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National Boards => General Highway Talk => Topic started by: hotdogPi on April 16, 2018, 09:39:36 AM

Title: Which states allow number duplication?
Post by: hotdogPi on April 16, 2018, 09:39:36 AM
There are a lot of mentions of states allowing or not allowing number duplication, but there doesn't seem to be a reference list all in one place.

I'll start:

Maine: I-195 and ME 195 is the only example with nonsuffixed routes. There are some suffixed examples like US 1A and ME 4A.
New Hampshire: US 4 and NH 4, as well as some suffixed routes.
Massachusetts: I-295 and MA 295 is the only example; US 3 and MA 3 is arguable (it's a single corridor). Suffixed routes are assumed to have a hidden overlap; they are not separate routes.
Rhode Island: No duplication.
Connecticut: No duplication.
Vermont: No duplication.
New York: Interstates and state routes can be duplicated. US routes and state routes cannot, except for 2, 15, and former 220, for all of which the US route is very short in New York.
California: No duplication, but an Interstate and a state route can have the same number if they are part of the same corridor.
Arkansas: Duplication allowed with no restrictions. Two state routes can have the same number; this is a common occurrence.
Georgia: State routes can duplicate both Interstates and US routes.
Title: Re: Which states allow number duplication?
Post by: jeffandnicole on April 16, 2018, 09:47:58 AM
NJ has I-676 and CR 676, but no Interstate/US/State dups.
Title: Re: Which states allow number duplication?
Post by: WillWeaverRVA on April 16, 2018, 09:49:35 AM
Virginia does not typically allow duplication, although there are two three exceptions:

- VA 13 (http://www.vahighways.com/route-log/va013.htm) came into existence after US 13 was already around...in fact, there was already another VA 13 at the time (it was a state route extension of US 13, which did not yet exist on the mainland).

- VA 360 and US 360. (https://www.flickr.com/photos/willshighways/15415794562/in/album-72157648257859042/) VA 360 is an old alignment of US 360.

- US 33 and VA 33; VA 33 is a state route extension of US 33.

North Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).
Title: Re: Which states allow number duplication?
Post by: SP Cook on April 16, 2018, 09:51:44 AM
West Virginia has only one duplicate number, there is a WV 68 and I-68.  The former US 48 was "promoted" to I-68 and there was no reason to renumber because they are about as far apart as possible.

There is a sign on I-70 in Maryland that reads "this is MD 68 - For I-68 Stay on I-70", which is confusing.   
Title: Re: Which states allow number duplication?
Post by: NWI_Irish96 on April 16, 2018, 10:14:57 AM
Indiana allowed duplication between State routes 64, 65, 69, 70 and their interstate counterparts.  I-64 and IN 64 actually intersect each other.  Indiana does not allow duplication between State routes and US routes.  The most notable example is when US 35 was commissioned in Indiana, the existing IN 35 was changed to IN 135.  The only exception was US 131 and IN 131, which were both very short and at opposite ends of the state, so no real confusion was possible.  IN 131 is gone now anyway. 
Title: Re: Which states allow number duplication?
Post by: hockeyjohn on April 16, 2018, 10:15:12 AM
Indiana has Interstate and State Road duplications (64, 65, 69 and 70), but not US Highway and State Road.

Michigan has some US Highway and State Road duplications (8, 10, 24, and 45).
Title: Re: Which states allow number duplication?
Post by: LM117 on April 16, 2018, 11:09:28 AM
Quote from: WillWeaverRVA on April 16, 2018, 09:49:35 AMNorth Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).

Two current NC duplicates that aren't future interstates are NC-73/I-73 and NC-87/I-87. There will also be NC-42/I-42 whenever I-42 shields go up, though NCDOT originally wanted I-36 but that was rejected by AASHTO since it violated the numbering grid and changed it to I-42. NCDOT was forced to eat that one.
Title: Re: Which states allow number duplication?
Post by: hbelkins on April 16, 2018, 11:13:08 AM
Kentucky does not, with two exceptions (three if you count a West Virginia incursion into the Bluegrass State.)

KY 79 and US 79. The two routes do not intersect, and to my knowledge never did intersect, but KY 79 could be construed to be an extension of US 79 northeastward out of Russellville.

KY 69 and I-69. This came about by the addition of I-69 southwest of Indianapolis. The two routes are in the same general area of Kentucky, but do not intersect and there should be no confusion issues.

The West Virginia incursion involves US 52. When the new portion of Corridor G was built between Williamson and the US 52/119 split, it was deemed easier and cheaper to have the route cross into Kentucky twice, rather than follow the Tug Fork of the Big Sandy River on the WV side. The route is owned and maintained by West Virginia, so technically there is no US 52 in Kentucky to conflict with KY 52. If Kentucky ever did take ownership of the route, it would be easy to avoid duplication if necessary by calling it US 119.

Tennessee has all sorts of duplication. State routes can duplicate both interstates and US routes.
Title: Re: Which states allow number duplication?
Post by: WillWeaverRVA on April 16, 2018, 11:19:52 AM
Quote from: LM117 on April 16, 2018, 11:09:28 AM
Quote from: WillWeaverRVA on April 16, 2018, 09:49:35 AMNorth Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).

Two current NC duplicates that aren't future interstates are NC-73/I-73 and NC-87/I-87. There will also be NC-42/I-42 whenever I-42 shields go up, though NCDOT originally wanted I-36 but that was rejected by AASHTO since it violated the numbering grid and changed it to I-42. NCDOT was forced to eat that one.

I forgot about I-42/NC 42...and I don't even want to think about I-87. ;)
Title: Which states allow number duplication?
Post by: adventurernumber1 on April 16, 2018, 11:28:45 AM
Tennessee must be one of the states that allows number duplication, because there is at least both a US 27 and a TN SR 27. Heck, US 27 and TN 27 even both go through the Chattanooga area! See here:

(https://uploads.tapatalk-cdn.com/20180416/8265f410aaf91bf228e460d876537a03.jpg)
Title: Re: Which states allow number duplication?
Post by: Doctor Whom on April 16, 2018, 11:29:32 AM
Quote from: SP Cook on April 16, 2018, 09:51:44 AMThere is a sign on I-70 in Maryland that reads "this is MD 68 - For I-68 Stay on I-70", which is confusing.
Maryland has several Interstate/state duplicates, although except for that example, they are either in the same corridor (like I-295 and Md. 295) or far enough apart that there is little likelihood of confusion (like I-97 and Md. 97).
Title: Re: Which states allow number duplication?
Post by: jemacedo9 on April 16, 2018, 11:32:23 AM
PA has:
PA 99 and I-99: PA 99 is internally numbered as SR 0399
PA 86 and I-86: PA 86 is internally numbered as SR 0886
PA 380 and I-380: PA 380 is internally numbered as SR 0400
PA 283 and I-283: PA 283 is somewhat of an extension of sorts of I-283 and is internally numbered as SR 0300

There are two separate PA 97s.  The southern PA 97 was once US 140, but when that was decommissioned it was numbered to match MD 97.  Both are internally numbered as SR 0097
There are two separate PA 29s.  I believe they used to connect along PA 309. Both are internally numbered as SR 0029
There are also the separate US 422s with an implied connection via US 22 and US 322.

