Sometimes it is not about the destination, but the journey.

In just a weird documentary way, I decided to figure out which
Interstate highways I've been on. I'm going to eschew the 3 digit
ones (which are usually local to a city).

 From West to East (on the nominally North-South highways)

I-5, I-15, I-25, I-35, I-55, I-57, I-65, I-75, I-79, I-81, I-83,
I-91, I-93, I-95, I-97, I-99

Missing ones are:

all the Hawaiian ones (H1, H2, H3, H4)
I-17 (Phoenix to Flagstaff)
I-27 (Lubbock to Amarillo)
I-29 (Kansas City to Canada)
I-37 (Texas)
I-39 (Illinois to Wisconsin)
I-43 (Milwaukee to Green Bay)
I-45 (Houston to Dallas)
I-47 (Louisiana)
I-59 (Gulfport, MS to Chattanooga)
I-69 (Indianapolis to Canada)
I-71 (Louisville to Cleveland)
I-77 (Charleston, WV to Cleveland)
I-85 (Petersburg to Winston-Salem)
I-87 (New York to Canada)
I-89 (Vermont to Boston)

 From South to North (on the nominally East-West highways)

I-10, I-20, I-24, I-30, I-40, I-64, I-66, I-68, I-70, I-76, I-78,
I-80, I-84, I-90

Missing ones are:
I-4 (Florida)
I-8 (San Diego to Tucson)
I-12 (Baton Rouge to Mississippi)
I-16 (Savannah to Macon)
I-26 (Charleston, SC to Asheville)
I-44  (St. Louis to Tulsa) *(I've been on it, but not driven it)
I-72 (Illinois)
I-74 (Huntington, WV to Davenport, IA)
I-86 (Erie, PA to Elmira, NY also a short stretch in Idaho)
I-88 (Quad cities, IA to Chicago)
I-94 (northern US)
I-96 (Michigan)

Okay. I've not been on every mile of the ones I've been on. But I
really have driven on all those interstates. Should be interesting
for folks to look up where some of those are.