In-&-Back Routes (between states, counties, etc.)

[golden eagle]

There's a similar topic about in the thread about Wyoming 230, which involves highways entering the same state twice. This one is about counties.

Let's say you're driving I-59 north from New Orleans. As you get deeper into Mississippi, you'll enter Lamar County. The next county is Forrest County (where most of Hattiesburg is located, though a part of it is in Lamar). A couple of miles or so later, I-59 curves back slightly to the northwest and re-enters Lamar County, only to curve back northeasterly into Forrest.

The same thing happens here in the Jackson area. I-55 enters Hinds County and eventually multiplexes with I-20 and crosses into neighboring Rankin County. Just inside Rankin, I-55 splits away and proceeds northward and as it does so, it re-enters Hinds County and the city of Jackson.  I-55 also enters Jackson south of the multiplex with I-20 in south Jackson.

A couple of perimeter interstates do this as well. I-285 crosses into Fulton County, GA three times: on the west side of Atlanta coming out of Cobb County, in extreme southeast Atlanta from Clayton County and in north Fulton around Sandy Springs coming out of Dekalb County.

I-465 in the Indianapolis does this as well. The northern ring on the interstates starts in extreme southeastern Boone County from I-865, crosses into Marion County (Indy), cuts into extreme southern Hamilton County and back into Marion to complete its ring around the city until it meets I-865 in Boone County.

[algorerhythms]

I-40 does this in Carroll County, Tennessee, if I remember correctly.

[mapman]

I-80 does this in the Sierra Nevada Mountains of California, oscillating between Placer and Nevada Counties west of Truckee.

On the Nevada side of Lake Tahoe, US 50 alternates between Carson City and Douglas County southwest of downtown Carson City.

[DanTheMan414]

M-134 does this in the eastern Upper Peninsula of Michigan.  It begins at I-75 in Mackinac County, crosses into Chippewa County east of Cedarville, re-enters Mackinac County briefly, & finally enters Chippewa County for good, where it passes through De Tour Village, crosses the De Tour Passage via ferry and travels on Drummond Island, where it ends.

[froggie]

Numerous examples of this....and a Mississippi example the OP missed is I-55 and Carroll County (on either side of Winona).

Far rarer are examples of highways that enter the same state twice.  One that comes to mind is US 52/US 119 along the KY/WV border.

[WillWeaverRVA]

US 250 enters Goochland County twice; once from Henrico County, and again from Louisa County.

[hbelkins]

Numerous examples of this....and a Mississippi example the OP missed is I-55 and Carroll County (on either side of Winona).

Far rarer are examples of highways that enter the same state twice.  One that comes to mind is US 52/US 119 along the KY/WV border.

Yes, this is rather common in Kentucky.

And to cite a state example, West Virginia also has US 50. Traveling west to east you go OH-WV-MD-WV-VA-DC-MD again.

And there are roads that straddle state lines, like WV/VA 127.

[InterstateNG]

The Ohio Turnpike goes Ottawa County/Sandusky/Ottawa/Sandusky over the course of 8 miles east of Toledo.

[florida]

US 90 & I-10 cross Holmes and Washington Counties, back and forth, twice in the FL Panhandle.
US 90 does the same with Leon and Jefferson Counties, east of Tallahassee
FL 21 crosses into Clay County twice near Keystone Heights.
FL 436 crosses into Orange County twice, as does US 441 near Apopka, and FL 434.
FL 46 clips extreme small portions of Volusia County, near Geneva.

That's about it.

[Scott5114]

I-40 crosses back and forth between Donley and Gray Counties in TX a lot.

[US71]

US 71 crosses into, out of and back into Scott County in Arkansas. It also crosses from Miller County into Bowie County, Texas, then back into Miller County.

[leifvanderwall]

Hmmm... this is a tough one. M-48 in the Upper Peninsula : it starts in Chippewa Co. , goes into Mackinac Co. for a mile , and then after Pickford stays and ends in Chippewa Co.