Soon, there will be a PA 295 and an I-295.

Title: Re: Which states allow number duplication?
Post by: ftballfan on April 16, 2018, 12:02:19 PM
Quote from: hockeyjohn on April 16, 2018, 10:15:12 AM
Michigan has some US Highway and State Road duplications (8, 10, 24, and 45).
All their 2di's are also used for state highways (69, 75, 94, 96). However, M-16 has yet to be reused despite US-16 being decommissioned in the state over 50 years ago
Title: Re: Which states allow number duplication?
Post by: Flint1979 on April 16, 2018, 12:17:21 PM
Michigan has
US-8 and M-8
US-10 and M-10
US-24 and M-24
US-45 and M-45
I-69 and M-69
I-75 and M-75
I-94 and M-94
I-96 and M-96
Title: Re: Which states allow number duplication?
Post by: wxfree on April 16, 2018, 01:09:34 PM
Texas allows duplication of numbers.  A list of examples would be extensive.  Here's a list of road types across which a number could be duplicated.  Types separated by commas may use duplicates, while types separated by slashes share a pool of numbers.  Alternate and business routes are not listed.

Interstates, US highways, state highways, loops/spurs, farm/ranch to market/urban roads, park roads, recreation roads, and ranch roads.  There's only one Ranch Road (1), but the system has its own number pool and uses a duplicate of a farm to market road number.  There's also the principle arterial state system which provides state aid for certain city streets that are not designated state highways but are described as being part of the state highway system.

The most used number may be 10, which is used for an Interstate, a state highway, a farm to market road, a spur, a park road, and a recreation road (6 of the 8 categories, excluding PASS roads).
Title: Re: Which states allow number duplication?
Post by: Mapmikey on April 16, 2018, 01:18:16 PM
Quote from: WillWeaverRVA on April 16, 2018, 09:49:35 AM
Virginia does not typically allow duplication, although there are two three exceptions:

- VA 13 (http://www.vahighways.com/route-log/va013.htm) came into existence after US 13 was already around...in fact, there was already another VA 13 at the time (it was a state route extension of US 13, which did not yet exist on the mainland).

- VA 360 and US 360. (https://www.flickr.com/photos/willshighways/15415794562/in/album-72157648257859042/) VA 360 is an old alignment of US 360.

- US 33 and VA 33; VA 33 is a state route extension of US 33.

North Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).

Make it six:  I-381/VA 381; US 211/VA 211; US 311 and VA 311.  The CTB in theory was going to discuss renumbering VA 311 when US 311 came back but the issue just kinda went away.

Virginia has had several more US-VA duplications of one turning into the other (or very close):

US 17-VA 17
US 29-VA 29 (was just like the US 360/VA 360 setup of today)
US 121-VA 121
US 158-VA 158
US 258-VA 258
US 301-VA 301
US 311-VA 311
US 340-VA 340
US 501-VA 501

South Carolina allows duplication of interstate and state route numbers...
Title: Re: Which states allow number duplication?
Post by: odditude on April 16, 2018, 01:42:53 PM
Delaware:
Quote from: jeffandnicole on April 16, 2018, 09:47:58 AM
NJ has I-676 and CR 676, but no Interstate/US/State dups.

NJ has many duplicates among 600-series county routes, which only prohibit duplication within county limits. While in some cases, there are numbers continued across county lines, this is more the exception than the rule.

There are no duplicates in the 500-series county routes.
Title: Re: Which states allow number duplication?
Post by: pianocello on April 16, 2018, 01:50:27 PM
AFAIK, Iowa doesn't prohibit it, but there's only case where duplication exists: IA 136 and US 136. It helps that US 136 just clips the southern tip.

Illinois allows it; it even provides the first (?) example of an Interstate and US highway sharing a number within the same state (24). There were a few state routes that changed numbers due to intersecting new Interstate highways with the same number, most notably IL 80 (now 84) and IL 88 (now 40).
Title: Re: Which states allow number duplication?
Post by: TheHighwayMan3561 on April 16, 2018, 02:19:11 PM
Minnesota does in limited cases:
-Two MN 62s - the original MN 62 is a rural two-lane road. The more well-known MN 62 in the Twin Cities came to be in 1988 when MnDOT took control of Hennepin County's Crosstown Expressway, County Road 62.
-US 61 and MN 61 (MN 61 replaced part of a decommissioned section of US 61)
-US 169 and MN 169 (MN 169 is a state "extension" of MN 169, separated by a few miles of US 53)
-US 65 and MN 65 (same as 169, though in this case the two directly intersected in downtown Minneapolis before US 65 was eliminated north of Albert Lea)
Title: Re: Which states allow number duplication?
Post by: cl94 on April 16, 2018, 02:33:04 PM
14 Interstates and 2 US routes in New York are duplicated. An exhaustive list of existing cases:

- US/NY 2
- US/NY 15 (NY 15 was once entirely US 15)
- I-/NY 81
- I-/NY 86
- I-/NY 88
- I-/NY 90 (these actually cross)
- I-/NY 190
- I-/NY 290
- I-/NY 295
- I-/NY 787 (while related, NY 787 is NOT an extension of I-87)

There are also a handful of cases where a state route is a non-Interstate extension of an Interstate:

- NY 390
- NY 481
- NY 495
- NY 590
- NY 690
- NY 890

- The only NY route whose number was changed as a result of a new Interstate was NY 84, which is now NY 284.
- NY 87 was a former duplication, but it was renumbered when NY 812 was extended to provide a continuous route from NY 12 to the Canadian border in Ogdensburg.
- NY 220 duplicated US 220 until US 220 was truncated to I-86/NY 17 in Pennsylvania
- NY 99 was decommissioned 20 years before I-99 entered New York.
Title: Re: Which states allow number duplication?
Post by: MNHighwayMan on April 16, 2018, 03:57:52 PM
Quote from: TheHighwayMan394 on April 16, 2018, 02:19:11 PM
Minnesota does in limited cases:
-Two MN 62s - the original MN 62 is a rural two-lane road. The more well-known MN 62 in the Twin Cities came to be in 1988 when MnDOT took control of Hennepin County's Crosstown Expressway, County Road 62.
-US 61 and MN 61 (MN 61 replaced part of a decommissioned section of US 61)
-US 169 and MN 169 (MN 169 is a state "extension" of MN 169, separated by a few miles of US 53)
-US 65 and MN 65 (same as 169, though in this case the two directly intersected in downtown Minneapolis before US 65 was eliminated north of Albert Lea)

And in the same vein as the last two, there are also the former instances of MN-212 and 218. The former later became an extension of MN-5 and 36 and the latter largely became part of MN-25.
Title: Re: Which states allow number duplication?
Post by: hbelkins on April 16, 2018, 04:17:10 PM
Quote from: Mapmikey on April 16, 2018, 01:18:16 PM
US 121-VA 121

The current VA 121 doesn't have anything to do with a former routing of any US 121, does it? The current VA 121 ends at Max Meadows and could probably work just as easily as a 6xx series secondary route.

