.
I-41 passes through Dodge County, WI and the county lines are signed.
Mike