One-county state highways

[sp_redelectric]

In northwestern Montana:  Montana 40 (Whitefish-Columbia Falls) and 82 (Somers-Bigfork) are both primary state highways in Flathead County.  If you include the secondary highways, there are quite a few more - but my experience was that few people referred to the secondary route numbers (i.e. Secondary Highway 503 for Foys Lake Road, which both starts and ends in southwestern Kalispell but loops around Foys Lake outside of the city).

[Beeper1]

Ok, I'll do Connecticut.  Numbers with an asterisk are highways that continue into another state (in the case of 138, 2 states)

Fairfield: 25, 33, 35*, 37, 39, 53, 55*, 57, 58, 59, 102, 104, 106, 107, 108, 110, 111, 113, 116*, 123*, 124, 127, 130, 135, 136, 137*, 302

New Haven: 22, 40, 42, 68, 70, 77, 100, 103, 114, 115, 121, 122, 139, 142, 146, 150, 152, 162, 172, 188, 243, 313, 334, 337

Hartford: 71A, 75*, 120, 159*, 160, 167, 168*, 173, 174, 175, 176, 177, 178, 185, 187*, 189*, 191, 192*, 194, 218, 220*, 229, 287, 305, 309, 314, 315, 364

Middlesex: 81, 145, 147, 151, 153, 154, 155, 157, 166, 196, 217

Tolland:19*, 31, 186*, 275, 286, 316, 319, 320

New London: 11 27, 78*, 117, 138*, 161, 163, 164, 165*, 184, 201, 213, 214, 215, 216*, 234, 349, 354

Also: I-684 skirts Fairfield County, I-291 is entirely within Hartford County, and one side of NY Route 120A is in Greenwich in Fairfield County.

Windham County, CT:  14*, 14A, 21, 101*, 193*, 198*, 200, 203, 205, 244

[Duke87]

How many state routes are entirely within Cherry Co, NE?

Five: R16C, R16D, S16A, S16B, S16F

No mainline routes, just two recreation routes and three spur routes.

[Takumi]

Norfolk has eight (including an interstate): VA 170, VA 192, VA 194, VA 247, VA 404, VA 405, VA 406, and I-564. Accomack County on the Eastern Shore has at least nine: VA 126, VA 175, VA 176, VA 179, VA 180, VA 181, VA 182, VA 187, VA 316, and I think another 3xx.

[on_wisconsin]

Highway 30 is the only one I can think of off hand for Wisconsin.

To add to what others have posted: WIS-312 in Eau Claire County

[Rover_0]

Utah has quite a few because
(1) Some counties in Utah are larger than some eastern states, and
(2) How some state route numbering schemes work (the 281-299 and 300-series that serve state parks). Those routes seem to be gradually phased out, and it's probably more rare to see a 300-series route cross a county line. Also, you have the relative shortness of routes is also a factor. I'll keep the shorter 281-300-series off these lists.

That said, here are a few off the top of my head (italicized routes are decommissioned, starred routes are at least part of an Interstate Business Route):

Washington County
7, 8, 17, 34*, 59, 212, 219

Iron County
56, 148, 271, 274*

Kane County
11

Garfield County
63

Beaver County
160*

Millard County
64, 99*, 100, 125, 133, 136, 174

Sevier County
76, 118*, 119, 120*, 258, 260

Sanpete County
117, 137

Juab County
41*, 54, 78

Box Elder County
13*, 38, 42, 81, 82, 83, 90, 102*, 240

Cache County
23, 61, 101, 142, 165, 200, 218, 237, 238, 239, 252

Daggett County
43, 44

[nyratk1]

We have a few of these on Long Island, NY also: NY State Routes 110, 111 and 112 and 114 are entirely in Suffolk County. Nassau County has 106, 107, 101, and probably some more that I'm forgetting. I guess the geography of Long Island plays a large role here. Many North/South routes are in one county because the counties cover from the North Shore to the South Shore.

Suffolk also has 108, 231, 347 and 454. Nassau also has 102, 105 and 135.

[Mapmikey]

Norfolk has eight (including an interstate): VA 170, VA 192, VA 194, VA 247, VA 404, VA 405, VA 406, and I-564. Accomack County on the Eastern Shore has at least nine: VA 126, VA 175, VA 176, VA 179, VA 180, VA 181, VA 182, VA 187, VA 316, and I think another 3xx.

