This is coming from the I-335 Des Moines thread (https://www.aaroads.com/forum/index.php?topic=4584.0) - discussion of where Interstate (or US) numbers were skipped and why. Discussion there starts with I-335 and I-710 (CA). I'll add one: In Quebec, there are two A-440s and A-540s. But A-840 and A-940 are unused numbers. Why not put those over in Quebec City instead of duplicating numbers from Montreal? (The Montreal A-440 doesn't even come close to meeting A-440, and may as well be an X25.) Then you also have A-955 without a 755 or 555 and a 973 without a 773.
Then you have Wisconsin which inexplicably goes straight to I-794 and I-894 skipping everything else lower down.
Quote from: Brandon on June 01, 2011, 07:47:36 PM
Then you have Wisconsin which inexplicably goes straight to I-794 and I-894 skipping everything else lower down.
Nothing inexplicable about that. You have a lot of I-94 in Wisconsin heading east from Minnesota. It's not inconceivable that Eau Claire or Madison may end up with a I-X94 route at some point.
I'd imagine it's a combination of future expansion, as well as because some spurs work well when numbered a certain way. (I-580 in CA comes to mind, because it literally connects I-5 to I-80.)
If I'm not mistaken, I-580 and I-505 each represent the first ever signed odd x80 and x05 routes in California. Both were either signed as or planned as I-5W pre-1964 though, so that may explain the digits (and both routes never return to their parents so they are ostensible spurs).
The original 105 was an unsigned segment of US 101/Santa Ana Freeway from 1964-1968 between the San Bernardino Freeway and the East Los Angeles Interchange; I-305 was created in 1982 as an unsigned designation for former I-80 (current US 50/Business 80) between West Sacramento and Route 99 in Sacramento.
As for I-580...I-180 has never been assigned to a signed road due to the existence of state route 180 in Fresno (and I-180 was only temporarily used for the ex-Route 17 Richmond Bridge freeway before it became part of an I-580 extension). But I-380 came about in 1968 as a redesignation of then-Route 186, several years after 580 was assigned...
QuoteI'd imagine it's a combination of future expansion, as well as because some spurs work well when numbered a certain way. (I-580 in CA comes to mind, because it literally connects I-5 to I-80.)
I'm fairly certain that was the rationale for I-705 in Tacoma as well- it was an extension of SR 7 off of I-5.
I had figured that Quebec avoided numbering autoroutes in the 1xx, 2xx, and 3xx range because they use those numbers for ordinary provincial routes.
In the US, skipping of a lower number is often a sign of a route that was planned but never built. For example, Connecticut has I-291 and I-691 but I-491 never got off the drawing board.
Quote from: JREwing78 on June 01, 2011, 07:54:09 PM
Quote from: Brandon on June 01, 2011, 07:47:36 PM
Then you have Wisconsin which inexplicably goes straight to I-794 and I-894 skipping everything else lower down.
Nothing inexplicable about that. You have a lot of I-94 in Wisconsin heading east from Minnesota. It's not inconceivable that Eau Claire or Madison may end up with a I-X94 route at some point.
Yeah, but you don't have to have a progression of 3dis across the state. I-894 could come well further west than I-294.
Could it be a deference to other states? At least with the even numbers- Minneapolis has 494 and 694 while Chicago has 294. Those cities are all significant to Wisconsinites and near Wisconsin.
I suspect that's the reason Kansas doesn't overlap any interstate numbers with Missouri except where it's the same interstate
Quote from: corco on June 01, 2011, 10:26:52 PM
Could it be a deference to other states? At least with the even numbers- Minneapolis has 494 and 694 while Chicago has 294. Those cities are all significant to Wisconsinites and near Wisconsin.
I suspect that's the reason Kansas doesn't overlap any interstate numbers with Missouri except where it's the same interstate
What about 470? :spin:
QuoteWhat about 470?
I completely forgot about 470 and that pretty much nixes that theory
Both of Nevada's spur interstates are 5's: I-515 and I-580. My theory is that it somehow relates to the numbering scheme of Nevada's state routes from the 70s--500s & 600s numbers being assigned to urban state routes, and the routes being obvious spurs.
Nevada's (future) Interstate loop took the first available number: I-215. This freeway went through initial planning much later on, though.
