Routes you've used in 2 bordering states but never crossed the state line on it

[SkyPesos]

EDIT: Thread used to be for 2di only; it's open to 3di and US routes as well now. Feel free to exclude US routes from your list if it takes too long to gather info.

Thought of this thread idea after listing the states I've been on/clinched for each 2di and that a lot of them have an untraveled section in two neighboring states even though it may not seem like it from just listing states. Which 2di have you been on in both neighboring states on a route, but have never crossed the state line on it?

For me, 2di:
24: KY/TN - missing segment between I-69 and I-65
64: KY/WV - missing segment between I-75 and US 35
65: KY/IN - missing segment between I-64/71 and I-465/74
69: IN/MI- missing segment between IN 58 and I-94 Pt Huron
77: WV/OH - missing segment between I-64 and US 30
80: IN/OH - missing segment between I-65 and I-76
90: IN/OH - missing segment between I-65 and I-71, NY/MA - missing segment between I-190 and I-84
94: WI/IL - missing segment between the two I-90 interchanges, IN/MI - missing segment between I-65 and I-75

[Dirt Roads]

Did I say eclectic?  This thread hits the nail on the head...

I-10 between California and Arizona
I-20 between Georgia and South Carolina
(Triple whammy) I-24 between Illinois and Kentucky, I-24 between Kentucky and Tennessee and I-24 between Tennessee and Georgia (first time, but not the second time)
I-65 between Kentucky and Indiana
I-80 between Ohio and Pennsylvania
I-81 between Pennsylvania and New York
I-90 between Ohio and Pennsylvania
(Been there, but before it was posted) I-95 between Pennsylvania and New Jersey

[webny99]

Let's see...

I-64 VA<>WV
I-70 MD<>PA
I-75 MI<>OH
I-77 OH<>WV
I-80 OH<>PA
I-94 IL<>WI
I-95 NJ<>PA
I-99 NY<>PA (not currently possible, of course)

I-84 is an interesting case... I have been on disconnected segments in NY/PA and MA, but it does not cross the NY/MA line, so it doesn't count. Same with I-94 not crossing the water border between IL and MI.

[thspfc]

I-94 WI and IL
I-35 IA and MN

US-6 IA and NE
US-6 NE and CO
US-10 WI and MN
US-12 WI and IL
US-12 WI and MN
US-20 IL and IA
US-30 IA and NE
US-34 NE and CO
US-41 WI and IL
US-51 WI and IL
US-52 IA and MN

Probably some I missed

[webny99]

I-84 is an interesting case... I have been on disconnected segments in NY/PA and MA, but it does not cross the NY/MA line, so it doesn't count. Same with I-94 not crossing the water border between IL and MI.

I would add to this a general note of caution for routes with segments in two bordering states that do not cross directly from one state to the other. I almost messed up with I-70, because it doesn't go directly from PA to OH (which do share a border, obviously), but instead goes through WV. So PA<>OH is not a valid answer for I-70; you would need to have traveled on I-70 in WV without crossing the state line; in which case the WV<>OH and WV<>PA borders would be what you would count.

An even more technical example would be I-95, where MD<>VA is not valid because of the 0.08 mile segment that clips the corner of DC. And of course there's no way to travel the DC segment without entering both MD and VA, so barring some extreme creativity, DC<>MD and DC<>VA aren't viable answers either.

[US 89]

I-26, NC/SC
I-29, IA/SD
I-30, TX/AR
I-35, TX/OK
I-35, OK/KS
I-40, AZ/NM
I-40, NM/TX
I-40, TN/NC
I-44, OK/MO
I-55, AR/MO
I-65, TN/KY
I-69, (TN)/KY
I-95, SC/NC

[jp the roadgeek]

I-95 in PA and NJ (though I did cross it on the old route)

[webny99]

I-95 in PA and NJ (though I did cross it on the old route)

94 WI and IL

My guess is these are going to be the two most common answers, the first one for the reason mentioned, and the second because the I-90/I-94 situation seems custom-made for this thread: I-94 literally leaves I-90 and crosses the state line, only to rejoin it less than 150 miles later.

[TheHighwayMan3561]

Apparently I have a lot of cleanup to do in Missouri...

I-20 TX/LA
I-29 IA/MO, SD/IA, and ND/SD
I-40 OK/AR
I-44 MO/OK
I-55 MO/IL
I-64 MO/IL
I-70 IL/IN

[plain]

I-20 AL-GA
I-74 IN-OH

[7/8]

All my interstate travels are here: https://travelmapping.net/user/system.php?units=km&u=7_8&sys=usai

25: CO/WY
29: ND/SD
35: IA/MN
40: NC/TN
65: IN/KY
70: IL/MO
70: OH/PA (EDIT: Doesn't apply)
71: KY/OH
74: IL/IN, IN/OH
75: GA/KY, KY/OH
80: OH/PA
90: IL/IN
94: IL/WI
95: DE/MD
99: NY/PA (a strange case where the designation ends at the state line)

[wriddle082]

I-20 LA/TX
I-49 LA/AR
I-55 LA/MS
I-70 CO/KS, IL/IN, IN/OH, and PA/MD
I-76 OH/PA
I-80 PA/NJ
I-90 NY/PA, IL/IN
I-91 MA/VT
I-94 WI/IL, IN/MI
I-95 NY/CT, CT/RI, and RI/MA

[webny99]

70: OH/PA

See my note of caution in reply #4... almost did the same thing myself but I-70 actually goes through WV between OH and PA.

