Numbered routes that follow state or county lines

[Ellie]

There was previously this thread about roads that follow state or county lines. However, most of the ones brought up were local/county roads. I'm curious how many numbered routes (ideally Interstates or U.S. routes, but state highways are also alright) there are that follow state or county lines for some stretch.

For example, US-71 follows the Texas-Arkansas state line north of Texarkana. For a county example, US-12 does this for a few miles along the Washtenaw-Lenawee line in Michigan. Easy to find state highway examples in Michigan as well, such as the infamous M-102.

[Max Rockatansky]

Not a numbered road but I have a notable historical example for California.  The Stockton-Los Angeles Road was used the baseline south of the Merced River for Mariposa/Merced county line when the latter split from the former in 1855. 

[Ellie]

Not a numbered road but I have a notable historical example for California.  The Stockton-Los Angeles Road was used the baseline south of the Merced River for Mariposa/Merced county line when the latter split from the former in 1855.

Interesting! Seems like some of the road still exists as "Hornitos Road", according to OpenStreetMap anyway. Kinda funny that the route across the Central Valley that made the most sense at the time followed the east side of the valley, given that the current route used (I-5) follows the west side.

[Max Rockatansky]

Not a numbered road but I have a notable historical example for California.  The Stockton-Los Angeles Road was used the baseline south of the Merced River for Mariposa/Merced county line when the latter split from the former in 1855.

Interesting! Seems like some of the road still exists as "Hornitos Road", according to OpenStreetMap anyway. Kinda funny that the route across the Central Valley that made the most sense at the time followed the east side of the valley, given that the current route used (I-5) follows the west side.

The problem at the time was that the Central Valley was a swampy mess with erratic water levels in the rivers and sloughs filling Tulare Lake.  It was easier to form a stage road that followed the foothills of the Sierra Nevada Mountains.  That changed in the 1860s and 1870s when the Southern Pacific built a line through the Central Valley and started selling land to agriculture developers.  By the 1880s the Stockton-Los Angeles Road was largely replaced by the Southern Pacific frontages that comprised early US 99.  To tie this into something numbered, planned CA 65 follows the Stockton-Los Angeles Road corridor along the Mariposa/Merced county line.

[Dough4872]

US 1 follows the border between Philadelphia and Montgomery counties in Pennsylvania along City Avenue.

[Big John]

OK20/AR43

[SEWIGuy]

WI-134 follows the Dane / County line between Cambridge and London

WI-104 follows the Rock / Green County line

[epzik8]

Someone said in the previous thread Maryland/Delaware 54, which does have segments that are fully within one state.

[Dirt Roads]

Not a perfect fit, but VA-83/WV-83 follows the state line off-and-on for about 1/2 mile stretch.  There's six different segments actually running along the border; one segment is over a quarter-mile in length, and two segments about 500 feet long.

[Road Hog]

AR 5 follows the Pulaski/Lonoke county line for several miles.

[WNYroadgeek]

NY 269 on the Niagara/Orleans county line and NY 272 on the Orleans/Monroe county line. NY 18 also briefly overlaps the latter.

[Flint1979]

M-13 follows the Saginaw/Genesee County line for several miles from Willard Road to Johnstone Road, then follows the Shiawassee/Genesee County line from Johnstone Road to where it ends at I-69.

M-102 is 8 Mile Road and follows the Wayne/Macomb line as well as the Wayne/Oakland line.

[TheHighwayMan3561]

MN:

TH 120: Ramsey/Washington
TH 47: Mille Lacs/Kanabec
US 75: Lyon, IA/Rock, MN
TH 1: St. Louis/Itasca
TH 1/TH 6 duplex: Itasca/Koochiching

[Great Lakes Roads]

IN

I-64: Vanderburgh/Gibson
I-69: Gibson/Warrick
SR 4 (eastern): DeKalb/Steuben
SR 110 (eastern): Marshall/Fulton
SR 114 (eastern): Whitely/Huntington
SR 167: Blackford/Jay
SR 218: Huntington/Wells
SR 234 (western): Boone/Hendricks
SR 352: Warren (IN)/Vermillion (IL)
SR 362: Scott/Clark and Jefferson/Clark

[Konza]

Iowa Highway 25 runs along county lines between Iowa 2 and US 34.