I seem to recall reading somewhere that Charlotte's Outerbelt is numbered I-485 in deference to I-285 around Atlanta even though the two cities are about three hours apart (with a third state in between as well). I suppose one could argue that I-485 makes something of a progression since you have the aforementioned I-285, then I-185, I-385, and I-585 in South Carolina. I don't really understand I-985 in Georgia, though. Georgia doesn't seem too concerned with duplication given that there's an I-185 near Columbus, but I guess I-985 is a lot closer to South Carolina's three I-x85s so a duplication there might have been more of a problem. Still, I-785 was available and was skipped.
Slight threadjack in view of the discussion of duplications being a reason for number selection–my favorite instance of a road number being duplicated is I-68 in Maryland. There is a MD-68 some distance east of there at Clear Spring. When you go through the Clear Spring area heading west on I-70, you see the sign shown at the link below. I roll my eyes every time I see it because to me it underscores how stupid some drivers are.
http://maps.google.com/?ie=UTF8&ll=39.653086,-77.907186&spn=0.024484,0.066047&z=15&layer=c&cbll=39.653113,-77.90743&panoid=t6VZ9lc9ierBLxMPLYF8eA&cbp=12,295.58,,0,8.77
Does anyone know why the state of Washington skipped some spur route numbers (511, 517, 521, 533, 535, 541, 545, etc.)?
QuoteDoes anyone know why the state of Washington skipped some spur route numbers (511, 517, 521, 533, 535, 541, 545, etc.)?
517 was proposed to be a route but was decommissioned in the 1992 decommissioning before it was ever officially commissioned. Same with 511.
As for the others, I would suspect it follows the possible expansion theory, since those spur numbers usually increase from south to north or west to east.
This thread seems like a good place to note that I-340 has never been used, yet we already have I-540 in Arkansas (future I-49) and in North Carolina!
I'm surprised that when the Baltimore I-170 was canceled, that that number wasn't recycled for what is now I-370 (much as I-880 was reused in California after the Business 80/I-80 switcharound in 1982, showing up in the Bay Area from 1984 onwards).
In Minnesota, the never-built first spur of I-35 (I-335 in Minneapolis) and the first spur of I-94 (I-394 west of Minneapolis) each don't start at 1, but at 3. For that matter, I-94 does not have any duplicated even-number loop routes! (Had I-494 been built in Chicago, this wouldn't be the case however.)
QuoteIn Minnesota, the never-built first spur of I-35 (I-335 in Minneapolis) and the first spur of I-94 (I-394 west of Minneapolis) each don't start at 1, but at 3.
With the exception of MN 62, MnDOT doesn't like route duplication. I-335 and I-394 were numbered as such because then-MHD (Minnesota Highway Department, precursor to MnDOT) already had a MN 135 and MN 194, which themselves had previously been MN 35 and MN 94 respectively...they were renumbered when the Interstates first came about.
Same reason why the Twin Cities Beltline starts with I-494...MHD already had a MN 294.
Quote from: corco on June 01, 2011, 10:26:52 PM
Could it be a deference to other states? At least with the even numbers- Minneapolis has 494 and 694 while Chicago has 294. Those cities are all significant to Wisconsinites and near Wisconsin.
The x94 spurs in Milwaukee were almost certainly chosen to differentiate them from Chicagoland x94's. If Chicago's taking low number spurs, we're going to start near the top.
This is just a total coincidence, but if there were spurs into Racine and Kenosha; and the airport spur in Milwaukee was an interstate; and if you started numbering these odd spurs at the border and worked your way north, 794 would be 794.
194 - Kenosha
394 - Racine
594 - airport spur
794 - same as reality
It might explain why we'd grab the highest even spur, but only the second highest odd spur for Milwaukee. Although I get the impression that a 9xx is like an interstate spur of last resort. So taking that into account, 794 would be the 'better' choice.
Quote from: triplemultiplex on June 02, 2011, 03:24:06 PM
a 9xx is like an interstate spur of last resort.
Except 985...
...And 990, and 905, and 980, and (unsigned) 910.
There's nothing "last resort" about 9xx, it would just logically be the northernmost and easternmost spur assigned, right? As already stated, larger states that have used up 1xx, 3xx, 5xx and 7xx would thus have to make do with 9xx.
Of course, some 3di that should be signed as spurs, like I-476 in Pennsylvania, are not.