Of course if the Coalfields Expressway is ever built, there will be a duplication since it's going to be numbered US 121.
Title: Re: Which states allow number duplication?
Post by: TheHighwayMan3561 on April 16, 2018, 04:34:58 PM
Quote from: MNHighwayMan on April 16, 2018, 03:57:52 PM
Quote from: TheHighwayMan394 on April 16, 2018, 02:19:11 PM
Minnesota does in limited cases:
-Two MN 62s - the original MN 62 is a rural two-lane road. The more well-known MN 62 in the Twin Cities came to be in 1988 when MnDOT took control of Hennepin County's Crosstown Expressway, County Road 62.
-US 61 and MN 61 (MN 61 replaced part of a decommissioned section of US 61)
-US 169 and MN 169 (MN 169 is a state "extension" of MN 169, separated by a few miles of US 53)
-US 65 and MN 65 (same as 169, though in this case the two directly intersected in downtown Minneapolis before US 65 was eliminated north of Albert Lea)

And in the same vein as the last two, there are also the former instances of MN-212 and 218. The former later became an extension of MN-5 and 36 and the latter largely became part of MN-25.

On the other side of the coin, MN 35, MN 90, and MN 94 were all renumbered (each had their numbers increased by 100; MN 190 has been decommissioned while the other two live on). So I guess to follow the OP's criteria, maybe US/state duplicates are allowed but state/interstate ones are not.
Title: Re: Which states allow number duplication?
Post by: Max Rockatansky on April 16, 2018, 04:37:04 PM
Arizona has a bunch with the likes of; US 89, US 89A, AZ 89, AZ 89A, US 95, and AZ 95. 
Title: Re: Which states allow number duplication?
Post by: Big John on April 16, 2018, 04:59:38 PM
Wisconsin generally does not allow duplication, but 2 relatively recent exemptions were made:  WI 39 was allowed to remain when I-39 was extended into Wisconsin, and WI 794 was created as an extension of I-794.
Title: Re: Which states allow number duplication?
Post by: MNHighwayMan on April 16, 2018, 05:11:41 PM
Quote from: TheHighwayMan394 on April 16, 2018, 04:34:58 PM
Quote from: MNHighwayMan on April 16, 2018, 03:57:52 PM
Quote from: TheHighwayMan394 on April 16, 2018, 02:19:11 PM
Minnesota does in limited cases:
-Two MN 62s - the original MN 62 is a rural two-lane road. The more well-known MN 62 in the Twin Cities came to be in 1988 when MnDOT took control of Hennepin County's Crosstown Expressway, County Road 62.
-US 61 and MN 61 (MN 61 replaced part of a decommissioned section of US 61)
-US 169 and MN 169 (MN 169 is a state "extension" of MN 169, separated by a few miles of US 53)
-US 65 and MN 65 (same as 169, though in this case the two directly intersected in downtown Minneapolis before US 65 was eliminated north of Albert Lea)
And in the same vein as the last two, there are also the former instances of MN-212 and 218. The former later became an extension of MN-5 and 36 and the latter largely became part of MN-25.
On the other side of the coin, MN 35, MN 90, and MN 94 were all renumbered (each had their numbers increased by 100; MN 190 has been decommissioned while the other two live on). So I guess to follow the OP's criteria, maybe US/state duplicates are allowed but state/interstate ones are not.

I think it's because MnDOT sees the state numbers as extensions of the US Route numbers–IE they're intended to be seen as the same route, just with a different shield. This was decidedly not the case with old MN-35, 90, and 94, so they were renumbered.

Edit: Another example of that is old MN-63, which was renumbered as 73 when US-63 was extended into Minnesota in the mid-1930s.
Title: Re: Which states allow number duplication?
Post by: US 89 on April 16, 2018, 05:47:25 PM
Utah has a hard policy of no duplications, as route numbers are defined legislatively. Before 1977, when legislative descriptions were changed to match signed routes, there were several duplications. That included a SR-15 which intersected I-15 (now SR-9), and a SR-84 which ran parallel to (and even intersected) I-84 in the Ogden area.
Title: Re: Which states allow number duplication?
Post by: GaryV on April 16, 2018, 05:59:27 PM
Quote from: Flint1979 on April 16, 2018, 12:17:21 PM
Michigan has
US-8 and M-8
US-10 and M-10
US-24 and M-24
US-45 and M-45
I-69 and M-69
I-75 and M-75
I-94 and M-94
I-96 and M-96

Michigan originally (in 1926) did not have duplicates, except as noted below.  Thus M-16, M-23 and a few others disappeared and were renumbered.

The exception was where a state route extended from the US route.  US-24/M-24 is the only example of that left (even though they no longer touch at their former terminii in Pontiac).  Others were 25 and 131; there may have been more but I'm going from memory.

M-10 was a replacement for when US-10 was truncated at Bay City.

M-45 was created when M-50 through Grand Rapids was decommissioned after the coming of the freeways.  I guess they thought M-45 and US-45 were far enough apart.

Seems like when the Interstates came in, they didn't care that there were duplicate numbers.  Those brand spankin' new freeways weren't going to be confused with a state highway.

M-8 is a relatively new numbering for a rather old freeway.  It used to not have a number.  And again, it's a long way from US-8 which most people have never driven on in Michigan.
Title: Re: Which states allow number duplication?
Post by: vdeane on April 16, 2018, 06:15:04 PM
Quote from: cl94 on April 16, 2018, 02:33:04 PM
There are also a handful of cases where a state route is a non-Interstate extension of an Interstate:

- NY 390
- NY 481
- NY 495
- NY 590
- NY 690
- NY 890
NY 878?  Though it's an odd case, with I-878 not signed, not acknowledged by NYSDOT (outside of the Functional Class Viewer), and only existing eastbound.

NY 495 is also an interesting case, being former I-495 but not connected to I-495.  Unless you count that piece of the LIE, which is signed as I-495, and it not being an interstate is an odd technicality only partially acknowledged by NYSDOT (in the Functional Class Viewer and touring route book); no idea what led to that, but IMO the whole LIE should be an interstate or, failing that, at least have more logical endpoints for the parts that are and aren't.
Title: Re: Which states allow number duplication?
Post by: Hurricane Rex on April 16, 2018, 07:43:06 PM
Oregon has:
I-82/OR 82
I-205/OR 205

LG-TP260

Title: Re: Which states allow number duplication?
Post by: bulldog1979 on April 16, 2018, 08:03:17 PM
Quote from: Flint1979 on April 16, 2018, 12:17:21 PM
Michigan has
US-8 and M-8
US-10 and M-10
US-24 and M-24
US-45 and M-45
I-69 and M-69
I-75 and M-75
I-94 and M-94
I-96 and M-96

And historically, Michigan had:
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

Additionally, there was a proposal for an M-275 as a continuation of I-275, and the US 102 and M-102 were probably a near miss, just months apart between the former's decommissioning and the latter's commissioning.
Title: Re: Which states allow number duplication?
Post by: Flint1979 on April 17, 2018, 12:34:18 AM
Quote from: GaryV on April 16, 2018, 05:59:27 PM
Quote from: Flint1979 on April 16, 2018, 12:17:21 PM
Michigan has
US-8 and M-8
US-10 and M-10
US-24 and M-24
US-45 and M-45
I-69 and M-69
I-75 and M-75
I-94 and M-94
I-96 and M-96

Michigan originally (in 1926) did not have duplicates, except as noted below.  Thus M-16, M-23 and a few others disappeared and were renumbered.