At the south end, Ringgold County is to the east, and Taylor County is to the west. 

At the north end, Adams County is to the west, and Union County to the east.

[flan]

MN:

TH 120: Ramsey/Washington
TH 47: Mille Lacs/Kanabec
US 75: Lyon, IA/Rock, MN
TH 1: St. Louis/Itasca
TH 1/TH 6 duplex: Itasca/Koochiching

US 2: Polk / Red Lake
MN 13: Dakota / Ramsey
MN 13: Le Sueur / Scott
MN 19: Le Sueur / Scott
MN 19: Dakota / Rice
MN 19: Redwood / Yellow Medicine
MN 23: Chippewa / Renville
MN 28+SD 10: Roberts, SD / Traverse
MN 60: Le Sueur / Waseca
MN 64: Hubbard / Cass
MN 67: Redwood / Yellow Medicine
MN 87: Hubbard / Cass
MN 104: Swift / Kandiyohi
MN 264: Nobles / Jackson
MN 269: Pipestone / Rock

[plain]

Since the 1970 annexation, VA 150 forms much of the border between Chesterfield County and the City of Richmond, and has been a full freeway along this stretch since the early 80's.

[GaryV]

More Michigan partials:

H13 (multi-county route) follows the Alger/Schoolcraft county line
M-48 and M-129 on the Chippewa/Mackinaw county line
M-65 on the Alpena/Alcona county line
M-72 on the Leelanau/Grand Traverse county line
M-18 on the Crawford/Roscommon county line
M-30 on the Gratiot/Saginaw county line
M-66 on the Barry/Eaton county line
M-89 and (rerouted, concurrent) M-43 on the Barry/Kalamazoo county line
US-12 on the Washtenaw/Lenawee county line
US-127 on the Hillsdale/Lenawee county line

[Flint1979]

More Michigan partials:

H13 (multi-county route) follows the Alger/Schoolcraft county line
M-48 and M-129 on the Chippewa/Mackinaw county line
M-65 on the Alpena/Alcona county line
M-72 on the Leelanau/Grand Traverse county line
M-18 on the Crawford/Roscommon county line
M-30 on the Gratiot/Saginaw county line
M-66 on the Barry/Eaton county line
M-89 and (rerouted, concurrent) M-43 on the Barry/Kalamazoo county line
US-12 on the Washtenaw/Lenawee county line
US-127 on the Hillsdale/Lenawee county line

Actually M-30 ends at M-20. The part south of M-20 is Old M-30 and under county control. MDOT has discussed extending M-30 south to M-46 again though.

[JayhawkCO]

SD 20 runs right along the MT/SD border for a stretch.

[wanderer2575]

More Michigan partials:

H13 (multi-county route) follows the Alger/Schoolcraft county line
M-48 and M-129 on the Chippewa/Mackinaw county line
M-65 on the Alpena/Alcona county line
M-72 on the Leelanau/Grand Traverse county line
M-18 on the Crawford/Roscommon county line
M-30 on the Gratiot/Saginaw county line
M-66 on the Barry/Eaton county line
M-89 and (rerouted, concurrent) M-43 on the Barry/Kalamazoo county line
US-12 on the Washtenaw/Lenawee county line
US-127 on the Hillsdale/Lenawee county line

Actually M-30 ends at M-20. The part south of M-20 is Old M-30 and under county control. MDOT has discussed extending M-30 south to M-46 again though.

It was transferred back to MDOT in the second half of 2022.  I don't know if route shields have been installed yet.

