Futhest down the alphabet exit letter in your state

[Scott5114]

In Oklahoma, it's 1G, on I-235.

[PurdueBill]

Which states don't have C or higher, if any?

I'm sure quite a few western states don't.  North Dakota only has one interchange where exits reach B, which would be the I-29/I-94 interchange.  Montana, and Idaho also do not have states that don't reach C.  South Dakota does with Exit 1C off of I-190, along with Wyoming in the I-80/I-25 interchange area where they both have a C exit. 

Wyoming kinda cheats though, with exits 359 A-C off I-80 for I-25 and exits 8B-D off I-25 for I-80.  Having driven through there, you wonder if you missed an exit or two, but nope--the successive cloverleaf ramps skip a letter so indeed you didn't miss something. 

[CNGL-Leudimin]

I had already noted that based on observations from Street View. Without that cheating, Wyoming doesn't quite reach C. I was surprised about Idaho, I thought it would go to C around Boise.

[coatimundi]

New Mexico has one C & D, along I-40 at and by the I-25 interchange. Nothing else goes over B.

[roadfro]

Nevada only goes up to "C", with only one true instance and one sort-of instance.

On I-515/US 95 in Las Vegas, the exit to I-15 is exits 76A & 76B (north & south, or south & north, depending on direction) while exit 76C is for Martin L. King Blvd.

On northbound US 95, there is an HOV-lane exit to Summerlin Pkwy labeled exit 81C. I don't really count this one, because exit 81A already goes to Summerlin Pkwy.

[ILRoad55]

I-190 has an exit D in Chicago

[CNGL-Leudimin]

It gets crushed by exit 51I along I-94 (and I-90, but that section uses exit numbers from I-94).

[DandyDan]

Nebraska goes to 2D on I-480 on the north side of downtown Omaha, for the 20th St. and Capitol Avenue exit.  I-80, I-180 and US 34 in Lincoln have an exit 401D for eastbound I-80, but that is based off a directional system instead of a sequential system.

[epzik8]

Maryland only has C or D and it could be in Baltimore or Frederick.

[7/8]

The highest letter I can find in Ontario is a C on the 416 (Exit 75C Holly Acres Rd/Richmond Rd).

[RestrictOnTheHanger]

In New York, excluding directional suffixes, it is 1D on I-95.

How about 9P on the Grand Central Parkway?

I did forget about that one, but I would think it falls in the same spirit as excluding 15X on the New Jersey Turnpike.

Directional suffixes almost always disappear when a state goes mileage based (exception being the NJTP; I refer to the Meadowlands/MetLife Stadium as 16W).

The Turnpike is still sequential, despite the rest of the state going mile-based.

I'm surprised there wasn't one deeper in the alphabet amongst all those crazy Long Island prefixed exit numbers.

Those are prefixes, not suffixes.  The prefixed exit numbers generally just have an E or W suffix.

There is, however, exit 22E for College Point Boulevard when heading east on the Long Island Expressway (I-495).

Throws me for a loop every time I have to use that exit complex, so used to E meaning East.

On a related note, I wonder why the exits going westbound dont all have letters like on the eastbound side.

Currently, eastbound is:

21 for 108th St
22A for Grand Central / Northern State Eastboumd
22B for GCP Westbound
22C/D for the Van Wyck/678  Southbound and Northbound
22E for the service road/College Point Blvd (which maybe shouldnt be signed as an exit anyway since it uses the service road)

Westbound:

22B for College Point Blvd, use this for VWE/678
22A for GCP Westbound/Eastbound and 108th St, all with unnumbered ramps.

Why not have 22D,C,B,A or 22C,B,A,21?


I prefer directional suffixes as its quicker confirmation of which ramp comes first and which one you get off at. LI usually saves A,B,C suffices for supplemental exits, and even then sometimes piles on a direction (ie 28AS, 28AN). NYC is really inconsistent with their exit signage.