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Author Topic: Duplicate Interstate numbers?  (Read 7050 times)

ekt8750

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Re: Duplicate Interstate numbers?
« Reply #25 on: January 10, 2017, 12:40:14 PM »

There are 4 duplicate 2-digit interstates (2di), 76, 84, 86, 88.  These are for shortage of numbers and they will never connect.  A case can be said for I-74 but it is technically planned to connect.

For 3di's, there are many duplicates as these are loop or spur routes off its parent.  Only rule is there can't be a duplicate in a single state.

Technically 76 is connected via I-80. It just wouldn't make sense to have that long of a concurrency.
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Rothman

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Re: Duplicate Interstate numbers?
« Reply #26 on: January 10, 2017, 12:43:24 PM »

If 3-digit Interstates (often abbreviated to 3di(s) on this forum) had to be unique across the whole country, then I-95 could only have 9 child routes. There are many more, so some have to be duplicated.

Sometimes they are duplicated even when it isn't necessary: there are two Interstates numbered I-291, even though no problem would result from one of them being renumbered I-491. This usually is not considered a problem.

California currenlty uses 7 out of the 9 possible I-x80s. At times it had an eighth, and, in fact, would have used the ninth (and would probably use two more, if CASR-262 and CASR-237 were constructed as freeways between I-680 and I-880. I-238 was approved as what would (some say should) have been the ninth x80. CASR-180 prevented using it as an I- designation. I-480 was in use at the time. I-238 would be an I-x80, if one were available at the time of its naming.

California also uses 8 out of the 9 I-x05. There is currently no I-705 in California and I-305 exists but isn't signed.

New York has used up all the I-x90s on its own.  My solution has been to get rid of I-790 in Utica if a real additional one is needed.
Now we just need a problem to apply that solution. I don't really see any other I-x90 candidate locations. Even Berkshire spoor can become I-x87.. Although I-1190 would be cool.

Some years ago, there was a I-1090 being suggested for some location.  I'd have to go blow the dust off of some old e-mails.  It was all very informal and never went anywhere.
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Captain Jack

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Re: Duplicate Interstate numbers?
« Reply #27 on: January 10, 2017, 12:49:01 PM »


Hawaii.  I never understood why Hawaii used the H.  Yes, I get that federal bureaucrats use it and even the even more roadgeeky A and PR designations for roads that really don't even exist.  That is just bookkeeping.   But what information is imparted to the motorist by H2 being signed H2 rather than just 2?  You would have to be pretty stupid to not know you were in Hawaii, after all.

Are they referred to by the public as H-3? That would be my only guess why they include the H. Of course, we don't include the "I" so that really doesn't work either.
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jeffandnicole

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Re: Duplicate Interstate numbers?
« Reply #28 on: January 10, 2017, 02:39:41 PM »

...I could see an interstate-quality loop or spur of a 3di being assigned a 4-digit number (i.e. something like I-2405 could be a loop for I-405, etc.)

There are instances of a 3di branching off from a 3di.  In NJ, I-195 branches off of I-295.  In MD, I-370 connects only with I-270.  Personally, it's much easier this way than trying to use a 4di route number.

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michravera

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Re: Duplicate Interstate numbers?
« Reply #29 on: January 10, 2017, 05:26:22 PM »

...I could see an interstate-quality loop or spur of a 3di being assigned a 4-digit number (i.e. something like I-2405 could be a loop for I-405, etc.)

There are instances of a 3di branching off from a 3di.  In NJ, I-195 branches off of I-295.  In MD, I-370 connects only with I-270.  Personally, it's much easier this way than trying to use a 4di route number.

In California, I-380 also branches only from I-280. I-280 doesn't have a real interchange I-80, but it does touch I-680 which does.
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BigRTM

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Re: Duplicate Interstate numbers?
« Reply #30 on: January 10, 2017, 06:04:16 PM »

...I could see an interstate-quality loop or spur of a 3di being assigned a 4-digit number (i.e. something like I-2405 could be a loop for I-405, etc.)

There are instances of a 3di branching off from a 3di.  In NJ, I-195 branches off of I-295.  In MD, I-370 connects only with I-270.  Personally, it's much easier this way than trying to use a 4di route number.

In California, I-380 also branches only from I-280. I-280 doesn't have a real interchange I-80, but it does touch I-680 which does.