[Rothman]

I-5: OR/CA
I-10: AZ/NM
I-24: TN/KY
I-25: CO/NM
I-26: NC/SC
I-35: MN/IA, IA/MO, KS/OK, OK/TX
I-40: TN/NC
I-55: MO/AR
I-65: AL/TN
I-69: IN/MI
I-80: CA/NV
I-85: AL/GA
I-90: WY/MT

[Techknow]

I-90: IL/WI

How did this happen? I been on I-90 from the O'Hare airport to Chicago, and then in a separate trip two months later that year shunpiked from the airport to Madison, WI, so I eventually drove on I-90 there. When I came back to the airport, I drove through the state line on I-94/I-41

[MATraveler128]

I-91 MA/VT and MA/CT

Edit: I forgot one more. I-81 in New York in Binghamton and I-81 in Pennsylvania from I-84/380 to PA 309.

[Scott5114]

49: AR↮MO (the Bella Vista Bypass didn't exist last time I was in the area
55: AR↮MO (only been on it in these two states in the St. Louis and Memphis areas)
80: NE↮IA↮IL (did a fairly substantial stretch in Central Nebraska, the I-35 concurrency in Des Moines, and then some in the Chicagoland area)

[GaryV]

Must the 2di have a border crossing between the 2 states to qualify?  Because I've been on I-94 in Michigan and Wisconsin, but never crossed the border on it.   

[NWI_Irish96]

2di
10: CA/AZ
20: AL/GA/SC
55: MO/AR/TN
80: UT/WY
90: WY/SD
95: RI/MA

3di
None

us (* indicates one or both states only due to interstate concurrency)
1: NY/CT, MA/ME
6: RI/MA*
14: WI/MN*
16: MT/SD*
22: OH/PA*, PA/NJ*
24: MO/IL*
25: TN/KY*
29: DC/MD
30: OH/PA*
40: CO/KS*, MD/DE*
41: FL/GA*, GA/TN*, TN/KY*
42: KY/OH
50: MO/IL*, OH/WV
52: MN/IA*, OH/WV*, VA/NC*
60: KY/WV*
61: AR/MO*, MO/IA*
63: AR/MO*
64: AR/TN*
67: TN/AR*, AR/MO*
70: AR/TN*
77: TX/OK*
80: MS/AL*
83: SD/ND*
95: CA/NV*
151: IA/WI
219: MD/PA*
220: VA/WV*
287: TX/CO*

[NWI_Irish96]

Must the 2di have a border crossing between the 2 states to qualify?  Because I've been on I-94 in Michigan and Wisconsin, but never crossed the border on it.   

If you take the OP literally those would count, but since they're trivial I'd say no. I'd also have that crossing plus I-95 between Delaware and New Jersey. Probably a few others I haven't thought of.

[ilpt4u]

I may edit this as I think about it more, but off the top of my head, only coming up with one two:

I-10 Cali/AZ
I-75 Ohio/Michigan

[1995hoo]

Interesting idea for a thread.

I-25: CO/NM
I-26: SC/NC
I-40: TN/NC
I-55: AR/MO
I-65: AL/TN, TN/KY
I-70: MO/IL, IN/OH (#$&* wreck on the highway prompted a detour), OH/WV (took I-470 and I wish I'd opted for I-70)
I-75: GA/TN, TN/KY, KY/OH, OH/MI
I-77: WV/VA
I-80: OH/PA, PA/NJ
I-90: OH/PA, NY/MA
I-93: MA/NH

Honorable mentions: I've crossed the TN/GA state line on I-24 east of I-59, but never on the portion west of I-59. I've also crossed the NJ/PA state line on what is now I-95, but it wasn't designated as I-95 at the time (and I also crossed more than once on the old routing).

[7/8]

70: OH/PA

See my note of caution in reply #4... almost did the same thing myself but I-70 actually goes through WV between OH and PA.

I even read that post, but I guess I was too tired to notice my own mistake.

[Mapmikey]

I-5 CA/OR
I-55 MS/TN and AR/MO
I-70 KS/MO
I-75 TN/KY/OH/MI
I-90 WY/SD
I-95 CT/RI

[SEWIGuy]

5: CA/OR
10: AZ/CA, TX/LA
35: IA/MN
40: TN/NC
69: IN/MI
75: AL/FL
85: AL/GA
90: SD/MT, NY/MA