State roads at your state's borders - how many keep the number across the line?

[KCRoadFan]

Looking at the maps of various states, I know that in many instances, neighboring states will coordinate their highway numbering so that a given state highway will retain the same number across the state line - however, on other occasions, the number of the road will change, or sometimes, the road on one side of the line won't even be a numbered road at all.

As far as Missouri (the state where I live) goes, here is a list of state routes that cross into neighboring states, as well as their respective designations across the state line. (Examples of roads that keep the same number across the border are listed in boldface; the ones that used to do so, but no longer do, will appear in italics.)

MO 2 continues into Kansas as K-68.
MO 5 continues into Iowa as IA 5, and into Arkansas as AR 5.
MO 13 continues into Arkansas as AR 21.
MO 15 continues into Iowa as County Road V56 (formerly IA 15).
MO 18 continues into Kansas as a local road (359th Street).
MO 21 continues into Arkansas as AR 115.
MO 27 continues into Iowa as IA 27.
MO 37 continues into Arkansas as AR 37.
MO 39 continues into Arkansas as AR 221.
MO 43 continues into Arkansas as AR 43.
MO 51 continues into Illinois as a local road, connecting to IL 3, and into Arkansas as AR 139.
MO 52 continues into Kansas as K-52.
MO 59 continues into Arkansas as AR 59.
MO 66 continues into Kansas as K-66.
MO 74 continues into Illinois as IL 146.
MO 77 continues into Kentucky (via the ferry) as a local road, connecting to KY 94.
MO 81 continues into Iowa as IA 81.
MO 84 continues into Arkansas as AR 90.
MO 92 continues into Kansas as K-92.
MO 108 continues into Arkansas as AR 77.
MO 126 continues into Kansas as K-126.
MO 148 continues into Iowa as IA 148.
MO 149 continues into Iowa as County Road T30.
MO 150 continues into Kansas as a local road (135th Street, formerly K-150).
MO 171 continues into Kansas as K-171.
MO 202 continues into Iowa as IA 202.

As you can see here, Missouri has 26 state highways that cross the state's borders, and among those, 13 of them retain the same number across the state line - a proportion of exactly 50%. How does your state measure up in that regard? Also, are there some regions of the country where state roads are more likely to keep the same number across state lines? I know that it's very common in New England because a lot of the state road numbers there are holdovers from the erstwhile "New England Interstate Route" system. Anyway, whatever you find regarding your state's highways and how many retain the same number across their borders - I'm interested to hear more!

[jp the roadgeek]

CT-MA

Roads that do: 41, US 7, 183, 8, 189, 10/(US) 202, 168, 187, 75, 159, I-91, US 5, 192, 220, 186, 83, 19, 32, I-84, 198, 169, 131, 197, 12, I-395, 193

Historically, but Sturbridge still thinks it does: 15

CT routes that end at border (SR's not included): 272, (historically: 179)
MA Routes that end (or become SR's) at CT border: 7A, 31

CT-RI

Roads that do: US 1, 78 , 216, I-95, 138, 165, 14, US 6, 101, US 44

There are no roads that end at the border.  CT 14A rejoins its parent a few feet before the border. CT 2 ends at US 1 and RI 117 ends at RI 14 near the border. Historically, CT 184 did cross the border, but now ends at CT 216 near it.

CT-NY

Roads that do: US 1, NY 120A* (CT portion remains a NY Route), I-684 (twice), 123, 137, 116, 35, I-84, US 6/202, 55, 343, US 44

CT Roads that used to but no longer do: 124, 361

CT Roads that do not and never did: 15, 104, 341, 41

NY Roads that do not: 433, numerous county routes

[LilianaUwU]

Québec is a little bit different with their unique system, but I'll play this game anyways.

QC-ON

Routes that keep their number: 148
Routes that don't: 5, 20, 40, 101, 117, 301, 338, 388

QC-NY

Routes that keep their number: none
Routes that don't: 15, 132, 138, 203, 209, 219, 221, 223

QC-VT

Routes that keep their number: 139, 141, 147, 225, 235, 243, 253
Routes that don't: 55, 133, 143, 237

QC-NH

Routes that keep their number: none
Routes that don't: 257

QC-ME

Routes that keep their number: none
Routes that don't: 161, 173

QC-NB

Routes that keep their number: none
Routes that don't: 85, 289

QC-NL

Routes that keep their number: none
Routes that don't: 138, 389

[Techknow]

CA-OR
CA 161 straddles the state border according to GMaps

CA-NV
CA 28
CA 88
CA 266

CA-AZ
None!

