What states have nonduplication rule for route numbers?

[TEG24601]

Indiana does have duplicates, however, these are largely due to discontinuities created by other routes being built and supplanting the original, or the *Non-BBC2 Word* removal of routes from within major cities.


AFAIK Washington, Oregon, California, and Idaho are anal about preventing duplication in the visible route numbers, except of course for 99/99W/99E for historical reasons.

[TheStranger]

Makes me wonder though, why not just have something like I-238 signed as I-180 but legislatively it exists as part of route 238?  Would that technically be a duplication in the eyes of the legislatures?...I would suspect not with all ye unsigned routes throughout the state.

I think the non-duplication thing is more a Caltrans push than a legislative one: no duplicate numbers means that there's no confusion as to what route refers to what, and the reduction of concurrencies in theory was supposed to simplify how much travelers would have to remember for navigation.

Of course, the I-15E/Route 194 and Business 80/Route 51 dual-designation situations subvert this to some degree.

I've always liked the system used elsewhere (particularly Massachusetts) where the numbered routes do not reflect state maintenance, but rather (generally) logical navigational routings.

[Brandon]

I do wonder about states that do have duplication, such as Texas... There is both a TX-10 and an Interstate 10. I suppose in those states, you simply always prefix the highway type when speaking.

In some of them, yes.  In Michigan, it is very common to us M-nn, US-nn, or I-nn when speaking, such as "Take M-96 to M-294 to I-94 to US-127".  Even in the UP, where one can hear "highway", it's "Highway M-28", or "Highway US-41".  In Illinois, not so much.  There, just plain "route" or "highway" can be heard.

[hbelkins]

Other Virginia duplications -- US and VA 13, and the infamous US/VA 33 which is a "kind of but not really" continuation, in the same vein as US and KY 79.

[english si]

*Non-BBC2 Word*

Err, odd cultural reference...

BBC2 is much more sweary than BBC1. It's also far more likely to have nudity - that more niche and artsy brief vs the populist brief of BBC1.

The third and fourth seasons of (the excellent) The Thick of It aired first on BBC2. (very NSFW - this is perhaps one of less OTT ones)
https://www.youtube.com/watch?v=i93-u39XV7I

But the c-word is always post-10pm, unlike news channels (Radio 4, and today SkyNews) where Jeremy Hunt's name seems to get mispronounced more often than not

[thenetwork]

Colorado is debatable -- especially when it comes down to CO-470 and E-470.  CO-470 is maintained by CDOT, while E-470 is a privately run Toll Road.  They also use different shields even though 470 is a continuous road skirting Denver on 3 sides.

Otherwise CO-25 became CO-55, CO-70 became CO-51 and CO-76 became CO-78 when their interstate counterparts were established.

[bulldog1979]

The lists given for Michigan duplicates are incomplete. Each 2dI has a corresponding 2dM someplace: I-69 and M-69, I-75 and M-75, I-94 and M-94, I-96 and M-96. Several of the 2dUSes have duplicates: US 8 and M-8, US 10 and M-10, US 24 and M-24, US 45 and M-45. Historically, US 25 and M-25, US 27 and M-27, US 33 and M-33, US 112 and M-112, US 131 and M-131 have also both existed at the same times. US 102 and M-102 have have also briefly existed at the same time in 1928; if not, it was a near miss by a matter of weeks. M-2 may have been used on the Jeffries Freeway service drives in the 1970s, duplicating US 2's number at that time.

In 1926, the state renumbered highways and avoided duplicating US Highway numbers except where highways were renumbered as implied continuations of new US Highways: US 24 and M-24 had a common terminus in Pontiac, and US 131 and M-131 had a common terminus near Fife Lake. Other later changes resulted in M-25 as an extension of US 25 in the Thumb. Later M-10 was used for former sections of US 10, and M-27 was assigned to a former section of US 27. So over the years, any internal rule against duplication was relaxed and then disregarded completely by the time the Interstates were designated.

[Eth]

GA: I-20 and GA 20, which intersect.

US 27 and GA 27 also intersect. Most US and I-routes below 400 have state route duplicates, and so does I-520.

