Northern, eastern, southern, and westernmost points on a state's highway system

[froggie]

New York:

North: 4-way tie (NY 30, NY 189, NY 276, NY 374)
South: NY 440
East: NY 27
West: 4-way tie (NY 5, NY 17, NY 426, NY 430)

As seen graphically with a METAL vertex extremes search result based on TM data in New York:

Can confirm the northern extreme.  As with VT/QC (mentioned upthread), the NY/QC border does not exactly follow a latitude parallel.

Northern:  due to surveying errors and the Canadian border not exactly following an exact straight parallel, it's potentially one of three crossings:  I-89, VT 108, or VT 253.

Narrowed it down to VT 108.

S: A bunch along the VA/NC border, but I think that due to surveying errors, US-258 may be the furthest south.

I came up with US 29, which just barely beat out US 15.

North Carolina:
Northernmost: Hard to say, but based on surveying errors, my guess is the northern terminus of NC 194

Did an analysis and came up with the same thing...NC 194.

[skluth]

Wyoming and Colorado are the easiest. If you hit a state line, you are at a tie for either the northernmost, southernmost, easternmost, or westernmost point on the state's highway system. Kansas is the same except if the highway hits the Missouri River. There is technically a small portion of Kansas east of the main KS/MO state line thanks to a small bend in the Missouri River, but no highways exist in that bend.

[TheHighwayMan3561]

Wyoming and Colorado are the easiest. If you hit a state line, you are at a tie for either the northernmost, southernmost, easternmost, or westernmost point on the state's highway system. Kansas is the same except if the highway hits the Missouri River. There is technically a small portion of Kansas east of the main KS/MO state line thanks to a small bend in the Missouri River, but no highways exist in that bend.

I think a thread was posted here about the tiny surveying errors that make Wyoming a less than perfect rectangle if you know where to look, so I'd be interested if any state routes cross those imperfections.

[US 89]

All of Utah's extremes theoretically should be ties. But because 19th century surveying wasn't necessarily an exact science, we have:

North: I-15 - latitude 42.001N (should be 42N)
South: US 163 - latitude 36.998N (should be 37N)
East: US 491 - longitude 109.041W (should be 109.05W)
West: SR 56 - longitude 114.052W (should be 114.05W)

[Dirt Roads]

Virginia

W: US-58 at the VA/TN Border.

I'm sure the OP wanted state routes, not US routes.  If you do include secondary routes, Lee County SR-872 (North Cumberland Drive) loops up from the new section of US-58 in Tennessee back into Virginia and then back down into Tennessee (at the westernmost point) into the village of Cumberland Gap.  Otherwise, you are looking at the VA-70 at the point where it intersects US-58 in Jonesville, Virginia (some 33 miles west of westernmost point of Virginia).  Are there any of these northern/southern/eastern/westernmost routes that are further away from the actual geographic extreme?

[webny99]

New York:

North: 4-way tie (NY 30, NY 189, NY 276, NY 374)
South: NY 440
East: NY 27
West: 4-way tie (NY 5, NY 17, NY 426, NY 430)

As seen graphically with a METAL vertex extremes search result based on TM data in New York:

You know, it's funny, Fort Niagara feels very much like an extreme, but it's actually not even close because of the shape of the state.

[Dirt Roads]

Virginia

W: US-58 at the VA/TN Border.

<snipped>  If you do include secondary routes, Lee County SR-872 (North Cumberland Drive) loops up from the new section of US-58 in Tennessee back into Virginia and then back down into Tennessee (at the westernmost point) into the village of Cumberland Gap.  Otherwise, you are looking at the VA-70 at the point where it intersects US-58 in Jonesville, Virginia (some 33 miles west of westernmost point of Virginia).  Are there any of these northern/southern/eastern/westernmost routes that are further away from the actual geographic extreme?

Back in the day, the term "hiking the Cumberland Gap" actually meant hiking the length of Ridge Trail from the old US-25E crossing all the way up past White Rocks and down through Ewing Trail to the eastern parking area (mostly along the Virginia/Kentucky border).  My memory is fading, but I recall this was about 28 miles when I did the hike.  After the tunnel was constructed, the term "hiking the Cumberland Gap" means a much, much shorter hike over the historical gap crossing.  All which reminds me, that section of US-25E was formerly the westernmost route in Virginia (oops, didn't I just throw shade on Thing342 for the same mistake? Sorry).

[Dirt Roads]

West Virginia:

Northernmost:  WV-2 at Old US-30 (with loopback on-ramp to US-30 westbound) in Chester.
Southernmost:  WV-16 at the Virginia Border just south of Main Street in Bishop.
Easternmost:  WV-230 (Shepherdstown Pike) at US-340 just south of Halltown.  (US-340 at the Virginia border and unposted US-340 Alt in downtown Harpers Ferry are further east).
Westernmost:  US-37 over the Tug Fork at the Kentucky Border between Fort Gay WV and Louisa KY (US-52 just north of the Tabors Creek bridge is further west).