[cu2010]

NY31 does it between Palmyra and Newark, NY. Heading east, you start in Wayne County, then dip briefly into Ontario County when the road bends slightly southward (following the Erie Canal) before reentering Wayne County. It is in Ontario County for less than a mile.

NY3 does it in the Adirondacks, too...going eastward again, it's in Franklin County for a while, then enters Essex County for a while, then reenters Franklin County.

[WISFreeways]

I think I-24 in Chattanooga does this while dipping into Georgia for a bit.

[Hellfighter]

Doesn't I-86/NY-17 dip into Pennsylvania to meet with US-15 before going back into Steuban County?

[Roadgeek Adam]

It comes in at Tioga and dips into Bradford Cty PA, and enters Chemung on the other side

[SP Cook]

In West Virginia:

US 119 (Corridor G) heading south from Charleston in Kanawha goes into Lincoln, then back into Kanawha, then back to Lincoln, before finally entering Boone, then later as mentioned goes from Mingo (in WV) into Pike (in KY) and back several times.

It is unsigned, but US 52 leaves Mingo and enters Logan for less than 100 yards on top of Horsepin Mountain before reentering Mingo.

[tdindy88]

Speaking of Indiana, I-64 in the south goes from Spencer County east of US 231 and into Dubois County, before going back into Spencer and then back into Dubois for good. To make this more interesting, the border between Spencer and Dubois counties is also the time zone line. So you go from Central into Eastern, then back to Central before finally entering Eastern for good. Who says time travel isn't possible?

[City]

I-8 goes east out of San Diego county into Imperial County, goes north, then west back into San Diego County, and then goes north and east back into Imperial County in California.

[agentsteel53]

I-8 goes east out of San Diego county into Imperial County, goes north, then west back into San Diego County, and then goes north and east back into Imperial County in California.

looking at the map, I-8 east seems to switch three full times (SD-Imp-SD-Imp-SD-Imp), but there are only three signs the last I remember (Imp-SD-Imp) because the middle switch is only for a couple dozen feet, as the highway travels almost due north-south.

I-8 west seems to have only two switches (Imp-SD-Imp-SD) by virtue of being a few feet west of I-8 east.  If I recall correctly, there is only one "San Diego County" sign.

meanwhile, to the east of all these switches, firmly in Imperial County, I-8's carriageways are separated by as much as a mile. 

this is all due to the terrain: the SD-Imp county line is a line due north-south but the mountains prevent such easy navigation in real life.

[SSOWorld]

WIS 17 goes from Oneida to Lincoln to Oneida to Langlade to Lincoln (the middle three transitions within a mile)

[hbelkins]

In West Virginia:

US 119 (Corridor G) heading south from Charleston in Kanawha goes into Lincoln, then back into Kanawha, then back to Lincoln, before finally entering Boone, then later as mentioned goes from Mingo (in WV) into Pike (in KY) and back several times.

It is unsigned, but US 52 leaves Mingo and enters Logan for less than 100 yards on top of Horsepin Mountain before reentering Mingo.

I don't think all those transitions on US 119 between Lincoln and Kanawha are signed. IIRC traveling northbound, signage only indicates Boone-Lincoln-Kanawha. The unsigned transition is where the Coal River makes a loop and the highway cuts across that loop.

That's of interest to me since my grandfather Elkins was from Lincoln County.

The entrance of US 52 into Logan County is where WV 44 (old US 119) turns off. WV 44 never enters Mingo.

[jdb1234]

AL 5 goes from Wilcox to Marengo and back to Wilcox county.

Acton Road (not Action Rd) goes Jefferson, Shelby for a few hundred feet and back to Jefferson east of I-459.

[Tom]

Tennessee Hwy 22 in McNairy County starts at the Mississippi state line, crosses into Hardin County, cosigns with US-64 in Crump, reenters McNairy County, and separates from US-64 in Adamsville to follow along the eastern edge of the county.  

[Duke87]

US 6 in Connecticut goes between Tolland and Windham counties twice on the Willmantic Bypass.

US 7 in Connecticut almost enters Fairfield County a second time at the Housatonic River crossing near CT 55 but misses by about 250 feet or so.