Not necessarily - not all states number 3dis based on geographic location. Most, to my knowledge anyway, choose a number that has specific meaning, like 580 connecting 5 to 80, or just number them sequentially. For example, VDOT appears to follow this scheme, at least as far as I can tell. There is a 195, a 295, a 495, and an 895 (albeit a state route, this is still an interstate-grade freeway originally planned to carry an interstate 895 shield) (695 probably skipped due to the D.C. 695), as well as a 164 (albeit a state route, this is still an interstate-grade freeway that could carry an interstate 164 shield), 264, 464 (whose proposed number was 364), 564, and 664, and a 381 and 581, with 181 presumably skipped because of Tennessee's.
Quote from: 1995hoo on June 02, 2011, 10:03:43 AM
I seem to recall reading somewhere that Charlotte's Outerbelt is numbered I-485 in deference to I-285 around Atlanta even though the two cities are about three hours apart (with a third state in between as well). I suppose one could argue that I-485 makes something of a progression since you have the aforementioned I-285, then I-185, I-385, and I-585 in South Carolina. I don't really understand I-985 in Georgia, though. Georgia doesn't seem too concerned with duplication given that there's an I-185 near Columbus, but I guess I-985 is a lot closer to South Carolina's three I-x85s so a duplication there might have been more of a problem. Still, I-785 was available and was skipped.
Slight threadjack in view of the discussion of duplications being a reason for number selection–my favorite instance of a road number being duplicated is I-68 in Maryland. There is a MD-68 some distance east of there at Clear Spring. When you go through the Clear Spring area heading west on I-70, you see the sign shown at the link below. I roll my eyes every time I see it because to me it underscores how stupid some drivers are.
http://maps.google.com/?ie=UTF8&ll=39.653086,-77.907186&spn=0.024484,0.066047&z=15&layer=c&cbll=39.653113,-77.90743&panoid=t6VZ9lc9ierBLxMPLYF8eA&cbp=12,295.58,,0,8.77
It seems that GA will defer to other states. 275 is in Tampa/St Pete and then 475 @ Macon and 675 in Atlanta. It seems that there was some pattern with increasing spur numbers ( ie 295 in Richmond, 495 Washington and 695 in Baltimore) but in the Northeast almost every state has a 195 and 295
Michigan's I-x96s are geographically numbered. I-196 is the westernmost, I-296 is the even downtown bypass for Grand Rapids, I-496 is the even loop for Lansing and I-696 is the even bypass for Detroit.
The I-x75s are also in order, although I-175 was skipped. I-275 is the downtown bypass for Detroit, I-375 is the spur in downtown Detroit, I-475 is next around Flint and I-675 is around Saginaw.
Quote from: JREwing78 on June 01, 2011, 07:54:09 PM
Quote from: Brandon on June 01, 2011, 07:47:36 PM
Then you have Wisconsin which inexplicably goes straight to I-794 and I-894 skipping everything else lower down.
Nothing inexplicable about that. You have a lot of I-94 in Wisconsin heading east from Minnesota. It's not inconceivable that Eau Claire or Madison may end up with a I-X94 route at some point.
There's also the possibility that Wisconsin didn't want another I-294 or I-494 (I-894 was posted before 1979 right?) that close to the ones in Chicagoland. As for speculation on I-794, there may have been a desire to extend the designation into Illinois along the cancelled Lake Freeway. At one time, given the map on Kurumi's site, and the state route numberings, it appears 194, 394, and 594 could have strongly considered for use in Chicagoland.
http://www.kurumi.com/roads/3di/chicago.html (http://www.kurumi.com/roads/3di/chicago.html)
EDIT: There also may be the skipping of I-164 in Illinois, since I-564 is proposed for the I-64 to new bridge route once the bridge to I-55 east of IL 203 roadway is complete. I-364 is likely being skipped due to the proximity of MO 364 (which is not MO 164 because supposedly MoDOT thinks 1 is confused with I too much).
Quote from: jwolfer on June 03, 2011, 11:55:46 AMIt seems that there was some pattern with increasing spur numbers ( ie 295 in Richmond, 495 Washington and 695 in Baltimore) but in the Northeast almost every state has a 195 and 295
Of I-95's ten northeastern states (Maryland, Delaware, Pennsylvania, New Jersey, New York, Connecticut, Rhode Island, Massachusetts, New Hampshire, Maine), five have a 195 (50%) and seven have a 295 (70%), with Pennsylvania, Connecticut, and New Hampshire having neither. Pennsylvania and New Hampshire have no x95s, Connecticut has only 395... no doubt in deference to existing CT 195 - which was CT 95 before the interstate era.