CA-Mexico
None!

[Great Lakes Roads]

Indiana fails in this department lmao

IN-IL
IN 2- IL 17
IN 10- IL 114
IN 18- County Road 880 N
IN 26- IL 9
IN 28- IL 119
IN 32- County Road 1360 N
IN 234- Mill Road
IN 163- Clinton Road
IN 154- W Clover Street
IN 441- ?
IN 64- IL 15
IN 62- IL 141
None continues across the IL-IN state line

IN-KY
IN 161- KY 2262
IN 237- KY 69
IN 135- KY 79
IN 101- KY 1039
None continues across the KY-IN state line

IN-OH
IN 252- OH 126/129
IN 44- OH 725
IN 227- OH 177
"Old" IN 122- OH 122
IN/OH 121
IN 28- OH 571
IN 32- OH 47
IN 26- OH 119
IN 67- OH 29
IN 218- OH 707
IN 124- OH 81
Paulding Road- OH 500
Dawkins Road- OH 613
Woodburn Road- OH 111
IN 37- OH 2
IN 8- OH 18
CR 40- OH 249
IN 427- OH 34
1 continues across the IN-OH state line (IN/OH 121)

IN-MI
IN 120- W Territorial Road
IN 327- Rierson Road
IN 9- M-66
IN 15- M-103
CR 17- M-217
IN 19- "Old" M-205 (Cassopolis Street)
IN 23- M-62
IN 933- M-51
IN 39- M-239
None continues across the MI-IN state line

[roadman65]

The FL-GA line has only two that keep.  FL 15 and FL 121 that both become GA 15 and GA 121 respectively. The rest end at the border.

Don't think AL-FL have any MSR.

[Ted$8roadFan]

In MA-RI, it appears that all routes keep their numbers across state lines with the sole exception of RI-100 in Burrillville that ends at the state line with Douglas, MA.

[thspfc]

WI-83, WI-78, and WI-35 at the IL border. WI-16, WI-243, and WI-70 at the MN border.

[MATraveler128]

MA 1A, 286, 150, 108, 125, 97, 28, 38, 3A, 111, 13, 31, 119, 12, 32, 78, 10, and 63 all keep their numbers into New Hampshire.

[1995hoo]

Various secondary routes that keep their numbers omitted.

VA-/NC-8
WV-/VA-/NC-16
VA-/NC-32
VA-/NC-35
VA-/NC-46
VA-/NC-49
VA-/NC-62
VA-/NC-86
VA-/NC-87
VA-/NC-89
VA-/NC-93
VA-/NC-96
VA-/NC-103
VA-/NC-119
VA-/NC-168
VA-/NC-186

VA-/KY-80

VA-/WV-9
VA-/WV-39
VA-/WV-55
VA-/WV-83
VA-/WV-84
VA-/WV-102
VA-/WV-127 (straddles state line for a short distance)
VA-/WV-259
VA-/WV-311
VA-/WV-598

[GaryV]

Michigan - none

[JayhawkCO]

CO/WY
CO13 continues into WY as WYO789
CO125 continues into WY as WYO230
CO127 continues into WY as WYO230
**Bonus** WYO70 continues into WY as WYO70 (Not counting in totals)

0/3

CO/NE
CO71 continues into NE as NE71
CO113 continues into NE as NE19
CO11 continues into NE as NE27
CO23 continues into NE as NE23

2/4

CO/KS
CO96 continues into KS as K-96
CO116 continues into KS as County Road 12

1/2

CO/OK
None

CO/NM
CO389 continues into NM as NM551
CO159 continues into NM as NM522
CO17 continues into NM as NM17
CO172 continues into NM as NE511
CO140 continues into NM as NM170

1/5

CO/AZ (for the Four Corners haters)
None

CO/UT
CO41 continues into UT as UT162
CO90 continues into UT as UT46
CO318 continues into UT as Browns Park Road

0/3

Total: 4/17 for 23.5%

[wriddle082]

I think nearly all state routes leaving SC going into NC keep their number, and maybe half going into GA keep their number.

