Futhest down the alphabet exit letter in your state

[kurumi]

I-110 in Baton Rouge, LA, gets to exit 1H.

[jwolfer]

Florida has a couple C's and  a D on I 95 near downtown Jacksonville.. 353D is the exit for Kings Rd(US 23)

[Charles2]

For Alabama, probably either C or D. Can't think of anything higher than those two, and the highest one that comes to mind is C (Exit 19C on I-565).

Once the new ramps are built on I-20/59 and I-65 at Malfunction Junction in Birmingham, there will be C's and D's on I-65 SB and I-20/59 E/N.  The new 6th Avenue exit from 20/59 will be 124A, 65 SB will switch from 124A to 124B, 65 NB will switch from 124B to 124C, and the new 17th Street exit will be 124D. 

The new 17th Street exit from 65 SB will be 261A, 20/59 W/S will switch from 261A to 261B, 20/59 E/N will switch from 261B to 261C, and the new 6th Avenue exit will be 261D.

[Kacie Jane]

Washington has a D, but it maybe shouldn't. There's a 1D in Vancouver.  Northbound however, it's combined with 1C. Southbound, 1B is missing. So in both directions, there are only three gores, but northbound it goes 1A > 1B > 1C-D, and southbound it goes 1D, 1C, 1A.  (Though it makes sense, since that way the four cross streets have the same exit number in both directions.)

I think there are two other Cs in the state, coincidentally also by the starting terminus of the route: SR 16 in Tacoma, and I-90 in Seattle. The I-90 one definitely shouldn't exist though, since there's no A in either direction.  (2B is for I-5 south, 2C is for I-5 north.)  I think if they had built it as originally planned in the 50s (which would have connected it the 99 viaduct), 2A would have been for 4th Avenue at the current terminus.

[TheStranger]

Exit 1E off the Santa Ana Freeway/US 101 southbound in Los Angeles, Mission Road, is likely the highest lettered exit I can think of in California. (This also leads to a thread idea I'm about to start on a tangent about lettered exits... here: https://www.aaroads.com/forum/index.php?board=12.0 )

[peterj920]

I believe Massachusetts used to have an Exit 22W on MA 128, but not anymore. New Hampshire still has a few exits with W in them.

The OP can correct me if I'm wrong, but I believe the intent of this thread is to identify the last letter used in a continuous sequence for an exit number, and not the "N, S, E, W" designations that states used to use in lieu of the current "A" and "B".

Based on this criteria, Massachusetts only goes up to "C".  However, it occurs in six locations:

Downtown Boston - I-90/MassPike east to I-93 south - Exit 24C
Woburn - I-93 to Commerce Way - Exit 37C
Marlborough - I-495 at Simarano Drive - Exit 23C
Chelmsford - I-495 at Lowell Connector - Exit 35C
Chelmsford - US 3 north to I-495 South - Exit 30C
Bourne - US 6 to MA 6A - Exit 1C

Once the new Kendrick Street/Highland Avenue interchange is opened, there will be a seventh location as well:

Newton - I-95 (MA 128) to Highland Avenue west - Exit 19C

My intention was to see the furthest sequence.  I thought it would be interesting to see the most exits within a mile in each state.

[roadman]

I assumed that the Kendrick Street exit was numbered 19 as a temporary measure so that the existing signs did not need to be updated for the Highland Avenue exits. I also assume that new signage will accompany the final configuration of the Highland Avenue ramps, at which time the "A" will be added for Kendrick Street and the 19A, 19B, 19C sequence will be finalized.

That is my understanding as well.

Roadman also missed a C exit: Lowell Connector at Gorham Street - 5C

So I did - have amended my previous post.  Thanks.

[vdeane]

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.

[hotdogPi]

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

[bassoon1986]

I-110 in Baton Rouge, LA, gets to exit 1H.

Actually it goes to 1J. I and J were added to the I-10 terminus

[KEVIN_224]

CT Route 2 has the following in East Hartford (Exit 5D is for the Putnam Bridge over the Connecticut River into Wethersfield):

5- Riverside Drive | Willow Street (SR 516) [Eastbound exit and westbound entrance]
5A- High Street | Main Street (SR 517) [Signed for High Street eastbound and Main Street westbound]
5B- Sutton Avenue [Eastbound exit and westbound entrance]
5C- Maple Street    [Partial diamond interchange, eastbound exit only]
5D- Route 3 south — Glastonbury, Wethersfield [Trumpet interchange]

[WillWeaverRVA]

If we don't count directional letters, the highest I know of in Virginia is a "D" on southbound I-395 at the Springfield Interchange (Exit 1D).

