If you are driving in downtown San Antonio, there is an intersection where the big green highway signs tell you you can go this way down I-35 to get to Austin (80 miles), this way down I-37 to get to Corpus Christi (144 miles), or this way down I-10 to get to El Paso which is 550 miles or an 8 to 9 hour drive away. Your Google app says, “Take Exit 156 to I-10 El Paso.” Other than joke signs, what is the farthest city on a highway exit sign that you have seen?
I passed by a sign in Barstow California that said LAS VEGAS 180 MILES, SALT LAKE CITY 575 MILES
When travelling north along I-5 from San Diego to Olympia when I moved here 20 years ago, I first saw a sign for Portland somewhere around Sacramento. The distance was somewhere in the 700 mile range.
These are no joke.
Probably more extreme examples out there:
Helps to refuel regularly.
Both sides of US 50 has a sign saying it’s 3073 miles to Ocean City/Sacramento.
And here’s one near Baltimore on I-70 saying Denver is 1700 and Cove Fort is 2200.
I was going to post this one. I lived near it for the first 55 years of my life, and after driving on the eastern end of I-70 for decades, in 2018 my wife and I drove the western end for the first and only time when we were moving back east after living in Las Vegas for five years. (Unfortunately, we weren’t able to drive the entire length of the highway.)
Holy cow! That’s amazing!
I’m from Massachusetts originally and, out east, distances are very truncated, especially in New England. Pittsfield to Boston, a trip across the entire width of MA, is only 137 miles. That’s “long” for us.
Pittsfield to Provincetown is more like 240 miles. But, yeah.
Route 20 in Kenmore Square in Boston:
Its twin is in Oregon:
Not sure if you can get much longer than that in the US.
Yeah, that beats the one for Denver that I’ve seen on I-70 heading west out of Topeka, which is 510 miles IIRC.
In southern NY state going north in I-87 where the name changes from The Major Deegan Expressway when to The NY State Thruway crossing from the Bronx into Westchester County. Within a mile or so north of that point I remember a sign with about 3 cities distant, and one of them was Buffalo at about 420 miles.
I’m thinking “Pan American Highway”…
I believe that this is the longest highway in the US, so you won’t find a longer highway exit/distance sign. However, there are cities between Boston and Newport, Oregon that they decided to skip that would be a little bit closer (Worcester, Springfield, Albany, Chicago). It’s not like it is a vaste wasteland between Boston and Oregon! 
Wanna bet? 
The one I see all the time was in Post #2.
Sign in Copper Harbor, MI (nearstrong text the end of US 42)
Eagle Harbor (ahead)
Houghton (left)
Miami Fla 1990
I know in Bishop, CA there is a sign for the other end of US 6
(click on broken pic – Provincetown 3205)
Brian
Seen it. Walked it. Road sign at Roncesvalles for Santiago de Compostela.
I don’t think these fit the OP’s definition of an exit sign but are rather furthest away you’ve seen a control city. Correct me if I’m wrong @Mesquite-oh but you are looking for a sign like “Bupkis Exit 102” and that’s 130 miles away. Right?
I was just thinking about having seen the Sacramento end of this, but couldn’t remember if it was I-80 or US-50, so thanks for the article.
In the mid-1960s, there was a sign on US 40 in Atlantic City that listed the 3000+ mileage to San Francisco.
Several websites I looked at say that Interstate 90, Boston to Seattle, is the longest in the US (3101 miles). Anyone have any signs from that?
Edit: Oops, looks like U.S. Route 20, already mentioned, beats it.