[jakeroot]

Colorado is debatable -- especially when it comes down to CO-470 and E-470.  CO-470 is maintained by CDOT, while E-470 is a privately run Toll Road.  They also use different shields even though 470 is a continuous road skirting Denver on 3 sides.

Is the entire route referred to simply as "the 470" or "Highway 470"? Or do locals differentiate between the two? Just a question, not necessarily related to the topic at hand.

[Max Rockatansky]

The lists given for Michigan duplicates are incomplete. Each 2dI has a corresponding 2dM someplace: I-69 and M-69, I-75 and M-75, I-94 and M-94, I-96 and M-96. Several of the 2dUSes have duplicates: US 8 and M-8, US 10 and M-10, US 24 and M-24, US 45 and M-45. Historically, US 25 and M-25, US 27 and M-27, US 33 and M-33, US 112 and M-112, US 131 and M-131 have also both existed at the same times. US 102 and M-102 have have also briefly existed at the same time in 1928; if not, it was a near miss by a matter of weeks. M-2 may have been used on the Jeffries Freeway service drives in the 1970s, duplicating US 2's number at that time.

In 1926, the state renumbered highways and avoided duplicating US Highway numbers except where highways were renumbered as implied continuations of new US Highways: US 24 and M-24 had a common terminus in Pontiac, and US 131 and M-131 had a common terminus near Fife Lake. Other later changes resulted in M-25 as an extension of US 25 in the Thumb. Later M-10 was used for former sections of US 10, and M-27 was assigned to a former section of US 27. So over the years, any internal rule against duplication was relaxed and then disregarded completely by the time the Interstates were designated.

I always thought it was weird that M16 wasn't reused after US 16 was decommissioned.  I mean....US 16 largely WAS M-16 originally even before the US Route system existed.  You'd think with the M-27s and M-25s out there that the original designation would have come back instead of a crap ton of new ones.

[Quillz]

It's...interesting seeing some states like New Mexico and California that have massive log books like this but never went through and truly cleaned things up.  New Mexico is a complete disaster with random numbers...and California had the LRN renumberings that really fell short in terms of missing an opportunity to make signage more simple in an era we it would have been considered useful.  But...that's where I think that I said some inflaming comments in another thread...before I get too side tracked I'll stop. 

With regards to California: I think the biggest flaws in how the post-1964 numbering has been handled are 1. forcing every route designation to be reviewed legislatively (when pre-1964, the signed designations were handled by the old Division of Highways) and 2. by extension, inconsistent in-the-field signage requirements if cities decide to maintain their own portions of what was a numbered route. 

One side effect of this too is a certain inflexibility in rerouting highways to reflect current traffic patterns.  For instance, the new Route 78/Route 111 bypass of Brawley is a perfect spot to clean up the 86/111 designations from there to the border, yet no changes have been made beyond a planned decommissioning of Route 86 through El Centro.  The existence of Route 14U and the past existence of Route 86S also are unintended consequences of how the California numbering system is used in practice.

I agree. The current California system is a complete mess. Looking at older highway maps, there was actually an order to how numbers were assigned. There were more concurrencies, but nothing extreme, and I'd argue they were better for the sake of maintaining continuity and navigation. Now numbers are just assigned randomly, even numbers travel south-north, odd numbers travel west-east, routes simply "disappear" from community to community, it's a mess. Too bad it will never really be fixed, either.

[Quillz]

Makes me wonder though, why not just have something like I-238 signed as I-180 but legislatively it exists as part of route 238?  Would that technically be a duplication in the eyes of the legislatures?...I would suspect not with all ye unsigned routes throughout the state.

I think the non-duplication thing is more a Caltrans push than a legislative one: no duplicate numbers means that there's no confusion as to what route refers to what, and the reduction of concurrencies in theory was supposed to simplify how much travelers would have to remember for navigation.

Of course, the I-15E/Route 194 and Business 80/Route 51 dual-designation situations subvert this to some degree.

I've always liked the system used elsewhere (particularly Massachusetts) where the numbered routes do not reflect state maintenance, but rather (generally) logical navigational routings.