The other 3xx routes in Accomack Co are VA 335 west of Painter and VA 389 near Melfa.   Norfolk also has VA 403

Virginia has a bunch of these (crossing an independent city line counts as crossing a county line in this list): 4, 9, 26, 27, 34, 37, 38, 54, 59, 62, 68, 69, 73, 78, 79, 82, 84, 86, 87, 90, 93, 96, 97, 98, 101, 103, 109, 110, 111, 112, 113, 119, 120, 121, 124, 125, 126, 127, 128, 129, 131, 133, 136, 140, 141, 145, 146, 148, 149, 154, 157, 158, 159, 160, 162, 170, 175, 176, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 191, 192, 193, 194, 195, 196, 204, 206, 207, 209, 210, 212, 213, 214, 216, 217, us219, 222, 223, 224, 225, 226, 227, 228, 229, 233, 234, 235, 239, 240, 242, 243, 245, 246, 247, 249, 255, 256, 257, 261, 263, 269, 270, 272, 273, 274, 278, 279, 280, 283, 285, 286, 287, 289, 290, 292, 293, 296, 298, 299; all numbers 300-399 except us301, 307, 311, 321, 331, 337, 338, us340, 345, 351, va360, us360, 361, 369; 400, 401, 403, 404, 405, 406, 409, 412, 413, 415, 420, 598

Two of these have their own business routes...207 and 234

Mapmikey

[Mr_Northside]

Not gonna bother figuring out a bunch of PA ones right now, but I'll throw out PA-60.  It used to be a fairly long, 4 county route (Allegheny, Beaver, Lawrence, Mercer), but with the extension of I-376, it has been shortened to a fairly short one county route.

[Michael]

A few that come to mind right away from NY (along with others I forgot about and found while verifying the ones I did think of):

Broome County:

• NY 201

Cayuga County:

• NY 326
• NY 437
• NY 38A (almost, it's in Onondaga county for 1.97 miles, then re-enters Cayuga County)

Monroe County:

• NY 390
• NY 590

Onondaga County:

• NY 11A
• NY 174
• NY 175
• NY 290
• NY 297
• NY 298
• NY 321
• NY 598
• NY 635
• NY 695

Seneca County:

• NY 96A
• NY 318 (another almost, the western .7 miles of it are in Ontario County)

I-97.

Since the thread is about State Highways, I'll also include IN-520 and Iowa Highways 100, unsigned 461, 922, 965, and all of the other little spurs that were decommissioned in 2003.

I-238????

To get technical, NY considers all routes state routes.  Interstates are ##I and US routes are ##U.  This means I can include the following:

• US 15 in Steuben County
• I-481 and I-690 in Onondaga County
• I-590 in Monroe County
• I-790 in Oneida County
• I-990 in Niagara County (it's actually a single town route, completely in Lockport)

If I wanted to get even more technical, I could include Reference Routes too.

[PurdueBill]

Essex County, Massachusetts:
22
35
97
108
114
127
127A
129A
213
286

And of course, 128 would be on that list if many had their way. 

Many short "spur" routes would qualify under this in many states, like IN 225 and 443 in Tippecanoe County.   (Interestingly, both of these are now spurs off IN 43, with 225 no longer touching 25.

[formulanone]

As said before, Florida probably has more single-county state routes than multi-county SRs; especially the three-digit routes. 2diSRs (is that a term?) are rarely single-county, by comparison.

[Takumi]

The other 3xx routes in Accomack Co are VA 335 west of Painter and VA 389 near Melfa.   Norfolk also has VA 403

For some reason I thought 403's north end was in Virginia Beach. The terrible signage there is something Virginia Beach is especially prone to doing (not that Norfolk isn't). So Accomack has 11 active, which I believe is the most in the state.

Two of these have their own business routes...207 and 234

Interestingly, 234 Business traverses multiple jurisdictions, entering Manassas.

[NE2]

2diSRs (is that a term?)

2dsrs.

[deathtopumpkins]

Norfolk has eight (including an interstate): VA 170, VA 192, VA 194, VA 247, VA 404, VA 405, VA 406, and I-564. Accomack County on the Eastern Shore has at least nine: VA 126, VA 175, VA 176, VA 179, VA 180, VA 181, VA 182, VA 187, VA 316, and I think another 3xx.

