Longest Interstate You Haven't Been On

[djsekani]

I seem to be in rare company having put quite a few miles on both I-10 and I-94.

Never been on I-35 though. I don't think I've even crossed it, unless flying over it counts.

[bing101]

Never been to I-90 and I-95.

[Takumi]

I've never been on I-80 or I-90.

[frankenroad]

For me, it's I-29.

[Hot Rod Hootenanny]

Longest interstate for me to skip over is I-25.

[wriddle082]

I-5

Went to the Bay Area last year to work for 3 weeks, drove most of the interstates in the area, but never ventured east towards Sacramento or Stockton to get any part of I-5.

[JKRhodes]

The longest Interstate I've never been on, also happens to be the longest Interstate in the USA: I-90.

[Ben114]

I-80 for me.

[signalman]

I think it's I-30 for me.  I was initially going to say 35, but having clinched 80 I did get a short piece where they run concurrent in Des Moines, IA.

[ctkatz]

I've driven zero miles of I 81.  and looking at the wiki page, I've driven on a significant portion of every interstate longer than 81 individually and duplexes except I 25 for a mile or barely that in denver from the 70 interchange with 25 to get to coors field.

[paulthemapguy]

I have a photo of I-20 shields from Terrell, TX; Tuscaloosa, AL; Atlanta, GA; and Birmingham, AL.  But at no point did I actually drive on any of I-20's carriageways.  Second place goes to I-85

I drove on a bit of I-20 this past January, so I-85 is now my answer 

[7/8]

Longest Interstate: I-10
Longest N-S Interstate: I-5
Longest Interstate I've Never Intersected: Also I-5

Longest US Route: US 60
Longest N-S US Route: US 59
Longest US Route I've Never Intersected: US 95

[thspfc]

I-40, followed by I-10.

[CtrlAltDel]

I’ve gone through and counted all the 2DI responses in this thread that were marked as at least probable, and not distinguishing between western and eastern routes or W and E suffixes, here’s what I get:

As you can see, I-90 is both the longest interstate as well as the one most likely to be untraveled. There is also a general trend of decreasing length, although that does not seem to translate across the even and odd interstates.

Code Select Expand

Route Count Length
I-90 10 3020
I-10 9 2460
I-20 9 1539
I-84 9 1002
I-35 8 1696
I-15 5 1434
I-25 5 1062
I-80 4 2900
I-40 4 2557
I-94 4 1585
I-5 4 1381
I-81 3 855
I-29 3 756
I-76 3 622
I-22 3 202
I-95 2 1919
I-75 2 1786
I-85 2 666
I-59 2 445
I-8 2 348
I-45 2 285
I-49 1 528
I-30 1 367
I-86 1 286
I-88 1 258
I-72 1 179
I-37 1 143

[Gnutella]

That I haven't been on? I-84 (western).

That I haven't driven on? I-25.

[roadman65]

Western segment of I-84

[sprjus4]

It'd have to be I-94 for me.

Been on I-90 in the Cleveland metro, I-80 on the Ohio Turnpike, I-40 in Barstow & between Greensboro and I-95, I-10 in the Los Angeles metro & between Pensacola and Houston, I-70 between I-81 and the Pennsylvania Turnpike, I-95 in many different sections between Miami and New York City, and I-75 in the Atlanta metro.

[roadman65]

You know after thinking about what interstates I have not traveled I just noticed that I have been on part of all the major long ones.  I-5, I-15, I-25, I-35 etc.  and then I-10, I-20, I-40, I-70, I-80, I-90, and I-94 also.

I-8 I have not been on, but I do not think the OP considers that to be a longest interstate.

[bing101]

I-90 and I-95 are freeways I never been on.

[Verlanka]

For me it's I-90.

[Skye]

Not sure exactly which one is longest, but any of the major north-south interstates west of the Mississippi

[hobsini2]

I-5. Never been to Oregon or Washington. And the only place in California I have been to is LAX.

[michravera]

I was curious what mine was. Looked it up, and found out it was I-25. Odd, considering I've been through all three states I-25 is in.

What's yours?

To my knowledge, I have never even crossed I-45, I-55, or I-65 at right angles since their opening as interstates. I may have crossed all of their eventual routes at right angles (or even rode or driven on some of them) in 1976 on my east on I-80/90 and west on I-70 cross country trip with my parents and siblings.

[Konza]

If connecting from I-81 North to I-88 East in Binghamton, New York does not mean I've been on the eastern I-86, then that's the longest one for me.

If not, then I-22.

[StogieGuy7]

Kudos to the OP for this one - it's an intriguing question to ponder.   

After scouring the national map, I would have to say it's probably Interstate 59.  And I was amazed at just how many interstates I have been on (even if just for a bit).  And have driven on myself, versus as a passenger (nearly 100%). 

The only other significant interstates I haven't been on are: I-19, I-27 and I-82.  A couple of the new funky ones aren't on my list either (I-2, I-14). Been on plenty of northern I-69, but not the Texas derivatives (E, W, A, B, W, X, Y, Z, etc.).  None are longer than I-59 though.