The exception was where a state route extended from the US route.  US-24/M-24 is the only example of that left (even though they no longer touch at their former terminii in Pontiac).  Others were 25 and 131; there may have been more but I'm going from memory.

M-10 was a replacement for when US-10 was truncated at Bay City.

M-45 was created when M-50 through Grand Rapids was decommissioned after the coming of the freeways.  I guess they thought M-45 and US-45 were far enough apart.

Seems like when the Interstates came in, they didn't care that there were duplicate numbers.  Those brand spankin' new freeways weren't going to be confused with a state highway.

M-8 is a relatively new numbering for a rather old freeway.  It used to not have a number.  And again, it's a long way from US-8 which most people have never driven on in Michigan.
I've been told and I read up on it that US-24 and M-24 never met up as the same highway. I figured that with M-24's southern terminus and US-24's northern terminus being about 12 miles apart that they were at one time joined because I know that US-24 use to end at Square Lake and US-10 was the routing north of that point. M-25 and US-25 indeed did meet up in Port Austin.

I wouldn't suspect any confusion between M-45 and US-45 considering they are plenty far enough apart. I would think that M-24 and US-24 get confused by people not familiar with Oakland County roads.

M-75 isn't really that far from I-75 but it would take a lot to get those two highways confused.

M-8 came about when the Davison was transferred to the jurisdiction of MDOT in the 90's and then was rebuilt around 1996. Even though some think the Davison is useless as a freeway it still carries about 50,000 vehicles a day. I have actually driven on US-8, I took that way to the Twin Cities one time about 15 years ago you basically turn onto it in Norway and then you're in Wisconsin within a few minutes. I honestly don't understand why it doesn't just end at US-141 in Wisconsin, it already has it's two state limit since it's under 300 miles. It's not in Minnesota for very long either about 22 miles but is in Wisconsin for about 255 miles.
Title: Re: Which states allow number duplication?
Post by: ilpt4u on April 17, 2018, 01:08:47 AM
Quote from: pianocello on April 16, 2018, 01:50:27 PM
Illinois allows it; it even provides the first (?) example of an Interstate and US highway sharing a number within the same state (24). There were a few state routes that changed numbers due to intersecting new Interstate highways with the same number, most notably IL 80 (now 84) and IL 88 (now 40).
Other Land of Lincoln examples: AFAIK none intersect (not counting the I/IL 255 Freeway) Generally, most are in opposite areas of the state. US 6 and IL 6 are not that far away - Distance from Peoria to I-80

I & IL 64
I & IL 70
I & IL 72
I & IL 155
US & IL 50
US & IL 34
US & IL 14
US & IL 40
US & IL 6
US & IL 54 (IL 54 being a segment of decommissioned US 54)
US & IL 150
Title: Re: Which states allow number duplication?
Post by: kurumi on April 17, 2018, 01:18:09 AM
Connecticut did allow duplicate routes long ago, but only for "A" suffixed state and US routes. For example, multiple CT 10A's existed, and multiple US 1A's. They did not secretly overlap connecting routes; they were distinct.
Title: Re: Which states allow number duplication?
Post by: Scott5114 on April 17, 2018, 03:26:56 AM
Quote from: 1 on April 16, 2018, 09:39:36 AM
Arkansas: Duplication allowed with no restrictions. Two state routes can have the same number; this is a common occurrence.

Same applies for Oklahoma, although duplicate state routes are not as commonplace as in Arkansas. Most duplicate routes were either once joined but the middle section decommissioned (often because of the introduction of a higher-level route in the corridor, but sometimes simply because a highway was not needed there) or are two entirely unrelated routes, with one numbered to match a highway in an adjoining state.
Title: Re: Which states allow number duplication?
Post by: formulanone on April 17, 2018, 06:18:40 AM
Florida permits route duplication. Most of its Interstates and US Routes have a similarly-numbered state route, though usually well-distanced from each other. On a few occasions, they renumbered the nearby state route; FL 27 intersected US 27, so the former was split up to FL 997 and FL 9336, since they were completed at different times. A1A was proposed as SR 1 for the 1940s Renumbering, but with US 1 alongside of it, the theory is that it was renamed/renumbered to prevent confusion.

There's some exceptions: US 17 and SR 17, which intersect at one point. SR 10, which is mostly a secret number for US 90, intersects I-10 several times, but only has one segment in Jacksonville where it is listed solely as SR 10 (mostly east of I-10's terminus). US 23 and SR 23 are in the same county, though FL 23 is fairly new...not sure why they didn't use another number for the much-newer route.

FDOT suggests that County Roads should not duplicate nearby numbers, but I'm not sure if they've ever intervened in renumbering one, other than to "upgrade" it to state road status.
Title: Re: Which states allow number duplication?
Post by: Max Rockatansky on April 17, 2018, 08:09:05 AM
Quote from: formulanone on April 17, 2018, 06:18:40 AM
Florida permits route duplication. Most of its Interstates and US Routes have a similarly-numbered state route, though usually well-distanced from each other. On a few occasions, they renumbered the nearby state route; FL 27 intersected US 27, so the former was split up to FL 997 and FL 9336, since they were completed at different times. A1A was proposed as SR 1 for the 1940s Renumbering, but with US 1 alongside of it, the theory is that it was renamed/renumbered to prevent confusion.

There's some exceptions: US 17 and SR 17, which intersect at one point. SR 10, which is mostly a secret number for US 90, intersects I-10 several times, but only has one segment in Jacksonville where it is listed solely as SR 10 (mostly east of I-10's terminus). US 23 and SR 23 are in the same county, though FL 23 is fairly new...not sure why they didn't use another number for the much-newer route.

FDOT suggests that County Roads should not duplicate nearby numbers, but I'm not sure if they've ever intervened in renumbering one, other than to "upgrade" it to state road status.

It seems that FDOT doesn't really intervene.  There are several examples of State and County Route duplicating like FL 589 being a couple miles east of Hernando County Route 589.
Title: Re: Which states allow number duplication?
Post by: ftballfan on April 17, 2018, 09:13:06 AM
Quote from: Max Rockatansky on April 17, 2018, 08:09:05 AM
Quote from: formulanone on April 17, 2018, 06:18:40 AM
Florida permits route duplication. Most of its Interstates and US Routes have a similarly-numbered state route, though usually well-distanced from each other. On a few occasions, they renumbered the nearby state route; FL 27 intersected US 27, so the former was split up to FL 997 and FL 9336, since they were completed at different times. A1A was proposed as SR 1 for the 1940s Renumbering, but with US 1 alongside of it, the theory is that it was renamed/renumbered to prevent confusion.