The other 3xx routes in Accomack Co are VA 335 west of Painter and VA 389 near Melfa.   Norfolk also has VA 403

Virginia has a bunch of these (crossing an independent city line counts as crossing a county line in this list): 4, 9, 26, 27, 34, 37, 38, 54, 59, 62, 68, 69, 73, 78, 79, 82, 84, 86, 87, 90, 93, 96, 97, 98, 101, 103, 109, 110, 111, 112, 113, 119, 120, 121, 124, 125, 126, 127, 128, 129, 131, 133, 136, 140, 141, 145, 146, 148, 149, 154, 157, 158, 159, 160, 162, 170, 175, 176, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 191, 192, 193, 194, 195, 196, 204, 206, 207, 209, 210, 212, 213, 214, 216, 217, us219, 222, 223, 224, 225, 226, 227, 228, 229, 233, 234, 235, 239, 240, 242, 243, 245, 246, 247, 249, 255, 256, 257, 261, 263, 269, 270, 272, 273, 274, 278, 279, 280, 283, 285, 286, 287, 289, 290, 292, 293, 296, 298, 299; all numbers 300-399 except us301, 307, 311, 321, 331, 337, 338, us340, 345, 351, va360, us360, 361, 369; 400, 401, 403, 404, 405, 406, 409, 412, 413, 415, 420, 598

Two of these have their own business routes...207 and 234

Mapmikey

You missed at least one I can think of off the top of my head - 169 (entirely within Hampton).

[jp the roadgeek]

Ok, I'll do Connecticut.  Numbers with an asterisk are highways that continue into another state (in the case of 138, 2 states)

Fairfield: 25, 33, 35*, 37, 39, 53, 55*, 57, 58, 59, 102, 104, 106, 107, 108, 110, 111, 113, 116*, 123*, 124, 127, 130, 135, 136, 137*, 302

New Haven: 22, 40, 42, 68, 70, 77, 100, 103, 114, 115, 121, 122, 139, 142, 146, 150, 152, 162, 172, 188, 243, 313, 334, 337

Hartford: 71A, 75*, 120, 159*, 160, 167, 168*, 173, 174, 175, 176, 177, 178, 185, 187*, 189*, 191, 192*, 194, 218, 220*, 229, 287, 305, 309, 314, 315, 364

Middlesex: 81, 145, 147, 151, 153, 154, 155, 157, 166, 196, 217

Tolland:19*, 31, 186*, 275, 286, 316, 319, 320

New London: 11 27, 78*, 117, 138*, 161, 163, 164, 165*, 184, 201, 213, 214, 215, 216*, 234, 349, 354

Also: I-684 skirts Fairfield County, I-291 is entirely within Hartford County, and one side of NY Route 120A is in Greenwich in Fairfield County.

Windham County, CT:  14*, 14A, 21, 101*, 193*, 198*, 200, 203, 205, 244

My copy and paste missed that line.  Thanks.

[Mapmikey]

For some reason I thought 403's north end was in Virginia Beach. The terrible signage there is something Virginia Beach is especially prone to doing (not that Norfolk isn't). So Accomack has 11 active, which I believe is the most in the state.

VA 403 has never officially existed north of US 58, despite postings on US 58 indicating otherwise for 20+ years...

Mapmikey

[hobsini2]

Highway 30 is the only one I can think of off hand for Wisconsin.

More I can think of offhand:

WI 15
WI 24
WI 68
WI 74
WI 79
WI 105
WI 111
WI 117
WI 119
WI 122
WI 123
WI 124
WI 125
WI 126
WI 127
WI 129
WI 147
WI 152
WI 155
WI 157
WI 158
WI 159
WI 165
WI 172
WI 186
WI 193
WI 241 (southern terminus in question though)
WI 243
WI 310
WI 341 (unmarked)
WI 794
I-794
I-894

Technically, WI 241 does go just barely into Racine County by 1/4 mile when it ends at I-94.

Another one I can think of is WI 116, entirely in Winnebago County.

[Urban Prairie Schooner]

So many in Louisiana, so will just list those within the Baton Rouge metro region:

East Baton Rouge: 3113, 1209, 410, 408, 3006, 423, 3034, 946, 3064, 3245, 1248, 3045, Spur 327, 948, 3246, 1068, 3164, 426, Bus US 61/190, I-110

West Baton Rouge: 984, 985, 620, 3091, 989-1, 989-2, 990, 986, 987-1 thru 6, 1145, Spur 415, 3237

West Feliciana: 66, 968, 969, 1263, 3057, 421, 965, 966, 967

East Feliciana: 954, 955, 956, 957, 958, 959, 960, 961, 3255, 952, 963, 422, 68, 412

Pointe Coupee: 417, 418, 419, 420, 970, 971, 972, 973, 3050, Spur 77, 981, 413, 414, 81, 976, 978, 979, 416, Bus 1, Bus 10

Iberville: 3000, Spur 3000, 386, 1148, 141, 3075, 3115, 991, 992-3, 3066, Spur 75, 404, 993, 994, 995, 3001, 1251

Saint Helena: 1041, 1042, 1043, 1044, 1047, 448

Livingston: 1019, 1020, 1022, 1023, 1024, 1025, 1026, 1027, 1028, 1029, 1030, 1031, 1032, 1033, 1034, 3002, 3003, 1259, 3282, 3285, 1037, 1038, 1039

Ascension: 928, 930, 931, 933, 934, 935, 935, 937, 3251, 3140, 621, 939, 940, 429, 3038, 941, 943, 944, 3120, 945, 3089

The vast majority of routes in Louisiana are either single parish, less than ten miles long, or both.

