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National Boards => General Highway Talk => Topic started by: frankenroad on January 17, 2020, 03:00:36 PM

Title: Exit Number Suffixes (Suffices?)
Post by: frankenroad on January 17, 2020, 03:00:36 PM
Sorry if this is a repeat - I searched and did not find a similar thread.

When I-75 first enters Ohio, there are numerous exits that are numbered 1A  through 1G.  Some are northbound only and some are southbound only.  Before a significant reduction in exits, about 15 years ago, I believe they went up to 1K or 1L (there was no 1I).

Of course, if Ohio used 0 as an exit number, probably 1A to 1E would be 0A to 0E, and 1F & 1G would be 1A & 1B.

Are there other places where there are more than four suffices?  I 'm pretty sure I have seen a -D somewhere besides Cincinnati.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: hotdogPi on January 17, 2020, 03:01:49 PM
Kansas City has 2A-2Y.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: kphoger on January 17, 2020, 04:01:56 PM
Quote from: 1 on January 17, 2020, 03:01:49 PM
Kansas City has 2A-2Y.

...but is missing 2I and 2O.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: hotdogPi on January 17, 2020, 04:10:38 PM
Have there ever been any exits suffixed with CH in the Spanish-speaking world?
Title: Re: Exit Number Suffixes (Suffices?)
Post by: roadman on January 17, 2020, 04:57:22 PM
Quote from: kphoger on January 17, 2020, 04:01:56 PM
Quote from: 1 on January 17, 2020, 03:01:49 PM
Kansas City has 2A-2Y.

...but is missing 2I and 2O.

Probably because they could be too easily confused for the numerals 21 and 20.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: sprjus4 on January 17, 2020, 05:04:20 PM
Not exactly the OP, but I-581 through Roanoke, VA has Exit 1N - 1S, Exit 2N - 2S, Exit 3E - 3W then 3C (added later), and Exit 4E - 4W.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: CtrlAltDel on January 17, 2020, 05:16:42 PM
I-94 in Chicago has eight suffixes at mile 51:

51A Lake Street
51B Randolph Street
51C Washington Boulevard
51D Madison Street
51E Monroe Street
51F Adams Street
51G Jackson Boulevard
51H Interstate 290 West
51I Congress Parkway East

Miles 52 and 53 also have three exits each. Moreover, for better or for worse, every mile from 43 to 53 has at least two exits.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: CNGL-Leudimin on January 17, 2020, 06:01:46 PM
Quote from: 1 on January 17, 2020, 04:10:38 PM
Have there ever been any exits suffixed with CH in the Spanish-speaking world?

AFAIK there is no exit suffixed further than C in Spain. I don't think there was a CH ever.

Using km less suffixes would exist. However amazingly the Chicago thing would be kept intact, with the entire set of exit 51s becoming exit 82s, I thought some would become exit 83 instead (It would if they switched at .5 instead of at .0).
Title: Re: Exit Number Suffixes (Suffices?)
Post by: TheGrassGuy on January 17, 2020, 06:22:52 PM
Quote from: 1 on January 17, 2020, 03:01:49 PM
Kansas City has 2A-2Y.
I wonder why they did that; the loop is more than one mile long, isn't it?
Title: Re: Exit Number Suffixes (Suffices?)
Post by: US 89 on January 17, 2020, 06:30:03 PM
Quote from: TheGrassGuy on January 17, 2020, 06:22:52 PM
Quote from: 1 on January 17, 2020, 03:01:49 PM
Kansas City has 2A-2Y.
I wonder why they did that; the loop is more than one mile long, isn't it?

The loop is four miles long, but the legs are parts of I-35, I-70, and I-670 and would be normally be numbered according to the mileposts of those routes. But the mileage on all three interstates is such that they all would reach milepost 2 near or within the loop, so it's less confusing to just make the entire loop "exit 2" with letter suffixes to avoid duplicating exits.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: bassoon1986 on January 19, 2020, 05:42:46 PM
I-110 in Baton Rouge has 1A through 1J. And includes 1i


iPhone
Title: Re: Exit Number Suffixes (Suffices?)
Post by: CtrlAltDel on January 19, 2020, 07:54:17 PM
Quote from: bassoon1986 on January 19, 2020, 05:42:46 PM
I-110 in Baton Rouge has 1A through 1J. And includes 1i

I am nothing short of amazed at just how many unnecessary left exits and entrances there are on that stretch of highway.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: deathtopumpkins on January 20, 2020, 08:56:14 AM
Quote from: bassoon1986 on January 19, 2020, 05:42:46 PM
I-110 in Baton Rouge has 1A through 1J. And includes 1i

And sure enough, Google Maps mistakenly identifies exit 1I as exit 11... this is why you should skip I and O.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: MNHighwayMan on January 20, 2020, 10:05:24 AM
Quote from: deathtopumpkins on January 20, 2020, 08:56:14 AM
Quote from: bassoon1986 on January 19, 2020, 05:42:46 PM
I-110 in Baton Rouge has 1A through 1J. And includes 1i
And sure enough, Google Maps mistakenly identifies exit 1I as exit 11... this is why you should skip I and O.

Or why Google should do some more data verification.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: deathtopumpkins on January 20, 2020, 01:17:52 PM
Regardless of how much data verification Google does, there's still the likelihood of someone driving by at highway speed mistakenly identifying an exit as 11 instead of 1I, or 10 instead of 1O.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: Hot Rod Hootenanny on January 20, 2020, 02:05:28 PM
When ODOT got around to adding exit numbers to OH 315 in Columbus, in the last year or two, what used to be considered three different exits (US 62-Oh 3, US 40, and I-670/US 33) are now labeled as exits 1A -1F
Title: Re: Exit Number Suffixes (Suffices?)
Post by: TEG24601 on January 20, 2020, 05:06:13 PM
I-205 in Downtown Portland, OR has 1-A through 1-D.


I-5 in Vancouver, WA has 1-A through 1-D, even though C and D share the same off ramp.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: sbeaver44 on January 20, 2020, 07:42:15 PM
Quote from: deathtopumpkins on January 20, 2020, 01:17:52 PM
Regardless of how much data verification Google does, there's still the likelihood of someone driving by at highway speed mistakenly identifying an exit as 11 instead of 1I, or 10 instead of 1O.
I think Google uses (imperfect) image recognition to decipher the exit numbers because I had to correct an exit 45 somewhere above Williamsport on US 15 (I think it was Exit 162)

However, the exit definitely had a 45 mph advisory ramp speed...
Title: Re: Exit Number Suffixes (Suffices?)
Post by: TheGrassGuy on January 21, 2020, 06:35:11 AM
Google sometimes also gives exit numbers to non-exits! US-60 and US-70 in Globe is Exit 1.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: sbeaver44 on January 21, 2020, 10:35:29 AM
Google's image recognition also annoys me when it puts the face blur over road signs in GSV.
Title: Re: Exit Number Suffixes (Suffices?)
Post by: roadman65 on January 21, 2020, 12:07:30 PM
If Florida did not go mile based, I-4's exit numbers between US 27 and US 192 would have Exit 24E for SR 417.  In fact it briefly did and World Drive was Exits 24 C & D.  A, and B were reserved both for SR 429 using the B suffix (which was built after the change and is Exit 60, but would have been most likely Exit 24B) and A, for I assume, the needed Poinciana Parkway extension, which will probably be built in 2040.)
Title: Re: Exit Number Suffixes (Suffices?)
Post by: dgolub on January 25, 2020, 09:25:11 AM
The Long Island Expressway (I-495) in New York has exits 22A-E.