[mgk920]

Only state maintained highways count. (Yes, I know there some oddities like the Illinois tollways not being state maintained, but please just use good judgement and don't ask questions you know the answer to.)
WI:
Northern is WI-13 at the Sand River in Bayfield County
Eastern is WI-42 at the Washington Island ferry dock
Southern is a tie between several if you aren't being picky, but if you factor in the curve of the earth, WI-32 at the Illinois border is the winner.
Western is the US-10 bridge over the St. Croix River at Prescott.

More so because of a surveying error, WI 32 at the Illinois state line is indeed the southernmost point on the Wisconsin state highway system.  The Illinois-Wisconsin state line was supposed to be at 42.5 degrees north.  The error drew the actual line about a half mile south of that at the Lake Michigan shore and slightly north of 42.5N at the Mississippi River shoreline.

Mike

[1995hoo]

Virginia

W: US-58 at the VA/TN Border.

I'm sure the OP wanted state routes, not US routes. ....

Except the OP used a US route in the original post!

[hotdogPi]

Virginia

W: US-58 at the VA/TN Border.

I'm sure the OP wanted state routes, not US routes. ....

Except the OP used a US route in the original post!

state's highway system = all routes in state
state highway system = state routes only

[oscar]

For Hawaii:

Northernmost: HI 560 on Kauai, near the intersection with Alealea Rd.

Westernmost: HI 50 on Kauai, where it ends at an entrance to the Pacific Missile Range military facility (the populated island of Niihau is farther west, but it's all under private ownership and has no state-maintained routes)

Easternmost: HI 130 on the Big Island, near its intersection with county route 132 in Pahoa

Southernmost: HI 11 on the Big Island, about 0.8 mile west of the intersection with county-maintained South Point Rd.

Alaska is trickier, since there are a lot of state-maintained roads with no route numbers (other than internal six-digit inventory numbers). They would probably extend the reach of the state highway system well beyond the numbered route system, to Captain Jack Rd. in Unalaska or maybe farther west in the Aleutians, to Utqiagvik (Barrow) in the far north, to the Canadian border in Hyder for the easternmost point, and somewhere on Annette Island south of Ketchikan. But I'll have to prowl through the state road inventory to nail down these down, when I have more time.

[Flint1979]

Virginia

W: US-58 at the VA/TN Border.

I'm sure the OP wanted state routes, not US routes.  If you do include secondary routes, Lee County SR-872 (North Cumberland Drive) loops up from the new section of US-58 in Tennessee back into Virginia and then back down into Tennessee (at the westernmost point) into the village of Cumberland Gap.  Otherwise, you are looking at the VA-70 at the point where it intersects US-58 in Jonesville, Virginia (some 33 miles west of westernmost point of Virginia).  Are there any of these northern/southern/eastern/westernmost routes that are further away from the actual geographic extreme?

The OP included a US highway on his list, US-10.

[Mapmikey]

South Carolina:
E - SC 179
S - US 17
W - US 76
N - US 176 (old SC 251 which is now S-23-17 used to hold this distinction)

[Crown Victoria]

South Carolina:
E - SC 179
S - US 17
W - US 76
N - US 176 (old SC 251 which is now S-23-17 used to hold this distinction)

If we assume the OP's intent for "state-maintained" to mean ANY route maintained by a state (as opposed to a county, city, township, etc.) regardless of signage, then old SC 251/current S-23-17 beats US 176 as it's still maintained by SCDOT.

[Brandon]

I appreciate you making it easy for me to figure out Illinois' northern most.

The northern most would be IL-137 (Sheridan Road) which becomes WI-32 going into Wisconsin.
The eastern most could possibly be IL-33 or US-50 down by Vincennes, Indiana.
The southern most would have to be US-62 south of Cairo.
The western most looks like it is US-24 through Quincy.

Due to the errors in the state line, it's IL-35 over in East Dubuque for the northernmost point.

[jp the roadgeek]

CT is easy

Northernmost: Anywhere at the MA border not bordering the Southwick jog

Easternmost: Anywhere along the RI border from where CT 216 crosses north.

Southernmost and Westernmost: I-95 at the NY border.  But southernmost state route would be CT 136 in Rowayton and westernmost would be CT 15 at the NY border.

[thspfc]

CT is easy

Northernmost: Anywhere at the MA border not bordering the Southwick jog

Easternmost: Anywhere along the RI border from where CT 216 crosses north.

Southernmost and Westernmost: I-95 at the NY border.  But southernmost state route would be CT 136 in Rowayton and westernmost would be CT 15 at the NY border.

I-95 in CT appears to be the only instance of the same highway being multiple of the most extreme points.

[US 89]

I-95 in CT appears to be the only instance of the same highway being multiple of the most extreme points.

AR 43 is a legitimate contender. I don't feel like going through the entire Arkansas-Missouri border to see if another crossing is barely further north, but it is definitely the westernmost.