There's some exceptions: US 17 and SR 17, which intersect at one point. SR 10, which is mostly a secret number for US 90, intersects I-10 several times, but only has one segment in Jacksonville where it is listed solely as SR 10 (mostly east of I-10's terminus). US 23 and SR 23 are in the same county, though FL 23 is fairly new...not sure why they didn't use another number for the much-newer route.

FDOT suggests that County Roads should not duplicate nearby numbers, but I'm not sure if they've ever intervened in renumbering one, other than to "upgrade" it to state road status.

It seems that FDOT doesn't really intervene.  There are several examples of State and County Route duplicating like FL 589 being a couple miles east of Hernando County Route 589.
Then you have the 435's in Orlando
Title: Re: Which states allow number duplication?
Post by: WillWeaverRVA on April 17, 2018, 09:44:48 AM
Quote from: Mapmikey on April 16, 2018, 01:18:16 PM
Quote from: WillWeaverRVA on April 16, 2018, 09:49:35 AM
Virginia does not typically allow duplication, although there are two three exceptions:

- VA 13 (http://www.vahighways.com/route-log/va013.htm) came into existence after US 13 was already around...in fact, there was already another VA 13 at the time (it was a state route extension of US 13, which did not yet exist on the mainland).

- VA 360 and US 360. (https://www.flickr.com/photos/willshighways/15415794562/in/album-72157648257859042/) VA 360 is an old alignment of US 360.

- US 33 and VA 33; VA 33 is a state route extension of US 33.

North Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).

Make it six:  I-381/VA 381; US 211/VA 211; US 311 and VA 311.  The CTB in theory was going to discuss renumbering VA 311 when US 311 came back but the issue just kinda went away.

Argh, I should've known better since I've been by all of those recently.
Title: Re: Which states allow number duplication?
Post by: hbelkins on April 17, 2018, 11:19:31 AM
One reason that route number duplication can be a bad thing...

Saw a Facebook post yesterday from Tennessee DOT about a road closure on "Route 70N." I automatically assumed it was for US 70N. After I read the suggested detour routes, I realized that it was not for US 70N, but for TN 70 north of Rogersville.
Title: Re: Which states allow number duplication?
Post by: MNHighwayMan on April 17, 2018, 11:23:08 AM
Quote from: hbelkins on April 17, 2018, 11:19:31 AM
One reason that route number duplication can be a bad thing...

Saw a Facebook post yesterday from Tennessee DOT about a road closure on "Route 70N." I automatically assumed it was for US 70N. After I read the suggested detour routes, I realized that it was not for US 70N, but for TN 70 north of Rogersville.

That's not a problem with number duplication—that's a problem of using ambiguous terminology. "Route 70N" can mean either a route labeled "70N," or it can mean "Route 70, N" as in NB Route 70.
Title: Re: Which states allow number duplication?
Post by: Rothman on April 17, 2018, 12:01:51 PM
Quote from: MNHighwayMan on April 17, 2018, 11:23:08 AM
Quote from: hbelkins on April 17, 2018, 11:19:31 AM
One reason that route number duplication can be a bad thing...

Saw a Facebook post yesterday from Tennessee DOT about a road closure on "Route 70N." I automatically assumed it was for US 70N. After I read the suggested detour routes, I realized that it was not for US 70N, but for TN 70 north of Rogersville.

That's not a problem with number duplication–that's a problem of using ambiguous terminology. "Route 70N" can mean either a route labeled "70N," or it can mean "Route 70, N" as in NB Route 70.
Wouldn't have to worry about ambiguity if duplication was avoided.
Title: Re: Which states allow number duplication?
Post by: roadfro on April 21, 2018, 01:57:44 PM
Nevada does not allow duplication of route numbers on the state highway system.

(There used to be duplication of internal numbers for roads in the "frontage road" network, where same numbers were used for different roads in different counties. These have since been changed to include the county abbreviations as part of the number. These numbers aren't signed at all, except on field mileposts.)
Title: Re: Which states allow number duplication?
Post by: Flint1979 on April 21, 2018, 06:07:35 PM
I sometimes wish Michigan wouldn't duplicate routes. M-75 is in the same part of the state that a stretch of I-75 runs through, M-75 is west of I-75 by less than 20 miles. M-75 is basically just a spur route off of US-131 pretty much serving just Boyne City so unless you are going to Boyne City M-75 is pretty much a useless highway anyway.

M-94 is in the Upper Peninsula a long ways from I-94.
M-96 isn't too far from I-96 as it runs between Kalamazoo and Marshall.
M-69 is in the Upper Peninsula like M-94 it's a long ways from I-69.
Title: Re: Which states allow number duplication?
Post by: jp the roadgeek on April 22, 2018, 12:13:18 AM
Quote from: 1 on April 16, 2018, 09:39:36 AM
Rhode Island: No duplication.

Actually, there is.  There's RI 1A in South County that has 5 separate pieces between Westerly and North Kingstown with silent concurrencies with US 1 in between, and there's US 1A through Warwick, Cranston, Providence, and Pawtucket (which becomes MA 1A at the border).
Title: Re: Which states allow number duplication?
Post by: Road Hog on April 22, 2018, 02:22:56 AM
Quote from: Scott5114 on April 17, 2018, 03:26:56 AM
Quote from: 1 on April 16, 2018, 09:39:36 AM
Arkansas: Duplication allowed with no restrictions. Two state routes can have the same number; this is a common occurrence.

Same applies for Oklahoma, although duplicate state routes are not as commonplace as in Arkansas. Most duplicate routes were either once joined but the middle section decommissioned (often because of the introduction of a higher-level route in the corridor, but sometimes simply because a highway was not needed there) or are two entirely unrelated routes, with one numbered to match a highway in an adjoining state.
Arkansas does, of course, have numerous disjointed highways with the same number.

But I think the intent of the OP was duplication of numbers across designations (state/US/interstate). Arkansas until recently did have a restriction on duplication (with exceptions for future interstates, i.e. AR 440/I-440), but finally relaxed it when I-49 came on the scene because of US 49 on the other side of the state.
Title: Re: Which states allow number duplication?
Post by: TEG24601 on April 22, 2018, 02:09:16 PM
Quote from: Flint1979 on April 17, 2018, 12:34:18 AM
Quote from: GaryV on April 16, 2018, 05:59:27 PM
Quote from: Flint1979 on April 16, 2018, 12:17:21 PM
Michigan has
US-8 and M-8
US-10 and M-10
US-24 and M-24
US-45 and M-45
I-69 and M-69
I-75 and M-75
I-94 and M-94
I-96 and M-96

Michigan originally (in 1926) did not have duplicates, except as noted below.  Thus M-16, M-23 and a few others disappeared and were renumbered.