What's interesting is that while I-95 has more children than any other interstate, there is no I-995 anywhere, and of all the states it passes through only Maryland has used up every other number. I-95 passes through a lot of states, thanks to them being small in the northeast... (though it may be noted that there are eight children of I-95 in New England, 2 each of 195, 295, 395, and 495)
i think it is mainly because of the proximity to other 3dis in other states. But probably more like a "radius range" of distance from one as in the case of 470 in KC and Topeka. Think of it like having 2 or 3 news radio stations that are broadcasting traffic reports. Most AM stations range is roughly 70-100 miles. Some have a bigger signal, such as 720 WGN, 780 WBBM and 670 WSCR (all in Chicago). Those 3 i have no problem picking up at my grandmothers in central WI. I also have no problem picking up at home 620 WTMJ in Milwaukee even though i am 107 mi from the tower. I once picked up between Toledo and Algona, IN the Lions, Browns, Bengals, Colts, Bears, and Packers flagship stations on normal AM radio. But i digress.
Just a thought.
Arkansas has I-540, but no 140 or 340. Also has 440, but no 240... maybe because Memphis has one less than 3 hours away?
To my knowledge I-340 doesn't exist anywhere.
Michigan has 275, 375, 475, and 675 off of I-75, 196, 296, 496, and 696 off of I-96, and 194 off of I-94. I have no idea why 175 was skipped, as there was not an M-175 (but M-75 still exists within 30 miles of I-75).
Quote from: Scott5114 on June 01, 2011, 10:47:59 PM
Quote from: corco on June 01, 2011, 10:26:52 PM
Could it be a deference to other states? At least with the even numbers- Minneapolis has 494 and 694 while Chicago has 294. Those cities are all significant to Wisconsinites and near Wisconsin.
I suspect that's the reason Kansas doesn't overlap any interstate numbers with Missouri except where it's the same interstate
What about 470? :spin:
Speaking of that, Kansas did skip 270. Maybe it's because Colorado and Missouri already have 270, but I've long wondered whether Kansas would use 270 if the future South Lawrence Trafficway (K-10) was made into an Interstate.
Quote from: stridentweasel on June 07, 2011, 09:30:37 PM
Speaking of that, Kansas did skip 270. Maybe it's because Colorado and Missouri already have 270, but I've long wondered whether Kansas would use 270 if the future South Lawrence Trafficway (K-10) was made into an Interstate.
But Kansas may have been trying to avoid duplication with US 270, which used to go further into the state.
that leads to a good question - are there any duplicated three-digit interstate/US pairs in any state?
Quote from: agentsteel53 on June 07, 2011, 10:21:23 PM
that leads to a good question - are there any duplicated three-digit interstate/US pairs in any state?
That should be impossible, as the same avoidance of 2 digit interstate/US pairs in the same state should prevent any duplicate 3 digit numbers as well. But with so many later add-ons in both systems, it might be possible. For example, if I-20 had a an I-220 loop in South Carolina and US 220 extended a little further into that state, then you'd have one example. But I can't think of any examples that actually exist.
It's not just 'later add-ons' - US 830, for example, was in Washington since 1926, but US 30 has never entered the state.
In OH, the only three-digit x90 is the brief I-490 segment near downtown Cleveland. It was mentioned before that this was originally to be named I-290 and continue as a connection to I-271 on the east side of Cleveland. But why was it changed to I-490 is still somewhat of a mystery.
My only theory is that since SR-2 multiplexes with I-90 on either side of Cleveland quite visibly, that adding a bona-fide 290 freeway to a freeway system that has a 90/2 or 2/90 freeway would have caused some confusion.
And then there is Buffalo's I-990, but I don't think there was much choice in what was left in available x90s either. Nonetheless, it does give Buffalo the honor of having the highest-numbered interstate.
Quote from: Revive 755 on June 07, 2011, 10:18:28 PM
Quote from: stridentweasel on June 07, 2011, 09:30:37 PM
Speaking of that, Kansas did skip 270. Maybe it's because Colorado and Missouri already have 270, but I've long wondered whether Kansas would use 270 if the future South Lawrence Trafficway (K-10) was made into an Interstate.