[CNGL-Leudimin]

Isn't I-684 the Westernmost highway in Connecticut? Even if it doesn't count, CT 15 still reaches further West than I-95.

I'll try to do both Colorado and Wyoming later, since the surveying errors mean their borders aren't prefectly straight (and even if they were exactly at the intended lines, the Northern and Southern boundaries would still bend sightly due to Earth's shape).

Edit: After a quick search in Google Maps, here is what I've got for the two square states .
Colorado:
N: Where WY 70 dips into Colorado. If that doesn't count, then US 385.
S: US 84
E: CO 116
W: CO 90

Wyoming:
N: US 212 atop the Beartooth
S: US 287
E: US 20 (beating US 26 literally by an inch!)
W: US 191 at the Northwestern corner

And as an extra bonus, here are the extremes for my home region of Aragon, Spain (only national and regional routes are included):
N: A-136 (Surprise, the Portalet pass is sightly more North than the Somport one)
S: A-1514
E: N-230
W: A-2 (almost absolute West)

[hotdogPi]

(and even if they were exactly at the intended lines, the Northern and Southern boundaries would still bend sightly due to Earth's shape).

A line of latitude has no segments that are more north or south than another part of the line, despite the line being curved.

[Eth]

Georgia's are nicely well defined:

North: GA 28 at the NC state line (notice the state line deflects northward at the east end)
East: US 80 about 1.5 miles shy of its end on Tybee Island (it turns slightly west after that)
South: GA 23/121 at the FL state line
West: GA 301's north end at the AL state line

[bassoon1986]

Louisiana:

North: the internet says the northwest-most section is slightly further north despite the northern border of the state being on a parallel. If that's the case, I-49 at the AR state line is the closest highway to the coordinates given.

South: south terminus of LA 3090 in Port Fourchon

West: LA 82 over the Sabine River at the TX border

East: LA 23 before it heads southwest near its terminus in Venice


iPhone

[Jim]

I-95 in CT appears to be the only instance of the same highway being multiple of the most extreme points.

AR 43 is a legitimate contender. I don't feel like going through the entire Arkansas-Missouri border to see if another crossing is barely further north, but it is definitely the westernmost.

TM's data uses two different points for AR 43's clipping of the corner, but those two points are its western and northern extremes within the data.  It finds nothing further north, and it looks like one could make the case for shifting the AR/MO border north by a fraction based on the OSM map on which it's plotted.





Here are the 10 northernmost and westernmost points in Arkansas among those points plotted in TM data.

Code Select Expand

By northernmost:
<BestOf: AR43Sil/MO43@AR/MO  (36.499462,-94.617683) AR279@AR/MO  (36.499434,-94.276161) US71@AR/MO  (36.499339,-94.269487) AR23@AR/MO  (36.499256,-93.709752) AR143@AR/MO  (36.499201,-93.648276) AR43Sil/OK20@OK/AR  (36.499167,-94.61782) AR59/MO59@AR/MO  (36.499132,-94.480319) US63@AR/MO  (36.499063,-91.536777) AR395/MO17@AR/MO  (36.499046,-91.806049) AR221/MO39@AR/MO  (36.498839,-93.560085) AR21/MO13@AR/MO  (36.498822,-93.397479) AR87Eli@AR/MO  (36.498795,-92.13887) AR265Pea@AR/MO  (36.498727,-94.111556) AR37Gat/MO37@AR/MO  (36.498718,-93.931947) AR5/MO5@AR/MO  (36.498632,-92.48291) >
By westernmost:
<BestOf: AR43Sil/OK20@OK/AR  (36.499167,-94.61782) AR43Sil/MO43@AR/MO  (36.499462,-94.617683) AR43Sil@E390&OK20@E0390  (36.452657,-94.610353) AR43_S/OK20_W  (36.421998,-94.60546) AR43/AR72  (36.403901,-94.60194) AR43Sil@StaLineRd  (36.386032,-94.59937) AR12Gen/OK116@OK/AR  (36.278393,-94.582543) AR43/AR102  (36.384663,-94.57917) AR12/AR43  (36.276512,-94.573687) AR72@SchHouRd  (36.419256,-94.568347) AR102@JayRd  (36.384273,-94.565244) US412@OK/AR  (36.176384,-94.565232) AR43Sil@SeqRd  (36.212643,-94.562473) AR102@MouRd  (36.360982,-94.547577) AR43Sil@MtOliSt_S  (36.196078,-94.541045) >


Of course, TM's data is not perfect, and is subject to errors from the map/image sources used and the actual points chosen by the person plotting its routes.

[Jim]

Louisiana:

North: the internet says the northwest-most section is slightly further north despite the northern border of the state being on a parallel. If that's the case, I-49 at the AR state line is the closest highway to the coordinates given.

South: south terminus of LA 3090 in Port Fourchon

West: LA 82 over the Sabine River at the TX border

East: LA 23 before it heads southwest near its terminus in Venice

TM's data agrees with your north, south, and east, but disagrees on the west.