And also in downtown St. Petersburg, Florida, I-175 and I-375 are spurs from I-275.
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Re: Duplicate Interstate numbers?
« Reply #31 on: January 10, 2017, 09:20:13 PM »

Now we just need a problem to apply that solution. I don't really see any other I-x90 candidate locations. Even Berkshire spoor can become I-x87.. Although I-1190 would be cool.
If the people who want to turn I-787 into a boulevard get their way, one would be needed for the remaining portion of I-787 as it would no longer connect to its parent.  Of course, I-390 and I-590 could both easily be freed up if needed (I-390->I-99, I-590->I-599).

Technically 76 is connected via I-80. It just wouldn't make sense to have that long of a concurrency.
Doesn't the eastern I-76 begin at I-71, not I-80?
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kalvado

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Re: Duplicate Interstate numbers?
« Reply #32 on: January 11, 2017, 08:20:10 AM »

Now we just need a problem to apply that solution. I don't really see any other I-x90 candidate locations. Even Berkshire spoor can become I-x87.. Although I-1190 would be cool.
If the people who want to turn I-787 into a boulevard get their way, one would be needed for the remaining portion of I-787 as it would no longer connect to its parent.  Of course, I-390 and I-590 could both easily be freed up if needed (I-390->I-99, I-590->I-599).
I suspect keeping it as 787 would be preferred option. Boulevard would likely  be NY-787, as it is in Cohoes... And I hope that doesn't happen anyway
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Re: Duplicate Interstate numbers?
« Reply #33 on: January 11, 2017, 10:11:20 AM »

I'm not suggesting 4di's as being 3di spurs off of other 3dis -- such as I-795 in Maryland -- but for states that may have run out of xYY numbers, such as New York and California. NY has I-990; so if there's another child of the parent I-90, it could be I-1090 no matter if it spurs off I-90 or one of the x90's.
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briantroutman

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Re: Duplicate Interstate numbers?
« Reply #34 on: January 11, 2017, 11:02:13 AM »

Technically 76 is connected via I-80. It just wouldn't make sense to have that long of a concurrency.
Doesn't the eastern I-76 begin at I-71, not I-80?

Correct. On the other hand, if I-76 westbound actually ended at its interchange with I-80, you could think of it as a nearly 1,200-mile silent concurrency.

Something along the lines of what happens to US 422 in Pennsylvania, and as was pointed out in another thread, it appears that PennDOT does consider the route to be continuous, even though signs disappear for 160 miles of overlap with US 322 and US 22.
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Re: Duplicate Interstate numbers?
« Reply #35 on: January 11, 2017, 11:44:29 AM »

Is there a rule against four-character interstates?
Not for Hawaii.  :sombrero:



FTFY  :D (see above)

Some basics about recycling numbers:

-As stated before, 74, 76, 84, 86, and 88 are used twice.  Officials were forced to do this because even numbers increase as you go north--numbers 82-88 should be between I-80 and I-90, for example. (An exception is NC's 74 which is garbage)
-The same number cannot be used twice in the same state.
-3 digit numbers beginning with an odd digit (195, 384, 590, etc.) must be spurs.
-3 digit numbers beginning with an even digit (255, 410, 635, etc.) must go through or around a city.

The only state and interstate to use all 9 prefixes is I-90 in New York (so New York has a 190, 290, 390, all the way up to 990)
There are no legally defined provisions for 4-digit interstates.  I'd be open to seeing an I-1090 in New York though!
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lepidopteran

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Re: Duplicate Interstate numbers?
« Reply #36 on: January 11, 2017, 12:21:12 PM »

Some basics about recycling numbers:

-As stated before, 74, 76, 84, 86, and 88 are used twice.
You could, sort of, argue that 95 is also used twice.  At least for another year or two.
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PHLBOS

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Re: Duplicate Interstate numbers?
« Reply #37 on: January 11, 2017, 12:38:57 PM »

Some basics about recycling numbers:

-As stated before, 74, 76, 84, 86, and 88 are used twice.
You could, sort of, argue that 95 is also used twice.  At least for another year or two.
That's an apples to oranges comparison.  Unlike I-95 (you're obviously referring to the gap in NJ); those other duplicate even-numbered highways were never intended to be linked to each other.  It's worth noting that the western I-84 & I-86 were originally I-80N & I-15W respectively.
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NE2

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Re: Duplicate Interstate numbers?
« Reply #38 on: January 11, 2017, 01:58:57 PM »

Some basics about recycling numbers:

-As stated before, 74, 76, 84, 86, and 88 are used twice.
You could, sort of, argue that 95 is also used twice.  At least for another year or two.
That's an apples to oranges comparison.  Unlike I-95 (you're obviously referring to the gap in NJ); those other duplicate even-numbered highways were never intended to be linked to each other.  It's worth noting that the western I-84 & I-86 were originally I-80N & I-15W respectively.
74 was intended to be linked in a sense (technically the piece in the middle was never added to the IHS, just the NHS as the "I-73/74 High Priority Corridor").
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briantroutman

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Re: Duplicate Interstate numbers?
« Reply #39 on: January 11, 2017, 02:28:30 PM »

It's worth noting that the western I-84 & I-86 were originally I-80N & I-15W respectively.