But Kansas may have been trying to avoid duplication with US 270, which used to go further into the state.
I completely overlooked US 270 (oops).
Quote from: thenetwork on June 08, 2011, 10:20:46 AM
And then there is Buffalo's I-990, but I don't think there was much choice in what was left in available x90s either. Nonetheless, it does give Buffalo the honor of having the highest-numbered interstate.
Actually they had NO choice as all the other x90s are used up.
| 190, 290 | Buffalo |
| 390, 490, 590 | Rochester |
| 690 | Syracuse |
| 790 | Utica |
| 890 | Schenectady |
Quote from: stridentweasel on June 08, 2011, 04:07:16 PM
I completely overlooked US 270 (oops).
So did I, probably because it barely makes it to Kansas. Still, that would've made a 3-digit interstate/US pair possible.
So why did Indiana go with 469 for Fort Wayne? Is there an IN-269 they didn't want to duplicate?
Personally, I like the idea of vaguely reserving numbers for future highways that might be a better fit, but I don't think planners in the Interstate Era had that much foresight.
As for progressions, the idea of geographic progression of child Interstates from south/west to north/east is interesting, but I'd prefer a system where the lowest 3dI numbers are reserved for long, rural routes and higher ones for shorter urban branches. This more or less holds true in Ohio, though I'm not sure that was the original intention, and if it was, they could have done it better.
Quote from: vtk on June 29, 2011, 10:16:22 PM
So why did Indiana go with 469 for Fort Wayne? Is there an IN-269 they didn't want to duplicate?
Personally, I like the idea of vaguely reserving numbers for future highways that might be a better fit, but I don't think planners in the Interstate Era had that much foresight.
As for progressions, the idea of geographic progression of child Interstates from south/west to north/east is interesting, but I'd prefer a system where the lowest 3dI numbers are reserved for long, rural routes and higher ones for shorter urban branches. This more or less holds true in Ohio, though I'm not sure that was the original intention, and if it was, they could have done it better.
Probably because InDOT wanted to make sure that if & when I-69 was to be extended past Indianapolis, that they would have at least 3 x69 routes available for the use of future bypasses and spurs. If they wanted to be totally safe, they should've called the Ft. Wayne bypass I-669 or I-869, since it would give south & central Indiana even more lower numbers to use and it would be extremely doubtful that there would ever be another I-x69 loop or spur north of Ft. Wayne in the Hoosier state, being so close to Michigan.
Quote from: thenetwork on June 30, 2011, 05:53:27 PM
Quote from: vtk on June 29, 2011, 10:16:22 PM
So why did Indiana go with 469 for Fort Wayne? Is there an IN-269 they didn't want to duplicate?
Personally, I like the idea of vaguely reserving numbers for future highways that might be a better fit, but I don't think planners in the Interstate Era had that much foresight.
As for progressions, the idea of geographic progression of child Interstates from south/west to north/east is interesting, but I'd prefer a system where the lowest 3dI numbers are reserved for long, rural routes and higher ones for shorter urban branches. This more or less holds true in Ohio, though I'm not sure that was the original intention, and if it was, they could have done it better.
Probably because InDOT wanted to make sure that if & when I-69 was to be extended past Indianapolis, that they would have at least 3 x69 routes available for the use of future bypasses and spurs. If they wanted to be totally safe, they should've called the Ft. Wayne bypass I-669 or I-869, since it would give south & central Indiana even more lower numbers to use and it would be extremely doubtful that there would ever be another I-x69 loop or spur north of Ft. Wayne in the Hoosier state, being so close to Michigan.
That makes sense with the assumption that Indiana specifically wanted its 3dI families to have a geographic progression. That certainly seems to be the case in Michigan, but I hadn't heard of any other states trying to do the same thing, and I'm not sure it's safe to assume that pattern was meant to be followed everywhere. Some people in this thread seem to be assuming that, but as far as I'm concerned, such intention hasn't been established for any state other than Michigan. (As for Michigan, I believe I heard of this from Chris Bessert at a roadgeek meet once, and I don't believe it was intended to represent any other states.)
NY seems to do it too (more or less) but there's no reason it has to be done. Just look at I-990.
Quote from: deanej on July 01, 2011, 01:49:07 PM
NY seems to do it too (more or less) but there's no reason it has to be done. Just look at I-990.
