Wheat Thins are my go to snack. No crumbs and they are very satisfying.
I usually go for cheese, beef jerky, nuts, and fruit like grapes or bananas.
Avoid junk food, alternate caffeinated beverages with and equal amount of water.
I’m also getting old enough that “pee early, pee often” is starting to apply.
Basically, I stop every 90 minutes or 100 miles for a potty break and a quick snack.
As a general rule, 10-12 hours and I’m a bit toasty as a soloist, any longer than that and I have to overnight somewhere. Be sure to carry the means to rent a room for the night, just in case. That’s a hella long drive you’re planning there, fatigue can be deadly, and delays happen.
A box of cheez-it crackers accompanied by a Thermos full of ice cold milk always works for me. A can of nuts would be easy to eat too.
Dunkin Donuts munchkins are easy to eat.
M&M’s are one handed food.
I like the idea of Subway.
Cherry or grape tomatoes would work.
A bag of sliders from White Castle would work as long as you ste them right away.
Malted milk balls (Whoppers) are easy to eat.
Pop tarts as long as you aren’t a pig who eats with his mouth open.
Make up some ham roll ups with cream cheese spread on the ham and roll it arpund a pickle could be one handed food.
Grapes or sliced fruit would work.
I suppose you could do yogurt and use a straw to suck it up - don’t know if it would work cause I hate yogurt but some kid in a tv commercial does it when his sister hides all the spoons…
Have a safe trip, by the way! 
PS - forgot to add Hostess ho-ho’s. Can’t make a mess with those.
Most snack ideas were great. Please don’t drive without getting out and walking once in a while. Fast food restrooms/a deli/ a truckstop. 17 hours straight?
Bag of almonds.
Jim,
This is slightly O/T for the food suggestions (but they’ve got you covered), but some advice from a frequent I-80 traveler. Be aware that heading West on I-80, you should gas up and use the facilities no later than Lincoln, NE, because from there clear on into I-76 heading south into D, there is precious little available in terms of both gas and facilities. The few there are know this and charge exorbitantly.
a shake with a straw
A whole roasted turkey. Just put it in the cooler and go. As you drive, you can reach into the cooler with your free hand and pull off chunks of that bad boy. I probably wouldn’t go with stuffing, but YMMV.
I’m a fan of Uncrustables, and I have a 5-hour drive coming up on Saturday: I plan to take a couple out of the freezer before I leave, and have them for lunch in the car. They’re not messy, and can be eaten with one hand. (I guess I’ll find out whether they can be unwrapped with one hand… ;))
No, theoretically 14 hours straight, but I added 3 for rest stops, food, gas etc.
Not suggested yet… (I think)
Baby carrots
Peeled hard-boiled eggs
Cheese strings
Yogurt tubes
Rice cakes
A can of peanuts – light- or non-salted. If it’s small enough it may even fit in a cup holder so you don’t have to fiddle with opening it, and you can dump a load of peanuts directly into mouth.
Cold pizza. Just ziploc the slices and store them in the cooler. Pepperoni, sausage, veggie; whatever, the cheese holds it all together.
Eat? In the car? Not a chance.
I travel a desolate stretch of Texas several times a year (Concho, Tom Green, Howard, Sterling, Glasscock, & Dawson Counties) I keep black coffee and/or diet coke on hand, but that’s it.
I nibble to stay awake. Sunflower seeds are perfect for this. I spit the shells into an empty coffee cup.
No way, man. You lose a piece of that chocolate covering on your shirt or on your pants, you are fucked for the rest of the trip! 
GORP and the new Cheezit- whole grain.
I remember Tiger Woods saying he drove, overnight, halfway across the country to be with family on 9/11. He said he snacked on protein bars and energy drinks all the way.
Or you could always just eat the fastest food, although it is a bit crumbly:
A scone - (sounds like gone in Brit Eng)
I’ve tried that and got a pound and a half of granola crumbs down my cleavage.
Chicken McNuggets. I suggest the 20 piece box.