We all know the numbering rules for Interstates, including at least a vague notion of the rules for 3DIs–first digit odd: spur, first digit even: loop/beltway.
And if you look at the examples in the MUTCD, they're all very simplified. A spur connects with its parent at one point, extends outward in one direction, and terminates at some destination. Loops always reconnect to their parent. "Link" 3DIs that connect two Interstates but do not return to their parent–like I-280 in NJ, for example–aren't specifically listed in the examples, but the consensus seems to be that a 3DI ending at an Interstate on both ends qualifies for an even first digit. Not that far away (in PA), though, we have I-380, which also connects Interstates at each end. Obviously the real world is infinitely more complicated than the tidy examples, and no matter how you want to interpret the rules, they're being broken in many places.
So–multi-part question–what is your interpretation of the existing rule (for odd/even numbering), and in either a pragmatic or perfect world, what do you think it should be?
It seems to me that the only really useful information that odd/even can communicate is whether or not the 3DI returns to the parent. If I'm driving south on I-95 to Florida, and in the middle of Virginia I see an exit for I-295, I can take it with the security of knowing I'll end up back on I-95 eventually. But if I'm driving north again on I-75 and see I-675 as I'm approaching Atlanta, just knowing that it connects to another Interstate (any Interstate) doesn't appear to help me much. If I knew what Interstate it connected to, then I probably have a map, so the entire odd/even scheme is already superfluous to me. The numbering scheme primarily helps the person navigating without a map.
https://www.aaroads.com/forum/index.php?board=20.0
Quote from: briantroutman on April 17, 2013, 02:51:08 AM
It seems to me that the only really useful information that odd/even can communicate is whether or not the 3DI returns to the parent. If I'm driving south on I-95 to Florida, and in the middle of Virginia I see an exit for I-295, I can take it with the security of knowing I'll end up back on I-95 eventually.
So what do you do about a 3/4 loop, like, well, 295? Have a 264/295 overlap?
An even x64 from I-64 to I-64 and I-295 from I-95 to I-95–with the overlap in the NE corner–would seem to make sense. That way, I-64 motorists could easily identify their bypass, and I-95 motorists likewise.
I'll skip right to the 3di's that connect to another interstate, but not back to the parent.
I generally want to go with even numbers. To me it's more important to get across the message that "this freeway is libel to dump you onto a non-freeway if you keep going" when using odd 3di's. But I'm not entirely opposed to odd numbers, especially when you're running low on even 3di's.
Beltlines, even incomplete ones, should have one number (sorry, MSP) and should most certainly be an interstate regardless of tollness (I'm looking at you, Denver, Nashville, Phoenix, Orlando...).
Generally, I'd prefer to keep the mainline running through the city and use even spurs for beltlines/bypasses.
I have an odd preference for I-5xx airport spurs even though I-1xx's are slightly more common. But I'm a huge proponent of interstate spurs into airport terminals because of the intermodal usefulness. (I've got dozens on my fictional maps.)
I don't agree. A beltway is even-numbered, but you would never use that to return to the parent. If you're going around randomly taking exits without knowing where they go, I have no sympathy for you getting lost. I do think the anomalies like I-540 should be corrected, though.
Quote from: Steve on April 17, 2013, 06:51:08 PM
A beltway is even-numbered, but you would never use that to return to the parent.
I might. a beltway may function as a bypass of a city. I've definitely taken 270 around the south side of Columbus, OH, as opposed to 70 straight through, for traffic reasons.
Quote from: agentsteel53 on April 17, 2013, 06:52:53 PM
Quote from: Steve on April 17, 2013, 06:51:08 PM
A beltway is even-numbered, but you would never use that to return to the parent.
I might. a beltway may function as a bypass of a city. I've definitely taken 270 around the south side of Columbus, OH, as opposed to 70 straight through, for traffic reasons.
But you need to know that it's useful for that purpose. I-295 around Jacksonville is unlikely to be better, and even if it is, do you head east or west?
I-295 around the east side of Jax is totally better (1.2 miles longer). Even more so when I-795 is built.
Quote from: Steve on April 17, 2013, 07:10:12 PM
But you need to know that it's useful for that purpose. I-295 around Jacksonville is unlikely to be better, and even if it is, do you head east or west?
do I take 405 or 5 through Los Angeles? the numbering will not help you glean the traffic...
the fact that there are three options (one leg of 295, the other leg of 295, or just plain 95) as opposed to two (405 or 5) does not invalidate the use of an even number for a full circular beltway.