[GaryV]

More Michigan partials:

H13 (multi-county route) follows the Alger/Schoolcraft county line
M-48 and M-129 on the Chippewa/Mackinaw county line
M-65 on the Alpena/Alcona county line
M-72 on the Leelanau/Grand Traverse county line
M-18 on the Crawford/Roscommon county line
M-30 on the Gratiot/Saginaw county line
M-66 on the Barry/Eaton county line
M-89 and (rerouted, concurrent) M-43 on the Barry/Kalamazoo county line
US-12 on the Washtenaw/Lenawee county line
US-127 on the Hillsdale/Lenawee county line

Actually M-30 ends at M-20. The part south of M-20 is Old M-30 and under county control. MDOT has discussed extending M-30 south to M-46 again though.

It was transferred back to MDOT in the second half of 2022.  I don't know if route shields have been installed yet.

It's on the state highway map.

Here's the update from Chris Bessert's site, http://www.michiganhighways.org/listings/M-030.html :

2022 (Sept 27, Oct 12) New! — MDOT completes jurisdictional transfers with the Midland Co Road Commission and Saginaw Co Road Commission to transfer 14.14 miles of Meridian Rd from M-46/Gratiot Rd—Monroe Rd northerly to M-20/Isabella Rd from county to state control as part of an effort to reacquire the remaining portion of Meridian Rd south of M-20 which was not re-transferred back to state control in 2009 (and was transferred from state jurisdiction to the county in 1962). The Saginaw Co transfer of 4.02 miles officially takes place on September 27 while the Midland Co transfer of the remaining 10.12 miles occurs 15 days later on October 12.This occurs just a few months more than exactly 60 years after these segments were cancelled as a state trunkline route and transferred to county control in 1962. Signage along the newly-transferred segment of roadway signifying its inclusion in the route of M-30 is likely to be erected in early-2023. (Thanks Patrick!)

[flan]

North Dakota:

ND 1: LaMoure / Dickey
ND 1+SD 37: Dickey / Brown, SD
ND 3+SD 45: McIntosh / McPherson, SD
ND 5: Burke / Ward
ND 9: Foster / Stutsman
ND 13: Logan / McIntosh
ND 18: Cass / Richland
ND 19: McHenry / Pierce
ND 20: Cavalier / Ramsey
ND 30: Stutsman / Logan
ND 31: Morton / Grant
ND 32: Griggs / Steele
ND 32: Barnes / Ransom
ND 32: Cass / Ransom
ND 41: McLean / Burleigh
ND 46: Stutsman / Logan
ND 46: Stutsman / LaMoure
ND 46: Barnes / LaMoure
ND 46: Barnes / Ransom
ND 46: Cass / Ransom
ND 46: Cass / Richland
ND 50: Burke / Mountrail
ND 50: Ward / Mountrail
US 52: Burke / Ward
ND 67: Slope / Bowman
US 281: Benson / Ramsey
SD 1806: Sioux / Corson, SD

[Flint1979]

More Michigan partials:

H13 (multi-county route) follows the Alger/Schoolcraft county line
M-48 and M-129 on the Chippewa/Mackinaw county line
M-65 on the Alpena/Alcona county line
M-72 on the Leelanau/Grand Traverse county line
M-18 on the Crawford/Roscommon county line
M-30 on the Gratiot/Saginaw county line
M-66 on the Barry/Eaton county line
M-89 and (rerouted, concurrent) M-43 on the Barry/Kalamazoo county line
US-12 on the Washtenaw/Lenawee county line
US-127 on the Hillsdale/Lenawee county line

Actually M-30 ends at M-20. The part south of M-20 is Old M-30 and under county control. MDOT has discussed extending M-30 south to M-46 again though.

It was transferred back to MDOT in the second half of 2022.  I don't know if route shields have been installed yet.

They haven't so technically I wouldn't consider that M-30 until the signs are up. M-30 still has an END sign at M-20. Sometime in the future this might change but as of today I still say M-30's southern terminus is at M-20.

[hbelkins]

There are a couple of state numbered highways that run along the Kentucky-Tennessee line out in far southwestern Kentucky.

A short section of WV/VA 127 runs along the border of those two states.