Short, but Important

[webny99]

A few more short, important roads for the military ...

I-781 in New York (Fort Drum)?

Yes, and indeed there was already some discussion of I-781 earlier in the thread:

The first one that came to mind was I-781. It's an important 4-mile connector between I-81 and Fort Drum, but arguably more importantly to the US 11 corridor and much of the North Country region, including Gouverneur, Canton, and Potsdam. Before I-781 was built, NY 342 served that movement, and it was one of the busiest two-lane roads in the state.

I-781 was only built because Fort Drum would have closed without it.  DOD demanded it.

From what I've heard, NY 342 was in fact the busiest two-lane road in the whole state before I-781 opened.

[mgk920]

A few more short, important roads for the military

I-564 into Norfolk Naval Station, VA
All-American Freeway to Fort Bragg (that NC has not designated this an interstate yet is mind-boggling)
IL 158 to access Scott AFB, IL
BL I-44 to Fort Leonard Wood, MO
TX 601 to access Fort Bliss, TX including Biggs Field

I-781 in New York (Fort Drum)?

I-H3 also.

I believe that I-H3 is too long for the OP's criteria.

Mike