I actually agree with the a lot of the original post.
All the technicalities of 3DI numbering aside, the simple notion of "is this route itself mostly a belt/loop/bypass, or mostly a spur" should be the primary litmus test for even or odd prefixes.
For instance, I've always thought that I-270 in Maryland should be an odd numbered 3DI; it's a functionally straight and direct route from Frederick to the DC Metro area with absolutely NO belt/bypass/loop qualities to it.
Of course, there are plenty of examples of 3DI's that, for whatever reason, don't neatly fall into either category. (The specific example I'm thinking of is the relatively recently extended I-376 here in Pittsburgh, which is now a half belt (loop?) that then becomes a spur north.), in which case, just take an available number.
All this being said, I personally wouldn't advocate re-numbering a preexisting 3DI just for these reasons. I doubt the average motorist knows/cares enough about 3DI rules for it to really matter (especially in this age of G.P.S.), and the renumbering benefits wouldn't outweigh any potential confusion (even short-term) and resigning costs.
Quote from: Steve on April 17, 2013, 06:51:08 PM
I don't agree. A beltway is even-numbered, but you would never use that to return to the parent. If you're going around randomly taking exits without knowing where they go, I have no sympathy for you getting lost. I do think the anomalies like I-540 should be corrected, though.
And I-520.
In what way does I-605 CA function as a loop off I-5?
Quote from: national highway 1 on April 17, 2013, 08:50:09 PM
In what way does I-605 CA function as a loop off I-5?
Without looking at a map to remind myself of exactly which freeway 605 is, I'm guessing it's in the way that California has an extreme shortage of 3di numbers.
Quote from: national highway 1 on April 17, 2013, 08:50:09 PM
In what way does I-605 CA function as a loop off I-5?
it falls in quite nicely with the "ends at another interstate" rule... on both ends, actually. it connects 405 to 210.
Quote from: Mr_Northside on April 17, 2013, 07:56:27 PMAll this being said, I personally wouldn't advocate re-numbering a preexisting 3DI just for these reasons. I doubt the average motorist knows/cares enough about 3DI rules for it to really matter (especially in this age of G.P.S.), and the renumbering benefits wouldn't outweigh any potential confusion (even short-term) and resigning costs.
FWIW, that didn't stop the Feds from
mandating many states (TX & MN being the sole exceptions) to renumber
all their suffixed 2dis to 3dis decades ago. So,
in theory, similar
could happen again.
In the case of the recent I-376 extension (onto PA 60 & the lower leg of I-279); another 3di number could've been selected for the highway portion of PA 60 and lower I-279 could've been left alone. Since the upper-end of PA 60 ends on I-80 and the lower ends on I-79, it could've been easily redesignated as I-x80 or I-x79; thereby retaining its status as a north-south road.
I wondered why they used 376 and not 279.
Probably to avoid direction-swapping.
Quote from: vdeane on April 18, 2013, 10:54:49 AM
Probably to avoid direction-swapping.
That hasn't been a problem in a lot of other instances.When the I-265 loop is completed in Kentucky and Indiana, it will have three directions (E/W, N/S and W/E).
Quote from: hbelkins on April 18, 2013, 12:06:02 PM
Quote from: vdeane on April 18, 2013, 10:54:49 AM
Probably to avoid direction-swapping.
That hasn't been a problem in a lot of other instances.When the I-265 loop is completed in Kentucky and Indiana, it will have three directions (E/W, N/S and W/E).
It might have been due to the distance and the fact that it wouldn't really form a loop or even a 3/4 loop like I-265.
IMHO, the I-376 extension might've been better as either I-379 or I-580. But, this is Pennsylvania which chose to use I-476 north to Scranton from Philadelphia.
Quote from: Brandon on April 18, 2013, 12:09:41 PMIMHO, the I-376 extension might've been better as either I-379 or I-580.
Agreed.
Quote from: Brandon on April 18, 2013, 12:09:41 PMBut, this is Pennsylvania which chose to use I-476 north to Scranton from Philadelphia Chester.
