My rule is “breathing the air at ground level”. So drive-throughs and airport visits count. But I’ve never driven through a state where I haven’t gotten out of the car at least once.
My total is 40.
The only state I’ve driven through without getting out of the car is Arkansas, once. Unfortunately I did technically “stop” because there was a lot of construction.
Alabama may count but I don’t remember if my family visited there when growing up. Mississippi almost counts but I think there is a rest stop along I-10 I’ve been to a couple of times. I’ve only been out of the car once in Idaho but that was to sleep in a motel. I still don’t count it as having “been” there since I was just on my way to Yellowstone.
Other states I’ve driven through but not visited: Kansas, Missouri, Nebraska, and technically Iowa since I took I-29 in a futile attempt to save time in getting to Salt Lake City. I thought that the traffic would be much less than on I-80 than on I-70 especially through Denver (not to mention the mountains.)
I didn’t count on it being the week of Sturgis, with loads of motorcycles and haulers fastidiously obeying the speed limit in both lanes.
A followon question to that (as several people said similar):
What states can you drive through without HAVING to stop at least briefly for gas?
I think it would be impossible with any of the Western states - ruling out brief state-line crossing such as this one.
I’ve made no-stop crossings through West Virginia (I-81, total distance 20ish miles), Maryland (I-81, also US 15), Delaware, New York (around the NYC area crossing from NJ into CT), and New Hampshire. Washington DC as well though that hardly counts. I could see it being possible in Rhode Island though I’ve never done so. Massachusetts might just be doable - looks like a 2ish hour drive north to south. DItto New Jersey if the traffic is unusually good.
In the south, it looks like the Mississippi and Alabama coastal panhandles could be crossed w/o needing to stop.
I can’t think of any others offhand unless you’re in a car equipped with a HUGE gas tank, and wearing Depends 
Oh yeah: the list of states I have never been to is relatively short:
- Alabama
- Mississippi
- Louisiana
- Michigan
- North Dakota
- South Dakota
- Minnesota
- Nebraska
- Alaska
- Iowa, which I could claim, except we didn’t stop: we crossed the Mississippi River when we were leaving a wedding in western Illinois, just to say we’d done so; we looped around one town close to the river and took a slightly different route to get back on track for our drive home to North Carolina…
Vermont would also be doable, and any state no matter how large if you’re doing a corner.
What kind of mileage do you get? I’ve routinely driven from Philadelphia to Boston on a single tank of gas - about 300 miles. And that was with a crappy 1980s Volare. My current car can go at least 500 miles highway without a fill up.
47 states I have collected. The only three remaining are Oklahoma, New Mexico, and Hawaii.
My criteria is my foot must touch non-airport ground.
I forgot about that corner of Arizona. Almost makes me want to change my answer.
One time when I chnages planes in Salt lake City the plane I was getting off/on (I don’t remember) was small enough that we didn’t use a jetway, but stairs. We walked on the tarmac. At teh time I counted Utah since I was outside (don’t think I would have counted had I used the jetway and stayed inside). I’ve since been to Utah more legitinmately (camped in Zion, hiked there and in Snow Canyon parks)
I have driven though Indiana on the way to Michigan from Wisconsin. Pretty sure I have got out of my car while in teh state so I am counting it.
Brian
Been there - has the peed discussion
done that - Delaware specific
Boots on the ground. Auto pass-throughs, airports and such don’t count. usually I also have to buy something in the state for me to count it.
That really sounds like a fun way to see a lot of out of the way places. Thinking about it, it is highly possibly that there are counties in South Carolina I have not been to, and I’ve lived here almost all my life. Almost certainly there are a few in the Upstate, like, uh. Union? Would I ever have been to Union County? Or Oconee? Now I’m thinking about class trips when I was a kid, what the hell is in Union?
With airports, 28 states. Without, 27. That’s in less than 10 weeks total time over The Pond and some of that was spent in Canada. Stayed overnight at 18.
Not bad for a Brit…
Good criteria, that.
I recently got ND, MT, and ID taken care of.
That leaves WY, HI, SD, NE.
Even if I had included walking thru airports as a criteria, my list of states wouldn’t change. 
I’ve been to all 50 states but have only driven through North and South Carolina (I think). I honestly don’t remember if we stopped in either state; it was a family vacation when I was a teenager over 40 years ago.
We were driving back to Wisconsin after visiting my grandparents in Florida. My dad, an avid golfer, wanted to visit Augusta GA. We then drove to Knoxville TN to visit one of his navy buddies, taking us through NC and SC. We probably stopped in one of them, it’s almost 300 miles from Augusta to Knoxville. I can’t say for sure, though. I’ve always wanted to go back for a real visit.
I know I at least got out of the car in the other 48; spent time and did things in most of them.
I’ve been to 45 by ‘at least changed planes’, 44 if you have to leave the airport (stopovers in Anchorage in the old days of flights to Far East). I don’t see much rationale in differentiating beyond ‘have driven through’.
Yeah, true. We can go 300+ miles on a tank in either of our current cars, and that’s enough to let us skip some states (en route to Florida).
We still have to stop for a bathroom break in each state - multiple times per state if my husband is along - the man has a bladder the size of a thimble, where I was apparently a camel in a former life.
If I set foot in the state then I’ve been there. I don’t know for sure what states I’ve flown over.
By that standard, I’ve never even been to my own home state!
Am I being whooshed, or are we expected to believe this??