I think nearly all state routes leaving NC going into VA keep their number, and a couple of them going into GA keep their number.  None of them going into TN keeps its number.

And I'm pretty sure nothing leaving TN going into any bordering state keeps its number.  And the only places I see a number being kept in KY is 80 going into both VA and across the Mississippi River ferry into MO.

[NWI_Irish96]

Indiana fails in this department lmao

IN-OH
"Old" IN 122- OH 122
IN/OH 121


IN-MI
IN 120- W Territorial Road

So in addition to the one that currently exists, there are two that previously existed. You noted that there used to be an IN 122 that connected to OH 122 near Boston. Also, Territorial Rd/Morenci Rd used to be M-120, which connected to IN 120 near Fremont and OH 120 near Morenci to make a three-state route.

[hbelkins]

I think nearly all state routes leaving SC going into NC keep their number, and maybe half going into GA keep their number.

I think nearly all state routes leaving NC going into VA keep their number, and a couple of them going into GA keep their number.  None of them going into TN keeps its number.

And I'm pretty sure nothing leaving TN going into any bordering state keeps its number.  And the only places I see a number being kept in KY is 80 going into both VA and across the Mississippi River ferry into MO.

You and 1995hoo both missed KY 160, which runs between Cumberland/Benham/Lynch and Appalachia and crosses Black Mountain, Kentucky's highest point.

I suspect it (and KY/VA 80) are Virginia's doing, as Kentucky generally doesn't continue route numbers from other states. Granted, the river borders limit the number of crossings of state routes, but there are ample opportunities for continuation with Tennessee. There are a few state-numbered Kentucky routes that become county routes once they cross into the Volunteer state.

Virginia is pretty good about the continuation, but doesn't play well with Tennessee. The only continued route number I can think of between the two states is 70. TN 93 becomes VA 224 (and is a great route from the east side of Kingsport to join US 23) and TN 44 becomes VA 75 southeast of Abingdon.

[Bitmapped]

I suspect it (and KY/VA 80) are Virginia's doing, as Kentucky generally doesn't continue route numbers from other states. Granted, the river borders limit the number of crossings of state routes, but there are ample opportunities for continuation with Tennessee. There are a few state-numbered Kentucky routes that become county routes once they cross into the Volunteer state.

Virginia is pretty good about the continuation, but doesn't play well with Tennessee. The only continued route number I can think of between the two states is 70. TN 93 becomes VA 224 (and is a great route from the east side of Kingsport to join US 23) and TN 44 becomes VA 75 southeast of Abingdon.

VA/TN 91 also keeps its number.

Virginia made a concerted effort about 1940 to renumber routes to sync up route numbers with those in adjacent states. In some cases, this involved both states renumbering their routes, like with WV 16 and WV 39.

[Dirt Roads]

WV-/VA-/NC-16

VA-/WV-9
VA-/WV-39
VA-/WV-55
VA-/WV-83
VA-/WV-84
VA-/WV-102
VA-/WV-127 (straddles state line for a short distance)
VA-/WV-259
VA-/WV-311
VA-/WV-598

For the rest of West Virginia, simply add:

WV/OH-527
WV/PA-43

Also, there are a few secondaries to add:

WV-635/SR-635 (Buchanan County, Virginia)
(West Virginia) LSR-857*/PA-857

Plus a few oddities:

WV-618 almost connects with OH-618.
WV-7 almost intersects with OH-7, but that route runs perpendicular.

*LSR-857 in Monongalia County is the only LSR route that is only in one county.  If I my suspicions are correct, the designation LSR is supposed to mean "long secondary route" where the number stays the same between counties.  The other two that I know of are LSR-21 (former US-21) in Kanawha, Jackson and Wood counties; and LSR-73 (former WV-73) in Marion and Monongalia counties.

[1995hoo]

I didn't list VA-/TN-70 and -91 because I understood Tennessee's routes of those numbers to be secondary routes and I wasn't listing secondary routes.

[Mapmikey]

For Virginia there is also:

SR 903/NC 903
Former SR 615/NC 615

Virginia thought Tennessee was renumbering TN 44 to TN 75 which is why they renumbered VA 77 to VA 75.

