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?"

[I-55]

US 35 at 412 miles is the longest I can think of currently.

Longest state route would be IN-124 at 69.6 miles.

Longest interstate doesn't exist for me, if I've been on both ends I've clinched.

[Bickendan]

The only one I can think of is NH 19 in India, catching the north end in Delhi and the east end outside of Kolkata up to Bardhamman.

[ElishaGOtis]

As of a recent trip, and due to the extension of the route, I-57. I'm counting the "unbuilt" sections as part of the continuous route rather than being two independent highways with different termini.

[SEWIGuy]

I-90

I have been two both endpoints, but not the section from Missoula east to the Black Hills. Also between Cleveland and Boston I have only been on a few sporadic sections.

For US Highways, I'm pretty sure its US-41 - I know the southern endpoint isn't well signed. Otherwise it would be US-51.

[sprjus4]

I-10 - I've been on it from Santa Monica to I-5 in the Los Angeles area, then from Comfort, TX to its terminus at I-95 in Jacksonville, FL.

[zzcarp]

For me, I've driven both ends of I-74 in Cincinnati and Davenport but have never traveled the stretch between Urbana and Davenport or Indy and I-275 in Cinci.

For US routes, US 24 must be it. I have a memory of driving the north (east) end in Michigan off of I-75 back maybe 15 years ago, and I've completed the west end here in Colorado multiple times. I have a lot of isolated segments in-between but no clinch.

For my state route, I have to say CO 149. I've been on the US 50 to Lake City segment and the Creede to US 285 segment, but still haven't driven between Creede and Lake City.

[jlam]

The longest I can think of off the top of my head is CA 1. I've clinched most of it from Dana Point to Leggett, including both termini, but I haven't been on it through Lompoc or the Big Sur.