Well, 990 came along after the other eight x90s were neatly arranged in numerical order from Buffalo to Schenectady, didnt it?
Yes, but the point is there's no rule saying that 3dis have to go in numeric order across the state.
A related question is why some three-digit Interstates do not receive lower first digits. Taking the example of I-35 in Kansas, why do we not have the following number assignments in lieu of what actually exists:
* I-235 beltway around Kansas City metropolitan area (presently I-435)
* I-435 connector between I-29 in Missouri and I-35 in Kansas (presently I-635)
* I-635 Wichita western bypass (presently I-235)
Quote from: deanej on July 02, 2011, 12:24:02 PM
Yes, but the point is there's no rule saying that 3dis have to go in numeric order across the state.
You could argue similarly that the Interstates don't form a grid because of I-99. There probably was some sort of 'rule' when numbers were assigned, at least in some states, but newly-numbered routes had to get the next available number. The same was true for three-digit U.S. Routes: 41 had, from north to south, 141 to 441, and 541 later continued the progression, but 641 went in the middle between 141 and 241.
Quote from: NE2 on July 02, 2011, 01:42:50 PM
Quote from: deanej on July 02, 2011, 12:24:02 PM
Yes, but the point is there's no rule saying that 3dis have to go in numeric order across the state.
You could argue similarly that the Interstates don't form a grid because of I-99. There probably was some sort of 'rule' when numbers were assigned, at least in some states, but newly-numbered routes had to get the next available number. The same was true for three-digit U.S. Routes: 41 had, from north to south, 141 to 441, and 541 later continued the progression, but 641 went in the middle between 141 and 241.
The Interstates never really did form a strict grid. If they did, then no two Interstates of the same parity would ever have crossed each other. Given the existence of so many diagonal routes, it would be asinine to impose such a constraint on the system. I-99 doesn't really break the grid any more than it was already broken.
Read this again:
Quote from: deanej on July 02, 2011, 12:24:02 PM
But the point is there's no rule saying that 3dis have to go in numeric order across the state.
You seem to be under the impression that this
was a rule in the past, everywhere, which has necessarily been broken by new additions. In some states, there is evidence for this, but I certainly don't believe it to be universally true. Besides this thread, the only time I'd heard of such a progression concept was in reference to Michigan, and, now that I think about it, possibly with the 3dUS highways. But 3dUS highways and 3dI loops & spurs are quite different in nature.
Maybe an answer to the following question can inject some needed historical insight: Was the numbering of 3-digit Interstates from the Yellow Book plan (original 41,000 miles) done by AASHO, or did AASHO simply approve the numbers that individual states submitted?
Quote from: vtk on July 02, 2011, 06:18:10 PM
The Interstates never really did form a strict grid. If they did, then no two Interstates of the same parity would ever have crossed each other. Given the existence of so many diagonal routes, it would be asinine to impose such a constraint on the system. I-99 doesn't really break the grid any more than it was already broken.
Well, yes, but everything was at least partially in place until I-80N became I-84.
Quote from: vtk on July 02, 2011, 06:18:10 PM
Maybe an answer to the following question can inject some needed historical insight: Was the numbering of 3-digit Interstates from the Yellow Book plan (original 41,000 miles) done by AASHO, or did AASHO simply approve the numbers that individual states submitted?
The latter: http://cahighways.org/097-104.html#102
Quote from: NE2 on July 02, 2011, 06:30:36 PMWell, yes, but everything was at least partially in place until I-80N became I-84.
I-71?, I-85? I agree that removing suffixed routes messed the grid up a bit, but it was broken before that.
Quote from: english si on July 02, 2011, 07:31:31 PM
Quote from: NE2 on July 02, 2011, 06:30:36 PMWell, yes, but everything was at least partially in place until I-80N became I-84.
I-71?, I-85? I agree that removing suffixed routes messed the grid up a bit, but it was broken before that.
Part of I-71 is between I-65 and I-75. Part of I-85 is between I-75 and I-95. Hence both are partially in place.
Quote from: NE2 on July 02, 2011, 06:30:36 PM
Quote from: vtk on July 02, 2011, 06:18:10 PM
Maybe an answer to the following question can inject some needed historical insight: Was the numbering of 3-digit Interstates from the Yellow Book plan (original 41,000 miles) done by AASHO, or did AASHO simply approve the numbers that individual states submitted?