[formulanone]

2diSRs (is that a term?)

2dsrs.

Ah, I mentally parsed that "di" as DIgit. Knew that didn't seem right.

[NE2]

I think some do. But they're wrong.

[Revive 755]

Lake County:
IL-131
IL-132
IL-134
IL-137

You forgot IL 60

As for Missouri off the top of my head in no particular order (excluding lettered routes)

St. Louis County:
MO 267 (truncated at the St. Louis City limit.  Some maps show it continuing into the city, but MoDOT has denied this)
MO 340
I-170

St. Louis City
MO 799 (secret designation for the MLK Bridge; IIRC IDOT uses 770 for the bridge)

Jefferson County
MO 104
MO 110

Ste. Genevieve County
MO 144

Lincoln County
MO 147

Cape Girardeau County
MO 74
MO 177

Mississippi County
MO 102
MO 105

[WNYroadgeek]

More for New York:

Niagara County

NY 61
NY 182
NY 18F
NY 429

Erie County:

NY 324
NY 263
NY 179
NY 130
NY 198
NY 400
NY 266
NY 277
NY 391

Chautauqua County

NY 60
NY 394

Steuben County

NY 415
NY 371

Chemung County

NY 328
NY 427

Genesee County

NY 262

Livingston County

NY 258
NY 408
NY 256

Ontario County

NY 444
NY 332

Monroe County

NY 204
NY 531
NY 153
NY 252
NY 252A
NY 383
NY 253
NY 386
NY 250

Wyoming County

NY 362

[Takumi]

VA 403 has never officially existed north of US 58, despite postings on US 58 indicating otherwise for 20+ years...

Indeed, and I even have a photo of that posting with a blue street blade at the edge of the picture, confirming it's entirely in Norfolk.

The shields for VA 403 also look like Norfolk. I don't know why I thought it entered Virginia Beach.

[mapman1071]

Arizona One-county state highways

AZ 30    I-10 Reliver Freeway      
Maricopa

AZ 48           
Yavapai

AZ 51   Piestewa Freeway      
Maricopa

AZ 61
Apache

AZ 64 - 2 Sections
Coconino

AZ 67
Coconino

AZ 68
Mohave

AZ 69   Black Canyon Highway
Yavapai

AZ 72         
La Paz

AZ 74   Carefree Highway
Maricopa

AZ 75
Greenlee

AZ 78
Greenlee

AZ 79
Pinal

AZ B-79 - Florence
Pinal

AZ 80
Cochise

AZ 84
Pinal

AZ 86
Pima

AZ 89
Yavapai

AZ 90
Cochise

AZ 92
Cochise

AZ 95ts - Parker
La Paz

AZ 95s - Parker Dam
La Paz

AZ 95s    Cattail Cove Road
Mohave

AZ 96
Yavapai

AZ 97         
Yavapai

Loop 101    Agua Fria/Pima/Price Freeway
Maricopa

AZ 143   HoHoKam Expressway      
Maricopa

AZ 169
Yavapai

AZ 180a
Apache

AZ 181
Cochise

AZ 186
Cochise

AZ 187
Gila River Reservation

AZ 188
Gila

AZ 189
Santa Cruz

AZ 195   Robert A. Vaughan Expressway
Yuma

Loop 202   Red Mountain/Santan/South Mountain Freeway
Maricopa

Loop 202s   Sky Harbor Blvd   
Maricopa

AZ 210   Barraza-Aviation Parkway
Pima

AZ 261
Apache

AZ 266
Graham

AZ 273
Apache

AZ 277
Navajo

AZ 286
Pima

AZ 287
Pinal

AZ 288
Gila

AZ 289
Santa Cruz

Loop 303       Bob Stump Memorial Parkway
Maricopa

AZ 366
Graham

AZ 373
Apache

AZ 377
Navajo

AZ 386      
Tohono O'odham Reservation   

AZ 387
Pinal

AZ 473
Fort Apache Reservation

AZ 564
Navajo

AZ 587
Gila River Reservation

AZ 989
Pima