FTFY :)
Quote from: Mr_Northside on April 17, 2013, 07:56:27 PM
For instance, I've always thought that I-270 in Maryland should be an odd numbered 3DI; it's a functionally straight and direct route from Frederick to the DC Metro area with absolutely NO belt/bypass/loop qualities to it.
I agree. Since Maryland no longer has an I-170, its I-270 really ought to be I-170. And that's still a lower-numbered 3DI than its short spur, I-370.
Quote from: briantroutman on April 17, 2013, 02:51:08 AM
We all know the numbering rules for Interstates, including at least a vague notion of the rules for 3DIs–first digit odd: spur, first digit even: loop/beltway.
Should
4DIs be allowed in states that "need" more 3DIs?
Why not? Kentucky has four-digit state routes, and Virginia has four-digit secondary state routes.
Quote from: hbelkins on April 18, 2013, 11:46:05 PM
Why not? Kentucky has four-digit state routes, and Virginia has four-digit secondary state routes.
Well, we actually have FIVE-digit secondary state routes, they just haven't made it to shields yet. ;)
Quote from: cpzilliacus on April 18, 2013, 08:47:08 PM
Quote from: briantroutman on April 17, 2013, 02:51:08 AM
We all know the numbering rules for Interstates, including at least a vague notion of the rules for 3DIs–first digit odd: spur, first digit even: loop/beltway.
Should 4DIs be allowed in states that "need" more 3DIs?
There is, effectively, already a 4di: I-H201, if you consider the 'H' as part of the number.
Quote from: PHLBOS on April 18, 2013, 09:27:27 AM
Quote from: Mr_Northside on April 17, 2013, 07:56:27 PMAll this being said, I personally wouldn't advocate re-numbering a preexisting 3DI just for these reasons. I doubt the average motorist knows/cares enough about 3DI rules for it to really matter (especially in this age of G.P.S.), and the renumbering benefits wouldn't outweigh any potential confusion (even short-term) and resigning costs.
FWIW, that didn't stop the Feds from mandating many states (TX & MN being the sole exceptions) to renumber all their suffixed 2dis to 3dis decades ago. So, in theory, similar could happen again.
I suppose it
is possible. Though I'm not betting on it. And I'd be against it (not that the Feds would call me up and ask my opinion). Like I said, personally I think it's just as well to let sleeping
dogs[questionable/incorrect first 3DI digits] lie.
Quote from: PHLBOS on April 18, 2013, 09:27:27 AM
In the case of the recent I-376 extension (onto PA 60 & the lower leg of I-279); another 3di number could've been selected for the highway portion of PA 60 and lower I-279 could've been left alone.
Though, that would have defeated part of the purpose of what they were trying to do.
Part of it was business reasons; the belief that an I-designation will help development, and that Pittsburgh International Airport needed "to be served" by an interstate. Just how important/beneficial it
actually is, I think, can be debated....
But the rest of the reason was to unify a continuous highway that was a hodgepodge of numbers under one route designation, so they wouldn't want one number to just end, and other to just begin.
Quote from: cpzilliacus on April 18, 2013, 08:47:08 PM
Should 4DIs be allowed in states that "need" more 3DIs?
I'd have no beef with that, in situations where there is no other option.
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMQuote from: PHLBOS on April 18, 2013, 09:27:27 AM
In the case of the recent I-376 extension (onto PA 60 & the lower leg of I-279); another 3di number could've been selected for the highway portion of PA 60 and lower I-279 could've been left alone.
Though, that would have defeated part of the purpose of what they were trying to do.
Part of it was business reasons; the belief that an I-designation will help development, and that Pittsburgh International Airport needed "to be served" by an interstate. Just how important/beneficial it actually is, I think, can be debated....
To be clear, I wasn't disputing the redesignation of PA 60 into an Interstate (and the reasonings behind the move may be close to what you mentioned in your post). I was commenting on the number choice and the fact that such a choice involved/required a
complete renumbering of mile markers & interchange numbers for
three different highways rather than one; especially a few years after a statewide revamp of interchange numbers (to mile-marker based) was already instituted.
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMBut the rest of the reason was to unify a continuous highway that was a hodgepodge of numbers under one route designation, so they wouldn't want one number to just end, and other to just begin.