Likewise, both the eastern and western I-76es had once been designated as I-80S.
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michravera

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Re: Duplicate Interstate numbers?
« Reply #40 on: January 11, 2017, 03:41:07 PM »

I'm not suggesting 4di's as being 3di spurs off of other 3dis -- such as I-795 in Maryland -- but for states that may have run out of xYY numbers, such as New York and California. NY has I-990; so if there's another child of the parent I-90, it could be I-1090 no matter if it spurs off I-90 or one of the x90's.

I completely agree. On I-680, CASR-262 is signed as such. On I-880, it is signed as "To I-680". CASR-262 is only about 2 km long and only the westernmost 700 m or so is freeway. I joked that the eastbound road should be called "I-2680" and the westbound "I-2880", but, if properly upgraded, maybe I-1080 would make sense.
Not everything that works as a spur from or connector to an Interstate has to have an I-label, but it is entirely possible that I-80 in Auburn, Roseville (CASR-65 to US-50/I-305?), or Davis (CASR-113 to I-5) would get a connector to hook up from I-80 to I-5 and that Stockton, Modesto, Merced, Fresno, Visalia, Tulare, and Bakersfield would get spurs into the cities from I-5. ... and I haven't even given proper consideration to connecting I-680 to I-5 north of I-205. Nor, to a southbound connection from San Jose to I-5.
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hbelkins

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Re: Duplicate Interstate numbers?
« Reply #41 on: January 11, 2017, 03:44:35 PM »

Isn't the reason I-238 is designated as such because of a shortage of x80 numbers?
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briantroutman

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Re: Duplicate Interstate numbers?
« Reply #42 on: January 11, 2017, 03:59:22 PM »

Isn't the reason I-238 is designated as such because of a shortage of x80 numbers?

Yes. The inertia of the existing SR designation probably didnít help.
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sparker

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Re: Duplicate Interstate numbers?
« Reply #43 on: January 11, 2017, 06:15:15 PM »

Isn't the reason I-238 is designated as such because of a shortage of x80 numbers?

As I iterated before in another thread, the selection of "238" as an Interstate number back in 1984 was simply a matter of bad (and unforeseen) timing; the number "480" still existed, albeit in state route form, on the stub of SF's Embarcadero Freeway that terminated at Broadway and Battery St., having been deleted from the I-system back in 1965.  Of course, that number itself was involuntarily retired by the Loma Prieta earthquake in 1989, three years after signage was deployed on both I-880 and I-238.  I-480 could have been re-used for the I-238 route otherwise.  Some CA lore has suggested that the number "480" had such negative connotations regarding its original and reviled plans to extend it along the waterfront to the Golden Gate Bridge that the Division of Highways/Caltrans was reluctant to re-use the designation; IMHO there would have been no issue with such re-use as long as it wasn't within SF proper; applying it to an existing facility wouldn't have raised many eyebrows! 
« Last Edit: January 11, 2017, 06:17:25 PM by sparker »
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adventurernumber1

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Re: Duplicate Interstate numbers?
« Reply #44 on: January 12, 2017, 12:42:29 PM »

It seems like the southern Interstate 87 is coming into play in North Carolina and Virginia (later). This means there will be duplicate Interstate 87s. Unless I am for some reason mistaken, this will be the first north-south duplicated interstate number.


I've talked about this in the Southeast sub-forum, but I honestly think the southern I-87 designation would work far better as an Interstate 46. Interstate 87 isn't really breaking any rules in the grid or anything, I just personally think it isn't the best number for the interstate, as avoiding the number 87 would avoid having yet another duplication of a number, and the corridor is a little more east-west than it is north-south anyhow.


