there's lots of places with mile markers under 400.
455 is notable ( not just because it's the largest of the Buick big blocks ) because there are so few states where you can achieve that.
there's almost a 455 in Nebraska on I-80 ... but it's clear over in Omaha next to the Iowa border. and you actually only get 454.
Montana has one on I-90 on the east side of Billings.
Cali has one on I-5.
Texas has a couple, i'm sure Alaska does as well.
Tennessee isn't wide enough. neither is Pennsylvania or New York. nope, not Florida either. i'm pretty sure you're not going to find a 455mm east of the Mississippi.
i was just shocked to find a 455 in Idaho ... and on an "east/west" road no less. in fact, wiki says that there are only 415 miles on US 30 in Idaho. but who are we to argue with the Idaho DOT?
maybe there's a Buick / Olds / Pontiac fan in charge over there ...
now to find mile marker 500 and set up a Caddy shop.