The exception was where a state route extended from the US route.  US-24/M-24 is the only example of that left (even though they no longer touch at their former terminii in Pontiac).  Others were 25 and 131; there may have been more but I'm going from memory.

M-10 was a replacement for when US-10 was truncated at Bay City.

M-45 was created when M-50 through Grand Rapids was decommissioned after the coming of the freeways.  I guess they thought M-45 and US-45 were far enough apart.

Seems like when the Interstates came in, they didn't care that there were duplicate numbers.  Those brand spankin' new freeways weren't going to be confused with a state highway.

M-8 is a relatively new numbering for a rather old freeway.  It used to not have a number.  And again, it's a long way from US-8 which most people have never driven on in Michigan.
I've been told and I read up on it that US-24 and M-24 never met up as the same highway. I figured that with M-24's southern terminus and US-24's northern terminus being about 12 miles apart that they were at one time joined because I know that US-24 use to end at Square Lake and US-10 was the routing north of that point. M-25 and US-25 indeed did meet up in Port Austin.

I wouldn't suspect any confusion between M-45 and US-45 considering they are plenty far enough apart. I would think that M-24 and US-24 get confused by people not familiar with Oakland County roads.

M-75 isn't really that far from I-75 but it would take a lot to get those two highways confused.

M-8 came about when the Davison was transferred to the jurisdiction of MDOT in the 90's and then was rebuilt around 1996. Even though some think the Davison is useless as a freeway it still carries about 50,000 vehicles a day. I have actually driven on US-8, I took that way to the Twin Cities one time about 15 years ago you basically turn onto it in Norway and then you're in Wisconsin within a few minutes. I honestly don't understand why it doesn't just end at US-141 in Wisconsin, it already has it's two state limit since it's under 300 miles. It's not in Minnesota for very long either about 22 miles but is in Wisconsin for about 255 miles.
I don't see route duplication being and issue in Michigan, since all state routes are M-X, and are spoken as such.  It isn't common to confuse them with the other route numbers.  In other states, like Washington, duplication could be confusing, because some people just use the route number, say "the" then route number, say "highway" then the route number, and others state the route type and number.
Title: Re: Which states allow number duplication?
Post by: cjk374 on April 22, 2018, 04:02:24 PM
Louisiana has duplicate route numbers:

I-59 & LA 59: they are only 20 miles apart. At the LA 59 exit, there are trail blazers pointing straight ahead on I-12.

I-10 & LA 10

I-12 & LA 12

I-20 & LA 20

I-55 & LA 55

I-49 & LA 49 (a 200+ mile interstate vs a 3.93 mile state highway.)

I-510 & LA 510

I-910 & LA 910
Title: Re: Which states allow number duplication?
Post by: Flint1979 on April 22, 2018, 05:16:25 PM
Quote from: TEG24601 on April 22, 2018, 02:09:16 PM
Quote from: Flint1979 on April 17, 2018, 12:34:18 AM
Quote from: GaryV on April 16, 2018, 05:59:27 PM
Quote from: Flint1979 on April 16, 2018, 12:17:21 PM
Michigan has
US-8 and M-8
US-10 and M-10
US-24 and M-24
US-45 and M-45
I-69 and M-69
I-75 and M-75
I-94 and M-94
I-96 and M-96

Michigan originally (in 1926) did not have duplicates, except as noted below.  Thus M-16, M-23 and a few others disappeared and were renumbered.

The exception was where a state route extended from the US route.  US-24/M-24 is the only example of that left (even though they no longer touch at their former terminii in Pontiac).  Others were 25 and 131; there may have been more but I'm going from memory.

M-10 was a replacement for when US-10 was truncated at Bay City.

M-45 was created when M-50 through Grand Rapids was decommissioned after the coming of the freeways.  I guess they thought M-45 and US-45 were far enough apart.

Seems like when the Interstates came in, they didn't care that there were duplicate numbers.  Those brand spankin' new freeways weren't going to be confused with a state highway.

M-8 is a relatively new numbering for a rather old freeway.  It used to not have a number.  And again, it's a long way from US-8 which most people have never driven on in Michigan.
I've been told and I read up on it that US-24 and M-24 never met up as the same highway. I figured that with M-24's southern terminus and US-24's northern terminus being about 12 miles apart that they were at one time joined because I know that US-24 use to end at Square Lake and US-10 was the routing north of that point. M-25 and US-25 indeed did meet up in Port Austin.

I wouldn't suspect any confusion between M-45 and US-45 considering they are plenty far enough apart. I would think that M-24 and US-24 get confused by people not familiar with Oakland County roads.

M-75 isn't really that far from I-75 but it would take a lot to get those two highways confused.

M-8 came about when the Davison was transferred to the jurisdiction of MDOT in the 90's and then was rebuilt around 1996. Even though some think the Davison is useless as a freeway it still carries about 50,000 vehicles a day. I have actually driven on US-8, I took that way to the Twin Cities one time about 15 years ago you basically turn onto it in Norway and then you're in Wisconsin within a few minutes. I honestly don't understand why it doesn't just end at US-141 in Wisconsin, it already has it's two state limit since it's under 300 miles. It's not in Minnesota for very long either about 22 miles but is in Wisconsin for about 255 miles.
I don't see route duplication being and issue in Michigan, since all state routes are M-X, and are spoken as such.  It isn't common to confuse them with the other route numbers.  In other states, like Washington, duplication could be confusing, because some people just use the route number, say "the" then route number, say "highway" then the route number, and others state the route type and number.
You don't have everyone saying the "M" and I'm one that doesn't always use it either. Like for M-47 I'll just call it 47 or Midland Road, same for 46 or Gratiot or Holland/Remington, but M-58 really never gets called by it's route number it's known by State Street and also Davenport Avenue in the one way stretch. It might just be a Saginaw County thing because M-46 is known as M-46 more popularly than it's road name in other parts of the state. And it's funny because for Bay Road I'll call it M-84 in Bay County but call it Bay Road in Saginaw County. In Bay County it's name is Westside Saginaw Road, then Salzburg, then Lafayette, then Garfield, then Washington. While M-84 is on the Salzburg/Lafayette stretch it has a wrong way multiplex with M-13.
Title: Re: Which states allow number duplication?
Post by: US71 on April 22, 2018, 06:00:45 PM
Arkansas has lots of state highway duplication.  AR 45 and AR 74 are two of the biggest offenders, but these were chopped up over the years.