While I can relate to that reasoning; IMHO, PennDOT should've at least made an attempt to
properly use the appropriate 3di prefix (in this case, even since it's clearly not a spur). If one's going to change the designation of
several roads in the process; why not do it properly?
The current changes not only have an odd 3di behave more like an even 3di; but the truncating of I-279 in Pittsburgh, now makes that road, in theory, a spur.
Fictional territory here; but IMHO the current I-376 should be I-276* (or I-280) and the current I-279 should be I-379.
*Current I-276 along the eastern end of the PA Turnpike could be redesignated as either I-876 or 695 (since it will be ending at I-95 in the foreseable future). Most people in the Delaware Valley don't even refer to that stretch of Turnpike as I-276 (except when reciting signs) so a number change there isn't much of a big deal in their eyes.
Quote from: agentsteel53 on April 17, 2013, 09:10:55 PM
Quote from: national highway 1 on April 17, 2013, 08:50:09 PM
In what way does I-605 CA function as a loop off I-5?
it falls in quite nicely with the "ends at another interstate" rule... on both ends, actually. it connects 405 to 210.
I've always thought of I-605 as kind of a "double spur"-
A spur from I-5 northbound into the San Gabriel Valley;
and a spur from I-5 southbound to east Long Beach/coastal Orange County.
On an earlier thread I think we also talked about I-605 and I-405 making a loop/bypass from I-5 of Anaheim/Santa Ana.
Quote from: PHLBOS on April 19, 2013, 04:05:37 PM
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMQuote from: PHLBOS on April 18, 2013, 09:27:27 AM
In the case of the recent I-376 extension (onto PA 60 & the lower leg of I-279); another 3di number could've been selected for the highway portion of PA 60 and lower I-279 could've been left alone.
Though, that would have defeated part of the purpose of what they were trying to do.
Part of it was business reasons; the belief that an I-designation will help development, and that Pittsburgh International Airport needed "to be served" by an interstate. Just how important/beneficial it actually is, I think, can be debated....
To be clear, I wasn't disputing the redesignation of PA 60 into an Interstate (and the reasonings behind the move may be close to what you mentioned in your post). I was commenting on the number choice and the fact that such a choice involved/required a complete renumbering of mile markers & interchange numbers for three different highways rather than one; especially a few years after a statewide revamp of interchange numbers (to mile-marker based) was already instituted.
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMBut the rest of the reason was to unify a continuous highway that was a hodgepodge of numbers under one route designation, so they wouldn't want one number to just end, and other to just begin.
While I can relate to that reasoning; IMHO, PennDOT should've at least made an attempt to properly use the appropriate 3di prefix (in this case, even since it's clearly not a spur). If one's going to change the designation of several roads in the process; why not do it properly?
The current changes not only have an odd 3di behave more like an even 3di; but the truncating of I-279 in Pittsburgh, now makes that road, in theory, a spur.
Fictional territory here; but IMHO the current I-376 should be I-276* (or I-280) and the current I-279 should be I-379.
*Current I-276 along the eastern end of the PA Turnpike could be redesignated as either I-876 or 695 (since it will be ending at I-95 in the foreseable future). Most people in the Delaware Valley don't even refer to that stretch of Turnpike as I-276 (except when reciting signs) so a number change there isn't much of a big deal in their eyes.
Does ANYONE follow the official 3di numbering rules? I know NYSDOT doesn't care and never has.
Quote from: vdeane on April 20, 2013, 12:37:00 PM
Quote from: PHLBOS on April 19, 2013, 04:05:37 PM
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMQuote from: PHLBOS on April 18, 2013, 09:27:27 AM
In the case of the recent I-376 extension (onto PA 60 & the lower leg of I-279); another 3di number could've been selected for the highway portion of PA 60 and lower I-279 could've been left alone.
Though, that would have defeated part of the purpose of what they were trying to do.
Part of it was business reasons; the belief that an I-designation will help development, and that Pittsburgh International Airport needed "to be served" by an interstate. Just how important/beneficial it actually is, I think, can be debated....
To be clear, I wasn't disputing the redesignation of PA 60 into an Interstate (and the reasonings behind the move may be close to what you mentioned in your post). I was commenting on the number choice and the fact that such a choice involved/required a complete renumbering of mile markers & interchange numbers for three different highways rather than one; especially a few years after a statewide revamp of interchange numbers (to mile-marker based) was already instituted.