Yeah, that's the issue. Practice has not reflected theory. Say you don't have a paper map, or a GPS, and you want to navigate a route, such as CA-16. Suddenly, you hit I-5 and it just disappears entirely, only to reappear down in Sacramento, and even then, only if you know to get on US-50. If a CA-16 shield was posted alongside I-5, you wouldn't have that confusion. And I really doubt motorists really had much difficulty navigating concurrencies. Plenty of other routes do things like that, too. Wouldn't be too much of an issue if the local communities maintained shields like they are (supposed?) to.

[TheHighwayMan3561]

Minnesota has four duplications. 61, 65, and 169 are extensions (or in 61's case a replacement) of US routes. MN 62 is duplicated differently. The original MN 62 is in southwest Minnesota. When the Hennepin County 62 freeway was turned over to the state in 1988, it became MN 62. The original, a rural route, was not renumbered.

MN 35 and MN 94 were renumbered to MN 135 and MN 194 when I-35 and I-94 were commissioned.

[thenetwork]

Colorado is debatable -- especially when it comes down to CO-470 and E-470.  CO-470 is maintained by CDOT, while E-470 is a privately run Toll Road.  They also use different shields even though 470 is a continuous road skirting Denver on 3 sides.

Is the entire route referred to simply as "the 470" or "Highway 470"? Or do locals differentiate between the two? Just a question, not necessarily related to the topic at hand.

No, it's either C-470 OR E-470.

[bulldog1979]

I always thought it was weird that M16 wasn't reused after US 16 was decommissioned.  I mean....US 16 largely WAS M-16 originally even before the US Route system existed.  You'd think with the M-27s and M-25s out there that the original designation would have come back instead of a crap ton of new ones.

It makes a bit of sense though. At the time it was removed, most of US 16 was essentially I-196 or I-96. The western end in Muskegon became BS I-196 for a year and then BS I-96. The eastern end in the Detroit area was similarly BS I-96, leaving just the middle segment in Lansing needing a new number. They could have resurrected M-16 there in a greatly reduced form, but the northwestern part of old US 16 in Lansing became part of BL I-96, and it like appeared easier to just extend M-43 over the rest rather than add another number to the system overall.

[Bickendan]

Does Oregon have a rule? Other than OR-82 and OR-84, which are relatively short routes and not near either I-82 or I-84, seems the state does not do duplication. There used to be a OR-26, but it was later replaced by US-20 and likely due to the US-26 also having been created.

There is no OR 84.
OR 26 was removed in 1945.
The only two duplicated routes in Oregon are 82 and 205; OR 82 could be argued it's an extension by way of unsigned overlap on I-84 from I-82 (it's not), and OR 205 has absolutely no relation to I-205. Neither cause any confusion.

Let's make a list for all states. (This is mostly from the other replies on this thread, so there may be some inaccuracies.)

OR: I-84 and OR 84.

No 84 duplication in Oregon.

[Max Rockatansky]

I always thought it was weird that M16 wasn't reused after US 16 was decommissioned.  I mean....US 16 largely WAS M-16 originally even before the US Route system existed.  You'd think with the M-27s and M-25s out there that the original designation would have come back instead of a crap ton of new ones.

It makes a bit of sense though. At the time it was removed, most of US 16 was essentially I-196 or I-96. The western end in Muskegon became BS I-196 for a year and then BS I-96. The eastern end in the Detroit area was similarly BS I-96, leaving just the middle segment in Lansing needing a new number. They could have resurrected M-16 there in a greatly reduced form, but the northwestern part of old US 16 in Lansing became part of BL I-96, and it like appeared easier to just extend M-43 over the rest rather than add another number to the system overall.

I think the BL Routes had a lot more equity back in those days given the Interstates were a new shinny thing in the 1960s.  I would be fine with it so long as you could travel between Lansing and Detroit via Grand River on signed trunk lines.  It was always kind of fun to get off I-96 and just explore the older road when I was in high school, it was really the first time I had an opportunity to explore something like that...92 Sunbird and all. 

[TEG24601]

*Non-BBC2 Word*

Err, odd cultural reference...

BBC2 is much more sweary than BBC1. It's also far more likely to have nudity - that more niche and artsy brief vs the populist brief of BBC1.