But we also have US 59 and AR 59
US 49 and I-49 (200 mile separation)
AR 440 and I-440 (AR 440 likely to be upgraded sometime in the future)
AR 530 and I-530 (AR 530 a possible future reroute of I-530)


Title: Re: Which states allow number duplication?
Post by: jp the roadgeek on April 22, 2018, 09:26:00 PM

Quote from: cl94 on April 16, 2018, 02:33:04 PM
There are also a handful of cases where a state route is a non-Interstate extension of an Interstate:

- NY 390
- NY 481
- NY 495
- NY 590
- NY 690
- NY 787
- NY 890

FTFY


Title: Re: Which states allow number duplication?
Post by: cl94 on April 22, 2018, 09:37:36 PM
Purposely excluded from my list of extensions because it's not an extension. It's a spur off of I-787. I-787 crosses the Collar City Bridge and ends in Troy.
Title: Re: Which states allow number duplication?
Post by: Bickendan on April 22, 2018, 11:45:13 PM
Quote from: Hurricane Rex on April 16, 2018, 07:43:06 PM
Oregon has:
I-82/OR 82
I-205/OR 205
While Oregon doesn't allow for duplication outside these two pairs for the routes, the highways have quite a few duplications with the routes.
3 Oswego Hwy and 3 Enterprise-Lewiston Hwy
5 John Day Hwy and 5 Pacific Hwy
6 Old Oregon Trail and 6 Wilson River Hwy
7 Central Oregon Hwy and 7 Baker-Copperfield Hwy/Whitney Hwy
8 Oregon-Washington Hwy and 8 Gales Creek Rd/TV Hwy
10 Wallowa Lake Hwy and 10 Farmington Rd/Beaverton-Hillsdale Hwy
11 Enterprise-Lewiston Hwy and 11 Oregon-Washington Hey
18 Willamette Hwy and 18 Salmon River Hwy
19 Fremont Hwy and 19 John Day Hwy
20 Klamath Falls-Lakeview Hwy and 20 Newport-Corvallis Hwy/Corvallis-Lebanon Hwy/Corvallis-Albany Hwy/Santiam Hwy/McKenzie-Bend Hwy/Central Oregon Hwy
22 Crater Lake Hwy and 22 Three Rivers Hwy/Willamina-Salem Hwy/North Santiam Hwy
26 Mt Hood Hwy* and 26 Sunset Hwy/Mt Hood Hwy*/Warm Springs Hwy/Madras-Prineville Hwy/Ochoco Hwy/John Day Hwy
27 Alsea Hwy and 27 Crooked River Hwy
30 Willamina-Salem Hwy and: 30 Lower Columbia River Hwy/Columbia River Hwy/Historic Columbia River Hwy(x3)/Mosier-The Dalles Hwy/Pendleton Hwy/La Grande Baker Hwy(x2)/Ontario Spur; 30Byp Northeast Portland Hwy; 30B Huntington Hwy/Ontario Spur
31 Albany Corvallis Hwy and 31 Fremont Hwy
35 Coos Bay-Roseburg Hwy and 35 Mt Hood Hwy
36 Pendleton-Cold Springs Hwy and 36 Mapleton-Junction City Hwy
37 Wilson River Hwy and 37 Pendleton-Cold Springs Hwy and Pendleton-John Day Hwy
38 Oregon Caves Hwy and 38 Umpqua Hwy
39 Salmon River Hwy; 39Y McMinnville Spur and 39 Klamath Falls-Lakeview Hwy/Klamath Falls-Malin Hwy/Hatfield Hwy
42 Sherman Hwy and 42 Coos Bay-Roseburg Hwy; 42S Coquille-Bandon Hwy
43 Monmouth-Independence Hwy and 43 Oswego Hwy
46 Necanicum Hwy and 46 Oregon Caves Hwy
47 Sunset Hwy and 47 Mist-Clatskanie Hwy/Nehalem Hwy/TV Hwy
51 Wilsonville-Hubbard Hwy and 51 Monmouth-Independence Hwy/Independence Hwy
52 Heppner Hwy and 52 Payette Spur
53 Warm Springs Hwy and 53 Necanicum Hwy
58 Albany-Junction City Hwy and 58 Willamette Hwy
62 Florence-Eugene Hwy and 62 Crater Lake Hwy
66 La Grande-Baker Hwy and 66 Green Springs Hwy
70 McNary Hwy and 70 Dairy-Bonanza Hwy
82 McNary Hwy and 82 Wallowa Hwy
103 Fishhawk Falls Hwy signed as itself
104 Fort Stevens Hwy signed as itself
104Y Fort Stevens Spur would be signed as 104S
105 Warrenton-Astoria Hwy would be signed as 105; 105 Eugene-Sprinfield Hwy
120 Swift Hwy would be signed as 120
130 Little Nestuca Hwy signed as itself
131 Netarts Hwy signed as itself
138 North Umpqua Hwy signed as itself
141 Beaverton-Tualatin Hwy would be signed as 141
153 Belleview-Hopewell Hwy would be signed as 153
154 Lafayette Hwy would be signed as 154
155 Amity-Dayton Hwy would be signed as 155
173 Timberline Hwy would be signed as 173
180 Eddyville-Blodgett Hwy would be signed as 180
182 Otter Rock Hwy would be signed as 182
194 Monmouth Hwy would be signed as 194
200 Territorial Hwy would be signed as 200
201 Alsea-Deadwood Hwy and 201 Olds Ferry-Ontario Hwy/Succor Creek Hwy/Homedale Spur
205 East Portland Frwy and 205 French Glen Hwy
210 Corvallis-Lebanon Hwy and 210 Scholls Hwy
211 Albany-Lyons Hwy and 211 Woodburn-Estacada Hwy/Eagle Creek-Sandy Hwy
212 Halsey-Sweet Home Hwy and 212 Clackamas-Boring Hwy
222 Springfield-Creswell Hwy would be signed as 222
225 McVay Hwy would be signed as 225
226 Goshen-Divide Hwy and 226 Albany-Lyons Hwy
227 Eugene-Springfield Hwy and 227 Tiller-Trail Hwy
228 Springfield Hwy and 228 Halsey-Sweet Home Hwy
229 Mapleton-Junction City Hwy and 229 Siletz Hwy
230 Tiller-Trail Hwy and 230 West Diamond Lake Hwy
233 West Diamond Lake Hwy and 233 Lafayette Hwy/Amity-Dayton Hwy
234 Oakland-Shady Hwy and 234 Sams Valley Hwy
237 Myrtle Creek Hwy and 237 Cove Hwy/La Grande-Baker Hwy
240 Cape Arago Hwy and 240 Yamhill-Newburg Hwy
241 Coos River Hwy should be signed as itself
242 Powers Hwy and 242 McKenzie Hwy
244 Coquille-Bandon Hwy and 244 Ukiah-Hilgard Hwy
The following should be signed as themselves if not already:
250
251
255
260
273
281
282
293
331
332
334
335
339
350
351
361
370
372
380
402
410
413
414
420
422 (422Y -> 422S)
429
451
453
454
Title: Re: Which states allow number duplication?
Post by: jflick99 on April 23, 2018, 01:26:42 AM
At first I thought Kansas was one that did not allow it due to a number of state highways renumbered because of US and Interstate highways (24, 35, 69, 70, 135). Upon double checking, US 177 has 4 miles in Kansas to go along with a K-177. K-177 runs from Manhattan south to El Dorado, while US 177 ends in South Haven, 4 miles from Oklahoma. South Haven is about 60 miles southwest of El Dorado, so I can't imagine many people would mix them up.