The latter: http://cahighways.org/097-104.html#102
Well then, obviously California wasn't trying to make geographically-ordered 3dIs.
Quote from: Steve on June 01, 2011, 07:15:44 PM. I'll add one: In Quebec, there are two A-440s and A-540s. But A-840 and A-940 are unused numbers. Why not put those over in Quebec City instead of duplicating numbers from Montreal? (The Montreal A-440 doesn't even come close to meeting A-440, and may as well be an X25.) Then you also have A-955 without a 755 or 555 and a 973 without a 773.
There'll be one less A-540 soon. The Montreal A-540 will be renumbered as a part of A-30 extension
http://www.mtq.gouv.qc.ca/portal/page/portal/Librairie/Publications/fr/grands_projets/a30_parachevement/a-30_carte_sorties_grande.pdf
Quote from: deanej on July 02, 2011, 12:24:02 PM
Yes, but the point is there's no rule saying that 3dis have to go in numeric order across the state.
My point was, apparently New York did try to do that, at least with I-90; the fact that 990 is out of order is explainable by the fact that it was added after the others were in place.
It's hard to say if Georgia was explicitly trying to have a progression across the state, but if so it's worked out reasonably well - the only one "out of place" is I-675, which wasn't added until the 1980s and is between I-475 and I-575. Even the proposed-but-never-built Interstates would fit in such a progression, with 175 being south of 475, 420 being west of 520, and the originally proposed 475 (not the one in Macon) being south of 575; 485, I believe, would've been entirely inside 285, so I suppose that also fits in a way.
Quote from: J N Winkler on July 02, 2011, 01:19:47 PM
A related question is why some three-digit Interstates do not receive lower first digits. Taking the example of I-35 in Kansas, why do we not have the following number assignments in lieu of what actually exists:
* I-235 beltway around Kansas City metropolitan area (presently I-435)
* I-435 connector between I-29 in Missouri and I-35 in Kansas (presently I-635)
* I-635 Wichita western bypass (presently I-235)
What would be the benefit to this compared to the current setup? As it stands, going from south to north on I-35 (the same way the mileposts are reckoned), you see I-135, I-235, I-335, I-435, I-635, in that order.
Quote from: vtk on July 02, 2011, 06:18:10 PM
You seem to be under the impression that this was a rule in the past, everywhere, which has necessarily been broken by new additions. In some states, there is evidence for this, but I certainly don't believe it to be universally true. Besides this thread, the only time I'd heard of such a progression concept was in reference to Michigan, and, now that I think about it, possibly with the 3dUS highways. But 3dUS highways and 3dI loops & spurs are quite different in nature.
Where did you get that impression from? The reason I used the x90s is because I'm not familiar with any other example where the 3dis aren't entirely in order. There was never any rule, the states just kinda did it. Perhaps MA or VT could be used as examples, with 3dis out of place form where one would expect for this kind of rule, but in the absence of additional 3dis they're still in order.
Quote from: Michael in Philly on July 02, 2011, 09:58:57 PM
Quote from: deanej on July 02, 2011, 12:24:02 PM
Yes, but the point is there's no rule saying that 3dis have to go in numeric order across the state.
My point was, apparently New York did try to do that, at least with I-90; the fact that 990 is out of order is explainable by the fact that it was added after the others were in place.
With I-87 as well. 187, 287, 387, and 487 were all in the NYC area. All would have been in place with each other, with the exception of the first 487 (Cross-Westchester Expressway) which was south (actually east) of 287, although 287 was locked into place by New Jersey. Then 587 is in Kingston, and proposed 687 and current 787 are both in Albany.
Regarding the "is this a rule?", my understanding is that the states choose the 3di number when they apply to AASHO, and they say yay or nay. I think the answer is generally no, but some states chose to follow such a guideline when they were picking numbers.
Quote from: Scott5114 on July 03, 2011, 01:14:07 AMWhat would be the benefit to this compared to the current setup? As it stands, going from south to north on I-35 (the same way the mileposts are reckoned), you see I-135, I-235, I-335, I-435, I-635, in that order.
The feature ("benefit" is probably too strong a term) of the numbering I outlined is that the larger metropolitan area gets the lower three-digit numbers. It could be argued that, particularly in situations where potential three-digit routes outnumber possible choices for three-digit Interstate route number, it makes more sense to allocate numbers first to the large metropolitan areas since it is in those places that the traffic demand for Interstate-type facilities is most firmly established.