With that said, it sounds like we will have to accept the Interstate 87 numbering, and with that said, I would be all for extending this new I-87 corridor north onto the Delmarva Peninsula, up to Wilmington, Delaware, then possibly have a brief concurrency with I-95 then I-295 into New Jersey, then have I-87 routed along the New Jersey Turnpike and later concurrent with I-95 along it until reaching New York City, and reaching the current, northern Interstate 87. Should that happen, the southernmost section of current I-87 from I-95 to I-278 could be an unused even I-x87 interstate designation, such like that of how I-75 in downtown Knoxville, Tennessee became Interstate 275. That might potentially sound wacky - possibly either like a really good idea or a really bad idea. But it would connect the two I-87s. While a lot of I-87 would be out of the grid, its southernmost part in North Carolina between Raleigh and I-95, and all of the current, northern I-87 in New York would not be. This could also work since it looks like they aren't going to change the numbering of I-97 and I-99 (which are both badly numbered, but that we have all long accepted, besides our fantasizing), and should a proposed Interstate 101 still come into play, it could connect I-87 in NC to I-95 in GA or SC, serving the east coast in that region. That is the best way (that I know of) we could modify the creation of this southern, duplicate Interstate 87.
« Last Edit: January 12, 2017, 12:55:18 PM by adventurernumber1 »
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sparker

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Re: Duplicate Interstate numbers?
« Reply #45 on: January 13, 2017, 04:08:32 PM »

It's always been a bit of a mystery to me that in CT and MA there are the two I-291 iterations only about 30-odd miles apart (road mileage on parent I-91).  IMO, that's something that should have been addressed 50+ years ago with a phone call between the agencies and another one to AASHTO (conference call, anyone?) -- let the agencies flip a coin, with the winner getting to choose their designation, while the other one gets any other even-first-digit x91 of their choosing!  Having two identical auxiliary numbers that close together, regardless of separate jurisdictions, isn't the best outcome for purposes of navigation -- particularly with motorists unfamiliar with the territory.  Since New England is arguably the most compact of national regions (to the point that they had their own routing system pre-U.S. route commissioning, indicating some level of previous inter-state cooperation), it's perplexing that considerations such as this seem to often fall by the wayside, so to speak! 

 
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Re: Duplicate Interstate numbers?
« Reply #46 on: January 13, 2017, 04:34:54 PM »

It's always been a bit of a mystery to me that in CT and MA there are the two I-291 iterations only about 30-odd miles apart (road mileage on parent I-91).  IMO, that's something that should have been addressed 50+ years ago with a phone call between the agencies and another one to AASHTO (conference call, anyone?) -- let the agencies flip a coin, with the winner getting to choose their designation, while the other one gets any other even-first-digit x91 of their choosing!  Having two identical auxiliary numbers that close together, regardless of separate jurisdictions, isn't the best outcome for purposes of navigation -- particularly with motorists unfamiliar with the territory.
More of a What came first, the chicken or the egg? scenario here.

MA's I-291 was fully-completed circa 1971.  However, most of what is CT's I-291 existed as far back as 1957 as CT 291.  Even though it wouldn't be redesignated as I-291 until 1994; CT's plans/proposals for a much longer and elaborate I-291 predates its MA counterpart.

That said, I don't believe that too many people will confuse the MA I-291 for the CT I-291.

BTW, I don't believe that concept of conference calls (3-way or more calling) existed back in the 50s or even the 70s.
« Last Edit: January 13, 2017, 04:37:05 PM by PHLBOS »
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Re: Duplicate Interstate numbers?
« Reply #47 on: January 13, 2017, 04:39:21 PM »

I'm not suggesting 4di's as being 3di spurs off of other 3dis -- such as I-795 in Maryland -- but for states that may have run out of xYY numbers, such as New York and California. NY has I-990; so if there's another child of the parent I-90, it could be I-1090 no matter if it spurs off I-90 or one of the x90's.

I completely agree. On I-680, CASR-262 is signed as such. On I-880, it is signed as "To I-680". CASR-262 is only about 2 km 1.2 miles long and only the westernmost 700 m 2/5 mile or so is freeway. I joked that the eastbound road should be called "I-2680" and the westbound "I-2880", but, if properly upgraded, maybe I-1080 would make sense.

We've had plenty of interstates (3dis) less than a mile before, so length may not be a factor.
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Re: Duplicate Interstate numbers?
« Reply #48 on: January 13, 2017, 08:49:13 PM »

It's always been a bit of a mystery to me that in CT and MA there are the two I-291 iterations only about 30-odd miles apart (road mileage on parent I-91).

I agree. I've always thought the 3DI rule should be no repeats in the same state and no repeats if the roads in question are less than 200 miles (or whatever) apart. If this were the rule, there would be, in particular, a whole bunch of 295s to change.
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Re: Duplicate Interstate numbers?
« Reply #49 on: January 15, 2017, 02:22:33 AM »

The I-H201 shields and the Clearview font makes those signs look so video game-ish.   If someone showed you a photo of those signs at the turn of the century (2000), nobody would believe that those were real since neither the route nor font was in place yet.
Objection: H-201 was commissioned in 1989. It wasn't signed until 2004, but the route was, in fact, already in place.
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