Virginia also used to have VA 17/MD 17 but they rerouted VA 17 to Winchester not all that long after.

There also was VA 59/WV 59 in the post-1940 era.

VA 80 did not reach Kentucky until 1950 and was extended there at Kentucky's request to meet their new highway.

[wriddle082]

I didn't list VA-/TN-70 and -91 because I understood Tennessee's routes of those numbers to be secondary routes and I wasn't listing secondary routes.

TN "secondary"  routes are more formalities than anything else.  Primary routes in TN "primarily connect cities" , whereas secondary routes may not be the highest quality route between two given points.  Otherwise, they are the same, despite the different shields, and many routes switch between primary and secondary multiple times.

And yeah I did forget that VA tries to play nice with other states, but TN definitely doesn't play nice with NC, GA, AL, MS, or KY.

[US 89]

Utah is 1 for 15, but historically had another. Starting at the northwest corner and going clockwise:

Idaho:
- SR 42 becomes old SH 81/CR 30S
- SR 23 becomes old SH 35/CR D1
- SR 200 becomes old SH 34/State St

Wyoming:
- SR 30 becomes WYO 89
- SR 16 becomes WYO 89 (same route, because 16 and 30 are supposed to be an implied connection)
- SR 150 becomes WYO 150
- SR 43 becomes WYO 414
- SR 43 becomes WYO 530

Colorado:
- Browns Park Rd/FA 1364 becomes SH 318
- SR 46 becomes SH 90
- SR 162 becomes SH 41

Arizona:
- SR 59 becomes SR 389

Nevada:
- SR 56 becomes SR 319
- SR 21 becomes SR 487
- SR 58/BL-80 becomes old SR 224/BL-80
- SR 30 becomes SR 233, which was numbered 30 before Nevada renumbered basically everything in 1978

[wanderer2575]

Michigan - none

M-49 and OH-49

Potential could-have-beens had the number not already been used in Michigan:
  *  IN Elkhart County 17 and M-217
  *  IN-39 and M-239

[froggie]

For Vermont, most do.  It's shorter to list the exceptions:

- The aforementioned Quebec routes.
- VT 105A/Unnumbered Quebec road
- VT 17/NY 185
- VT 31/Washington CR 25)
- VT 279/Unsigned NY 915G
- VT 113/Unnumbered New Hampshire road
- VT 105/Unnumbered New Hampshire road (but was technically signed as "VT 105" at one point)
- VT 114/Unnumbered New Hampshire road

I'm not counting the Lake Champlain ferries, since the ferry landings are not part of either state's system.

Worth noting that when Quebec did their great renumbering, Vermont renumbered most of the state routes in its side of the border to match.  The only exception was VT 108.

Not counting VT 100 or NH 103 since, in both cases, they are concurrent with other routes that do keep their number crossing the state line (8 and 12 respectively).

[zzcarp]

Québec is a little bit different with their unique system, but I'll play this game anyways.

QC-ON

Routes that keep their number: 148
Routes that don't: 5, 20, 40, 101, 117, 301, 338, 388

QC-NY

Routes that keep their number: none
Routes that don't: 15, 132, 138, 203, 209, 219, 221, 223

QC-VT

Routes that keep their number: 139, 141, 147, 225, 235, 243, 253
Routes that don't: 55, 133, 143, 237

QC-NH

Routes that keep their number: none
Routes that don't: 257

QC-ME

Routes that keep their number: none
Routes that don't: 161, 173

QC-NB

Routes that keep their number: none
Routes that don't: 85, 289

QC-NL

Routes that keep their number: none
Routes that don't: 138, 389

I'm not sure when or why Quebec renumbered all of its routes, but it used to have several route numbers continue from its neighbors (1955 Shell Map referenced).

ON-QC: ON 17-QC 17, ON 2-QC 2
NY-QC: US 9-QC 9
VT-QC: US 7-QC 7, US 5-QC 5
NB-QC: QC 2 - NB 2

Notice that Highway 2 was once continuous through 4 provinces from Windsor, Ontario to Halifax, Nova Scotia.

[Road Hog]

Several numbered highways in Arkansas continue as lettered routes in Missouri as well.