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMBut the rest of the reason was to unify a continuous highway that was a hodgepodge of numbers under one route designation, so they wouldn't want one number to just end, and other to just begin.
While I can relate to that reasoning; IMHO, PennDOT should've at least made an attempt to properly use the appropriate 3di prefix (in this case, even since it's clearly not a spur). If one's going to change the designation of several roads in the process; why not do it properly?
The current changes not only have an odd 3di behave more like an even 3di; but the truncating of I-279 in Pittsburgh, now makes that road, in theory, a spur.
Fictional territory here; but IMHO the current I-376 should be I-276* (or I-280) and the current I-279 should be I-379.
*Current I-276 along the eastern end of the PA Turnpike could be redesignated as either I-876 or 695 (since it will be ending at I-95 in the foreseable future). Most people in the Delaware Valley don't even refer to that stretch of Turnpike as I-276 (except when reciting signs) so a number change there isn't much of a big deal in their eyes.
Does ANYONE follow the official 3di numbering rules? I know NYSDOT doesn't care and never has.
Florida looks pretty solid.
If PennDOT and PTC want to retain the abomination known as Breezewood, then FHWA should have I-70 re-routed by way of present-day I-68 and Pa. 43.
Current I-70 between California, Pennsylvania and New Stanton can be I-770; and Breezewood and Hancock, Maryland can become I-970.
Is this too far off-topic from 3DI routes?
Quote from: vdeane on April 20, 2013, 12:37:00 PM
Quote from: PHLBOS on April 19, 2013, 04:05:37 PM
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMQuote from: PHLBOS on April 18, 2013, 09:27:27 AM
In the case of the recent I-376 extension (onto PA 60 & the lower leg of I-279); another 3di number could've been selected for the highway portion of PA 60 and lower I-279 could've been left alone.
Though, that would have defeated part of the purpose of what they were trying to do.
Part of it was business reasons; the belief that an I-designation will help development, and that Pittsburgh International Airport needed "to be served" by an interstate. Just how important/beneficial it actually is, I think, can be debated....
To be clear, I wasn't disputing the redesignation of PA 60 into an Interstate (and the reasonings behind the move may be close to what you mentioned in your post). I was commenting on the number choice and the fact that such a choice involved/required a complete renumbering of mile markers & interchange numbers for three different highways rather than one; especially a few years after a statewide revamp of interchange numbers (to mile-marker based) was already instituted.
Quote from: Mr_Northside on April 19, 2013, 03:05:42 PMBut the rest of the reason was to unify a continuous highway that was a hodgepodge of numbers under one route designation, so they wouldn't want one number to just end, and other to just begin.
While I can relate to that reasoning; IMHO, PennDOT should've at least made an attempt to properly use the appropriate 3di prefix (in this case, even since it's clearly not a spur). If one's going to change the designation of several roads in the process; why not do it properly?
The current changes not only have an odd 3di behave more like an even 3di; but the truncating of I-279 in Pittsburgh, now makes that road, in theory, a spur.
Fictional territory here; but IMHO the current I-376 should be I-276* (or I-280) and the current I-279 should be I-379.
*Current I-276 along the eastern end of the PA Turnpike could be redesignated as either I-876 or 695 (since it will be ending at I-95 in the foreseable future). Most people in the Delaware Valley don't even refer to that stretch of Turnpike as I-276 (except when reciting signs) so a number change there isn't much of a big deal in their eyes.
Does ANYONE follow the official 3di numbering rules? I know NYSDOT doesn't care and never has.
Washington follows it completely, as far as I can see. It's easy if you only have a few routes...
Quote from: Brandon on April 19, 2013, 12:29:41 PM
There is, effectively, already a 4di: I-H201, if you consider the 'H' as part of the number.
I'm looking at I-H201, and I'm only seeing three digits, two letters, and punctuation mark.
Quote from: briantroutman on April 17, 2013, 02:51:08 AM
So–multi-part question–what is your interpretation of the existing rule (for odd/even numbering), and in either a pragmatic or perfect world, what do you think it should be?
The odd/even first digit rule has been broken so many times it might as well not be a rule. It doesn't help anyone navigate.
There's only four first digits available for loop or link routes. It would have helped a little to use odd first digits for loops and links, and evens for spurs, so that there'd be five first digits available for the loops and links.
