Longest unclinched roads you've driven both ends of

[clong]

Interstate - I-44 - 647 miles - have driven Wichita Falls to OKC and I-270 to the Eastern end in St Louis (and also a small segment near Springfield, MO)

[therocket]

US-89 (1,252 miles)

I've only done the segment from Flagstaff to Page, the Bryce Canyon-area segment, and the US-2 to Canada segment.

[pderocco]

When I did my Arizona clinch trip last month, I drove the westernmost few miles of US-64, way up near Four Corners. I had driven the eastern end out to Cape Hatteras back in 1991. I didn't realize they were the same road until entering the data into TravelMapping.

[paulthemapguy]

Either I-64, US31, US45, or US51. Probably one of those.

[flan]

I don't believe I have any national-level routes that I've bookended without clinching. Looks like ND 5 wins for me; I've driven the western 140 miles and the eastern 80 miles, but not the middle 110 miles.

[wriddle082]

I-80 and I-90 are both near misses for me.  I lack I-90 at the western end from I-405 to I-5 in Downtown Seattle, and I lack I-80 at the eastern end from I-280 to I-95.  So I think my longest is I-55, which I have from Tangipahoa, LA to the south end at LaPlace, LA, and from Willowbrook, IL to Lake Shore Drive in Chicago, and several long sections in between but not all of it.

For US highways, it's definitely US 50.  I have it from Sacramento to Carson City, and from Fairfax, VA to Ocean City, MD, and all sorts of sections in between.

And for state highways it's probably the mostly-unsigned TN 1, which I have the ends and most of it in between, but I definitely lack a few bits and pieces in West and East Tennessee.

[kphoger]

Probably I-44 for me.

[kurumi]

I-80 for me, having lived close to both ends.

My Dad might claim I-24, on a single roadtrip vacation from FL to western IA long ago. Both ends were open to traffic, and it would have been a simple clinch, but there were some unconstructed portions in KY. I was already the "map guy" in the family (age 9 or so?) and remember apologizing for all the detours along KY 80.

Also, Dad, teasing me when I-24 dipped south into GA to meet I-59: "are you sure we're going the right way?"