In actuality, I suspect Kansas (with Missouri's cooperation and BPR's approval) allocated three-digit numbers in the order in which the relevant routes were planned and built, without operating a number reservation scheme. I-235 was mostly finished (Turnpike interchange to Broadway) by 1962, while I think construction on I-435 and I-635 started a little later. At the beginning of original Interstate construction, I suspect few if any states tried reserving three-digit route numbers by size of metropolitan area because it would have taken considerable foresight to predict the numerous ways in which the Interstate network would be expanded beyond the original plan.
BTW, the neat milepost ordering of three-digit routes for I-35 in Kansas you outline is, to an extent, artificial. Originally, in 1962, there was no I-135. I-235 interchanged directly with the Turnpike; I-35W came along later and its numbering change to I-135 came still later. I-335 is an artifact of the 65 MPH speed law.
Quote from: Kacie Jane on July 03, 2011, 09:58:10 PM
Quote from: Michael in Philly on July 02, 2011, 09:58:57 PM
Quote from: deanej on July 02, 2011, 12:24:02 PM
Yes, but the point is there's no rule saying that 3dis have to go in numeric order across the state.
My point was, apparently New York did try to do that, at least with I-90; the fact that 990 is out of order is explainable by the fact that it was added after the others were in place.
With I-87 as well. 187, 287, 387, and 487 were all in the NYC area. All would have been in place with each other, with the exception of the first 487 (Cross-Westchester Expressway) which was south (actually east) of 287, although 287 was locked into place by New Jersey. Then 587 is in Kingston, and proposed 687 and current 787 are both in Albany.
Regarding the "is this a rule?", my understanding is that the states choose the 3di number when they apply to AASHO, and they say yay or nay. I think the answer is generally no, but some states chose to follow such a guideline when they were picking numbers.
I'd say there is no question that NYS intends to number 3dis in order, looking both at I-90 and I-87. And now there's evidence for it with I-81 as well: I-281 was changed long ago to I-481, as Syracuse is right in the middle of the route. And the new spur in Watertown is numbered 781, perhaps because it's so far north along the route; they could just as easily have gone with 181 or 381.
Other states like TN show a propensity for this: 240, 440, 640 from west to east. Any more?
I wonder if Tennessee and Virginia collaborated on the numbering of I-81's spurs. I-181 from Kingsport down to Johnson City; I-381 in Bristol, I-581 in Roanoke. Was Bristol considered to be too close to Tennessee's I-181 to permit Virginia's use of that number for the Bristol connector?
It obviously didn't factor into numbering I-265 and I-275 in Tennessee and Kentucky.
I-364 was also never used in Virginia, although it was proposed for I-464. I think this is because there was a VA 364 already around, albeit well away from Hampton Roads, by the time I-564 was assigned.
Here in Texas (which has a surprising lack of 3dis for a state this big, with this many Interstate routes (four or five of which are major routes), and with as extensive a freeway network as we do.
There are only 6 in the whole state, two of which are secret unsigned routes. The signed routes are all beltways or semi-beltways which necessitates an even number spur. In their placement, however, it seems perfect. IH 110 is (while unsigned) in El Paso, right after entering Texas, 410 in San Antonio, 610 in Houston. The only silly one is the secret IH 345 in Dallas which is essentially a one mile extension of 45, which ends at IH 30. So if any 3dis are ever issued here in Houston or between Houston and Dallas, the numbers will be out of order.
Kinda not exactly what the topic discusses, but it does explain why the Dallas beltway is 635 and not 235. 235 is skipped in case there is ever a belt or bypass of, say, Austin or Waco.
820 is almost silly because it's not like Fort Worth is right near the TX/LA border. (Thankfully Tyler's loop will be a TX State Loop). 820 was more likely chosen because of Amon Carter's radio station though. And we all know 420 won't ever be chosen.
Louisiana's 3di's work nicely on I-10 as well. Other than hidden 910, all the spurs line up nicely (110-Baton Rouge, 310 NO west side, and 510 NO east.) The loops work too. 210 is in Lake Charles right near Texas, the planned 410 has been an idea for New Orleans and now for Baton Rouge, and 610 is downtown New Orleans.