The lack of 3dis in California (at least) could have been avoided if California got more 2dis that they've asked for several times.
Quote from: kkt on April 22, 2013, 12:32:25 AM
Quote from: Brandon on April 19, 2013, 12:29:41 PM
There is, effectively, already a 4di: I-H201, if you consider the 'H' as part of the number.
I'm looking at I-H201, and I'm only seeing three digits, two letters, and punctuation mark.
So a 6di then? ;)
I'd kind of like to see all permutations of a 3di exhausted before they start to repeat. For example, there are three I-210s and two I-610s, but there are no I-810s.
Maybe it's somewhat impractical since some 2dis have enough 3dis to make repeats inevitable, but it always bugged me, especially when you get a number that shows up several times in close proximity like some of the x95s do.
Quote from: Brandon on April 19, 2013, 12:29:41 PM
Quote from: cpzilliacus on April 18, 2013, 08:47:08 PM
Quote from: briantroutman on April 17, 2013, 02:51:08 AM
We all know the numbering rules for Interstates, including at least a vague notion of the rules for 3DIs–first digit odd: spur, first digit even: loop/beltway.
Should 4DIs be allowed in states that "need" more 3DIs?
There is, effectively, already a 4di: I-H201, if you consider the 'H' as part of the number.
Isn't it really I-H-201, with the second hyphen removed so it can fit on shields?
The D stands for digit. Dumbasses.
Quote from: Roadsguy on April 22, 2013, 08:12:30 AM
Quote from: Brandon on April 19, 2013, 12:29:41 PM
Quote from: cpzilliacus on April 18, 2013, 08:47:08 PM
Quote from: briantroutman on April 17, 2013, 02:51:08 AM
We all know the numbering rules for Interstates, including at least a vague notion of the rules for 3DIs–first digit odd: spur, first digit even: loop/beltway.
Should 4DIs be allowed in states that "need" more 3DIs?
There is, effectively, already a 4di: I-H201, if you consider the 'H' as part of the number.
Isn't it really I-H-201, with the second hyphen removed so it can fit on shields?
How is it set up for the Hawai'i interstates anyway? I believe the "H" is a part of the number of the route, IIRC. The hyphen seems to appear on older signs, but not on newer ones.
Quote from: mrose on April 22, 2013, 04:21:26 AM
I'd kind of like to see all permutations of a 3di exhausted before they start to repeat. For example, there are three I-210s and two I-610s, but there are no I-810s.
Maybe it's somewhat impractical since some 2dis have enough 3dis to make repeats inevitable, but it always bugged me, especially when you get a number that shows up several times in close proximity like some of the x95s do.
One example here out west is I-580. I always felt that I-580 (NV) and I-580 (CA) were too close together for repeating 3DIs. Now IIRC, Nevada using I-5xx for its 2 3DIs fits is numbering for urban routes (NV-5xx), which does make sense. However, I feel that I-180 would fit better--despite being used 4 times already--as, unless California suddenly gets the itch to renumber CA-180, won't ever have an I-180.
However, I'd prefer to spread out 3DI numbers as much as possible, so I'd be inclined to use either I-780 or I-980, neither of which are terribly long, for Nevada's I-580.
Quote from: cpzilliacus on April 21, 2013, 09:04:35 PM
If PennDOT and PTC want to retain the abomination known as Breezewood, then FHWA should have I-70 re-routed by way of present-day I-68 and Pa. 43.
Considering that the Mon-Fayette Expressway was one of those cart-before-the-horse plans to stimulate economic development by building a freeway, adding a well-known cross-country Interstate designation might be a way to get a few cars on the road. So far, according to the Post-Gazette, the traffic hasn't materialized. http://bit.ly/ZgVT3q (http://bit.ly/ZgVT3q)
Quote from: Rover_0 on April 22, 2013, 01:40:10 PM
One example here out west is I-580. I always felt that I-580 (NV) and I-580 (CA) were too close together for repeating 3DIs. Now IIRC, Nevada using I-5xx for its 2 3DIs fits is numbering for urban routes (NV-5xx), which does make sense. However, I feel that I-180 would fit better--despite being used 4 times already--as, unless California suddenly gets the itch to renumber CA-180, won't ever have an I-180.