The third and fourth seasons of (the excellent) The Thick of It aired first on BBC2. (very NSFW - this is perhaps one of less OTT ones)

But the c-word is always post-10pm, unlike news channels (Radio 4, and today SkyNews) where Jeremy Hunt's name seems to get mispronounced more often than not

It is something James May says, and indicates to me something more severe than what BBC 2 would allow.  In this case a word that is even rare on US Premium Cable.

[SteveG1988]

NJ has strict rules.

No Duplication, any US route takes precident over a State Route.

Any Interstate takes precident over a State Route

If a State Route meets an out of state route, it takes that number. NJ73 NJ440 NJ413 are prime examples I think NJ17, and 94 are as well.

[8.Lug]

And about the section of NY 17/I-86 near Sayre, does it even show up in PennDOT route logs at all? I was under the impression that it was a NYSDOT designed, built, and maintained road that incidentally crossed the PA border for a very short distance.

Interesting question because there definitely aren't any "Entering Pennsylvania/New York" signs there, unless my observation skills are just really that bad and I somehow missed them. I'll actually be traveling that route again Sunday morning (07/17/2016) so I'll keep an eye out.

[DandyDan]

As I read into it, Nebraska technically does not have duplicates.  Several highways are discontinuous.  For NE 2, or as the Nebraska log book calls it, N-2, when the western segment ends, it says in the log book, which can be found at http://www.transportation.nebraska.gov/docs/logbook.pdf , "N-2 STOPS. RESUMES APPROXIMATELY 81.77 MILES".  I personally think it looks stupid the way they do it, though.

Iowa has both an IA 136 and a US 136.  There were two IA 15's and both IA 77 and US 77 prior to July 1, 2003. 

[bulldog1979]

I think the BL Routes had a lot more equity back in those days given the Interstates were a new shinny thing in the 1960s.  I would be fine with it so long as you could travel between Lansing and Detroit via Grand River on signed trunk lines.  It was always kind of fun to get off I-96 and just explore the older road when I was in high school, it was really the first time I had an opportunity to explore something like that...92 Sunbird and all. 

Maybe, but Grand River Avenue between Grand Rapids and the Lansing area hasn't been a trunkline since I-96 was built to the south of it, and the same goes for the section between Webberville and Farmington, other than the business loop at Howell. Once the new freeway was built, the old road was turned back to the local jurisdictions. The core purpose of the road had been usurped, and there wasn't any reason for the state to retain it in most places.

[Max Rockatansky]

I think the BL Routes had a lot more equity back in those days given the Interstates were a new shinny thing in the 1960s.  I would be fine with it so long as you could travel between Lansing and Detroit via Grand River on signed trunk lines.  It was always kind of fun to get off I-96 and just explore the older road when I was in high school, it was really the first time I had an opportunity to explore something like that...92 Sunbird and all. 

Maybe, but Grand River Avenue between Grand Rapids and the Lansing area hasn't been a trunkline since I-96 was built to the south of it, and the same goes for the section between Webberville and Farmington, other than the business loop at Howell. Once the new freeway was built, the old road was turned back to the local jurisdictions. The core purpose of the road had been usurped, and there wasn't any reason for the state to retain it in most places.

True...guess it goes back to the old signage for navigation argument rather than who maintains it.  I suppose it really doesn't matter really because if there was a problem on I-96 most of the locals knew Grand River was there to get around it.

[english si]

It is something James May says, and indicates to me something more severe than what BBC 2 would allow.  In this case a word that is even rare on US Premium Cable.

OK, it was on a 'Red Button' bonus feature after a special episode on BBC4, but this kind of thing is what got The Thick of It mainstream enough to move from the artsy BBC4 to the cult-TV BBC2 for Seasons 3 and 4 (has more c-words than the last season of GoT crammed into a few seconds - very much not safe for work).

Capaldi became a massive star in the UK via swearing on BBC2 (and BBC4 before that) - including the c-word (he did an ad for a cancer charity saying he was going to talk about "the 'c-word' and not his usual one").

The issue is timeslot (TG starting at 8pm, not 10pm, and thus TV needing to be something equivalent to TV-14 in the US), and James May is wrong about any word being a 'non-BBC2' word. BBC2 is probably more willing than HBO et al to use that particular word.

[odditude]

NJ: no duplication across Interstate, US, state, and primary county (500-series) routes. secondary county routes can be duplicated in other counties.