(Yes, I saw Mapmikey's comment up the thread about the "W" ones on I-81.)

There's also 43D along I-295.

And 50D on I-95 northbound (the exit isn't lettered southbound). I don't think there's anything higher than D in Virginia, aside from the W/E and N/S exits on I-581.

For North Carolina, I-277 has 1E.

[jbnati27]

Looks like Kentucky peaks out at 136C on I-65 in Louisville.

[peterj920]

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. 

[CNGL-Leudimin]

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

Maybe Wyoming Montana, both Dakotas North Dakota, or even Vermont (Edit: peterj920 has pointed out both SD and WY have a C exit). Not Spain (although that is not a state but an entire country), as there are a few Cs around Madrid. Bonus points for that one, as exit numbers are km based and thus exits must be tightly spaced to get further down the alphabet before rolling up over to the next number.

France (sequential exit numbers) uses x.1,  x.2, etc. if they insert an exit between two existing ones. I don't think they go further than x.2, though. Both the UK and Germany use letters, although I have to see a letter other than A. Italy directly doesn't have this issue... because they don't have exit numbers either.

PS: Wyoming even has a couple of D exits, but it appears they use letters according to direction (A=South, B=West, C=North, D=East), so I-80 only has the A and C exits while I-25 gets B and D.

[Rothman]

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.

[TheHighwayMan3561]

Minnesota has a pair of Ds: 242D on I-94 in St. Paul (US 52) and 1D on I-394 in Minnetonka (Ridgedale Dr.)

[PHLBOS]

Once the new Kendrick Street/Highland Avenue interchange is opened, there will be a seventh location as well:

Newton - I-95 (MA 128) to Highland Avenue west - Exit 19C

Nope.  The Kendrick St. exit is now signed as Exit 19; though the signs/tabs were sized for a possible 19A.  The Highland Ave. exits (19A-B) are unchanged.  Saner minds prevailed on this one IMHO.

AFAIK, the current northbound Kendrick Street number is temporary.  In the final configuration of Kendrick Street and Highland Avenue, per the Project #603711 construction plans, the exits will be signed as '19A', '19B', and '19C'.  As all three southbound exits will be accessed off a collector-distributor road, the southbound advance signing will read "EXITS 19C-B-A".

So there will be a southbound exit for Kendrick St. when all is said & done?  For some reason, I thought that access from I-95 to Kendrick was only just for the northbound side.

Never Mind.

[vtk]

The Cincinnati 1G mentioned used to go to at least 1J before the Fort Washington Way cluster was reconstructed. The WKRP theme shows it.

I think there was a 1K also.  I think ODOT had the same basic strategy as used in Kansas City, with I-71 and I-75 not duplicating any exit numbers in the 1x or 2x range.  Now we have I-75 with several 1x and a few 2x exits, and I-71 with a few unnumbered exits south of exit 2.

[MikeTheActuary]

In Memphis TN, the western exit for I-40 westbound to SPR 14 is Exit 1F (aided by the warping of mile 1; the ramp starts at milepost 1B.8)

[dgolub]

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).

[elsmere241]

Delaware used to have a D - I-95 north to I-495 north was Exit 5D for a time.

I think the only C is for the flyover ramp from DE 1 north to I-95 north.

[SD Mapman]

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

Maybe Wyoming Montana, both Dakotas North Dakota, or even Vermont (Edit: peterj920 has pointed out both SD and WY have a C exit). .

Hey, SD has TWO C exits: I-190 and I-229 (both 1C). However, the reconstruction of I-190 might change the exit numbering; it'll probably still be C though. The DOT West River hates making new signs.

[mefailenglish]

Florida has a couple C's and  a D on I 95 near downtown Jacksonville.. 353D is the exit for Kings Rd(US 23)

Florida also has a few X exits on the Turnpike:  2X for the Dolphins Stadium, 4X for the HEFT, and 54X for the 595 Express lanes.

[jwolfer]

Like NJTP 15x ... Not going thru the full alphabet