However, I'd prefer to spread out 3DI numbers as much as possible, so I'd be inclined to use either I-780 or I-980, neither of which are terribly long, for Nevada's I-580.
Apparently, the entire concept of 3DIs is so foreign to the people of Reno that a local newscast ran a story explaining what a 3DI is and why a section of US 395 was being designated as one. http://bit.ly/11wmgSD (http://bit.ly/11wmgSD)
Down in the comments below the video, one person said "Hey, I thought 580 was in California..." Probably a sign of how the Interstate numbering system (sadly) is meaningless to anyone except DOT officials and roadgeeks.
Quote from: briantroutman on April 22, 2013, 04:58:12 PM
Apparently, the entire concept of 3DIs is so foreign to the people of Reno that a local newscast ran a story explaining what a 3DI is and why a section of US 395 was being designated as one. http://bit.ly/11wmgSD (http://bit.ly/11wmgSD)
Down in the comments below the video, one person said "Hey, I thought 580 was in California..." Probably a sign of how the Interstate numbering system (sadly) is meaningless to anyone except DOT officials and roadgeeks.
I'm not surprised. Interstates are supposed to be a national system, and yet there may be many different routes with the same number? How can this not confuse people?
I've said it before, but I would be in favor of completely abandoning any parent/child relationships in route numbering. For all I care, a spur of I-55 can be numbered I-923; in fact, that would be less confusing to me than encountering I-155, I-255, I-355, et seq, and trying to figure out which is which. My only real beef with 3-digit routes is that I think they should be shorter than two-digit routes; there are several two-digit Interstates that are shorter than I-135 in Kansas (yes, I know it wasn't always numbered that).
Quote from: Rover_0 on April 22, 2013, 01:40:10 PM
One example here out west is I-580. I always felt that I-580 (NV) and I-580 (CA) were too close together for repeating 3DIs. Now IIRC, Nevada using I-5xx for its 2 3DIs fits is numbering for urban routes (NV-5xx), which does make sense. However, I feel that I-180 would fit better--despite being used 4 times already--as, unless California suddenly gets the itch to renumber CA-180, won't ever have an I-180.
However, I'd prefer to spread out 3DI numbers as much as possible, so I'd be inclined to use either I-780 or I-980, neither of which are terribly long, for Nevada's I-580.
It's tough for me to think two I-580s, in two different states, whose exits are about 200 miles apart, would be a cause of confusion... Perhaps that is my roadgeek knowledge factoring in. Aren't there some same-number 3DIs that are much closer?
Quote from: briantroutman on April 22, 2013, 04:58:12 PM
Apparently, the entire concept of 3DIs is so foreign to the people of Reno that a local newscast ran a story explaining what a 3DI is and why a section of US 395 was being designated as one. http://bit.ly/11wmgSD (http://bit.ly/11wmgSD)
Down in the comments below the video, one person said "Hey, I thought 580 was in California..." Probably a sign of how the Interstate numbering system (sadly) is meaningless to anyone except DOT officials and roadgeeks.
I don't think it was the concept of a 3DI that was foreign to Reno. It was the fact that the I-580 designation was newly signed, and was being signed
in place of (not alongside) US 395 shields. The community has known the highway as US 395 for a long time, so to see US 395 shields disappear (as was especially the case on 'freeway entrance' and related signs on the cross streets) prompted some confusion--I'm still not sure why NDOT did that.
I always looked at the even/odd 3dis in how they relate to the city that they serve and not so much how they interact with other interstates. Granted, there are always going to be exceptions to this (I-355 comes to mind) but you can reasonably expect an even number to be at least a bypass or beltway of the city. The first digit should reflect what the traffic is expected to do whether the highway will feed traffic in/out of an area or bypass the area all together.
Let me give you an example of what I mean. Take Milwaukee. There is I-794 and I-894. I-794 acts more of as a feeder between I-94/43 and the Lakefront so an odd number makes sense. I-894 is a certainly bypass for traffic going say from Kenosha to Madison or Fond du Lac. If the northern part of the bypass was ever built to meet back with I-43 in the north suburbs, it would still be reasonable to call that extension I-894 because it completes the bypass. Some would argue that you need a new number for that if it ever happened but IMO that would be a complete waste of a number, just like what happened in Minneapolis does with I-494 and I-694. That should have been one number.