It also appears that there were two separate K-150's in existence from 1955 to 1996, when the Olathe-Overland Park segment was decommissioned. The Marion-Elmdale segment has existed since 1937.
Title: Re: Which states allow number duplication?
Post by: froggie on April 23, 2018, 01:11:56 PM
Quote from: cl94 on April 22, 2018, 09:37:36 PM
Purposely excluded from my list of extensions because it's not an extension. It's a spur off of I-787. I-787 crosses the Collar City Bridge and ends in Troy.

One could also argue that 890 is a spur instead of an extension, since I-890 technically ends at the Thruway (per NYSDOT shapefiles).
Title: Re: Which states allow number duplication?
Post by: formulanone on April 23, 2018, 09:52:03 PM
Alabama originally tried to avoid route number duplication; US Routes did not have a state route of the same number. When Interstate routes were laid down, the state routes stayed the same (20, 22, 59, 65, 165)...though in most cases, they aren't close enough to be mixed up.

The only same-number route continuation is for I-759/AL 759 in Gadsden, which is entirely intentional.

County Route systems vary from county to county; they sometimes seem to avoid nearby routes, and other times, they do not (https://www.google.com/maps/@34.4853728,-87.4978587,3a,43.3y,277.87h,87.64t/data=!3m6!1e1!3m4!1s1XRroW1o5GUhUE_z4uRxyg!2e0!7i13312!8i6656).
Title: Re: Which states allow number duplication?
Post by: froggie on April 24, 2018, 10:53:31 AM
^ Huh...I was thinking more of the two County Road 20's that cross and even have interchanges with I-20/59, though I'm pretty sure the Greene County version (Exit 32/Boligee) still isn't signed at 20/59.
Title: Re: Which states allow number duplication?
Post by: formulanone on April 24, 2018, 12:37:47 PM
Quote from: froggie on April 24, 2018, 10:53:31 AM
^ Huh...I was thinking more of the two County Road 20's that cross and even have interchanges with I-20/59, though I'm pretty sure the Greene County version (Exit 32/Boligee) still isn't signed at 20/59.

That's right, at least one of them is signed: Exit 23 on I-20/59 is for CR 20. (https://www.google.com/maps/@32.7055222,-88.137992,3a,75y,229.4h,90.36t/data=!3m6!1e1!3m4!1sMhZZCSBKtQGAVPXX7fSglw!2e0!7i13312!8i6656)

Just passed by the CR43-near-US43 example last week, so it was in my head (couldn't get a good photo at 6am).
Title: Re: Which states allow number duplication?
Post by: mrpablue on April 24, 2018, 02:36:43 PM
Is Washington SR97 a thing, or is that an error on Maps?
Title: Re: Which states allow number duplication?
Post by: apeman33 on May 01, 2018, 06:56:59 PM
Quote from: jflick99 on April 23, 2018, 01:26:42 AM
At first I thought Kansas was one that did not allow it due to a number of state highways renumbered because of US and Interstate highways (24, 35, 69, 70, 135). Upon double checking, US 177 has 4 miles in Kansas to go along with a K-177. K-177 runs from Manhattan south to El Dorado, while US 177 ends in South Haven, 4 miles from Oklahoma. South Haven is about 60 miles southwest of El Dorado, so I can't imagine many people would mix them up.

It also appears that there were two separate K-150's in existence from 1955 to 1996, when the Olathe-Overland Park segment was decommissioned. The Marion-Elmdale segment has existed since 1937.

Kansas generally doesn't but U.S. 177/K-177 is the most obvious exception. There are also two sections of K-8 because the highway in between the two sections became a U.S. route. And for a short period of time there were two K-171s.

But the prime example of Kansas' preference to avoid duplication is K-152. It was K-35 but then I-35 came along, so it was renumbered K-135. Then I-35W was changed to I-135, so it was changed again to K-152. K-235 wasn't an option because I-235 already existed and at the time there were no K-3xx routes so they didn't want to go with K-335 (which itself would have been changed when I-335 was designated, anyway).

Edit: I think the only reason there were two K-150s was that the now decommissioned segment was numbered to match up with MO-150. But why they didn't change the other one, I don't know unless someone thought they were far enough apart that it wasn't an issue.
Title: Re: Which states allow number duplication?
Post by: kendancy66 on May 01, 2018, 07:27:56 PM
Quote from: WillWeaverRVA on April 16, 2018, 09:49:35 AM
Virginia does not typically allow duplication, although there are two three exceptions:

- VA 13 (http://www.vahighways.com/route-log/va013.htm) came into existence after US 13 was already around...in fact, there was already another VA 13 at the time (it was a state route extension of US 13, which did not yet exist on the mainland).

- VA 360 and US 360. (https://www.flickr.com/photos/willshighways/15415794562/in/album-72157648257859042/) VA 360 is an old alignment of US 360.

- US 33 and VA 33; VA 33 is a state route extension of US 33.

North Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).
Another exception is Sunset Lane in Annandale VA which is VA secondary route 895 which duplicates primary VA 895 toll road south of Richmond. Also since secondary routes in Virginia can duplicate in other counties there is a possibility that there may be other secondary routes numbered 895

SAMSUNG-SGH-I747

Title: Re: Which states allow number duplication?
Post by: WillWeaverRVA on May 01, 2018, 07:36:05 PM
Quote from: kendancy66 on May 01, 2018, 07:27:56 PM
Quote from: WillWeaverRVA on April 16, 2018, 09:49:35 AM
Virginia does not typically allow duplication, although there are two three exceptions:

- VA 13 (http://www.vahighways.com/route-log/va013.htm) came into existence after US 13 was already around...in fact, there was already another VA 13 at the time (it was a state route extension of US 13, which did not yet exist on the mainland).

- VA 360 and US 360. (https://www.flickr.com/photos/willshighways/15415794562/in/album-72157648257859042/) VA 360 is an old alignment of US 360.

- US 33 and VA 33; VA 33 is a state route extension of US 33.

North Carolina does not typically allow duplication except in cases where a state route number is assigned to a future interstate corridor (NC 140/I-140, NC 295/I-295, etc).
Another exception is Sunset Lane in Annandale VA which is VA secondary route 895 which duplicates primary VA 895 toll road south of Richmond. Also since secondary routes in Virginia can duplicate in other counties there is a possibility that there may be other secondary routes numbered 895

SAMSUNG-SGH-I747



Secondary routes don't count since every county has its own set, and every county with a SR 664, 785, and 895 duplicates the primary routes with those numbers.
Title: Re: Which states allow number duplication?
Post by: Mapmikey on May 01, 2018, 08:22:57 PM
The VA 664, 785, and 895 designations are indeed exceptions.  The secondary numbering system was specifically set up in 1933 to not duplicate primary route numbers, which is why all the VA 6xx, VA 7xx, and VA 8xx designations (100+ in total) in place at that time were renumbered.

It was also intentional that the secondary numbers repeated in all the counties.