So, we know that in concurrencies, there's always a primary route, and the mileposts that are used are based on what the primary route is. The other route(s), however, is/are still counting, you just don't see it. So, if State Route begins a concurrency with US Route at State Route milepost 50 and US Route milepost 200, and the concurrency lasts for 30 miles, when the concurrency ends at US Route milepost 230, the next milepost after the split for State Route would be milepost 81, not milepost 51.
We can tell which route is the primary route based on which one comes first on the reassurance shields, whether it's on top or on the left. Here (https://goo.gl/maps/hGjZARSpcg7ux1yY6), for example, Interstate 82 is the primary route, since its reassurance shield is on top. Likewise here (https://goo.gl/maps/Hmo7cm6g78MvHExr9) for US Route 97 and Washington State Route 20. This one (https://goo.gl/maps/G81zgBN2zoJRf6Jo7) is the same thing, but instead of top to bottom, it's left to right. And here (https://goo.gl/maps/SMW4GQCLK95CLvjB6), the primary route is Interstate 82, the secondary route is US Route 12, and the tertiary route is US Route 97. Likewise, here (https://goo.gl/maps/R1QWXJDCYkWd5Ne69), the primary route is Interstate 90, the secondary route is US Route 2, and the tertiary route is US Route 395.
We also know that the importance goes interstates >> US highways >> state highways. So, my question is when the concurrency involves two or more of the same type of route, how is it determined which one is the primary route? Here (https://goo.gl/maps/AcNefGF1QnhWSfKD9), SR 20 and SR 21 are both local state highways, with SR 20 being the primary/more important route. In Montana, there's a concurrency with Interstate 15 and Interstate 90, and Interstate 15 is considered to be the primary/more important route.
I've generally seen lower numbers get priority. But it's by no means a consistent rule.
I-64 has concurrencies with five odd north-south Interstate highways between St. Louis and the Hampton Roads area. They are I-57, I-75, I-77, I-81, and I-95. Each concurrency uses the odd number Interstate's mileposts and exit numbers–more than likely because each of the odd number Interstates were completed before I-64 was. However, in four of the five cases the higher numbered Interstate's milepost and exit numbers were used.
Another example is I-20/I-59 in Mississippi. I-59's mileposts and exit numbers are used.
Quote from: Amaury on October 04, 2022, 01:49:25 AM
We can tell which route is the primary route based on which one comes first on the reassurance shields, whether it's on top or on the left.
This isn't really reliable. In California, concurrencies technically do not exist at all. You have implied concurrencies, i.e. one route will exist but not signed. This isn't very consistent and more often than not, they do seem to be signed, but the order doesn't make sense. For example, during the brief CA-23/US-101 concurrency (more technically, CA-23 doesn't exist for a few miles while 101 bridges the gap), new signage in this area actually puts the 23 shield on top of the 101 shield. Not side to side. If anything, 101 shields should be on top. But they aren't. But then when you see CA-168/US-395, they are lined up side to side.
Quote from: amroad17 on October 04, 2022, 03:49:10 AM
I-64 has concurrencies with five odd north-south Interstate highways between St. Louis and the Hampton Roads area. They are I-57, I-75, I-77, I-81, and I-95. Each concurrency uses the odd number Interstate's mileposts and exit numbers–more than likely because each of the odd number Interstates were completed before I-64 was. However, in four of the five cases the higher numbered Interstate's milepost and exit numbers were used.
Another example is I-20/I-59 in Mississippi. I-59's mileposts and exit numbers are used.
And yet, the MUTCD has guidelines regarding which mileposts are used.
Quote from: Amaury on October 04, 2022, 01:49:25 AM
So, we know that in concurrencies, there's always a primary route, and the mileposts that are used are based on what the primary route is. The other route(s), however, is/are still counting, you just don't see it. So, if State Route begins a concurrency with US Route at State Route milepost 50 and US Route milepost 200, and the concurrency lasts for 30 miles, when the concurrency ends at US Route milepost 230, the next milepost after the split for State Route would be milepost 81, not milepost 51.
This is not true in Utah, where state route mileage does not increase over concurrencies.
Along the Spine in North Carolina, I-40 uses I-85 mile markers because I-85 was there first. I-74 uses the I-73 mile markers probably due to the north-south nature of the US-220 entire corridor. But if you believe the signage plans, the northern end of I-77 might change over to use I-74 mile markers starting at the Virginia State Line. (I'll believe it when I see it).
I see no reason to use the lower number. I would rather use the main route. For example, I-64 takes a jog when it overlaps I-81, while I-81's route is unaffected by the I-64 overlap.
There's not always a main route, though, e.g. I-75/85 in Atlanta.
The Kansas Turnpike uses four different Interstate route numbers along its route: I-35, I-335, I-470, I-70.
The 0-mile of I-35 is at the Oklahoma state line, and the mileposts remain consistent while it is concurrent with the Turnpike.
Where I-35 splits off from the Turnpike (at Emporia), its mileposts continue as expected. Continuing on the Turnpike instead would be the theoretical 0-mile of I-335. However, the exit numbers do not reset: Emporia is Exit #127 for both I-35 and I-335. There are no mileposts for I-335 below #127. This means that the mileposts for the Turnpike remain consistent, and those for I-35 conveniently do as well.
But, at Topeka, it becomes abundantly clear that the Turnpike is the "primary" route when it comes to mileposts.
I-470's exits:
#1—#6 – western terminus to Topka Blvd exit
#177—#183 – concurrency with the Turnpike
I-70's exits:
#1—#366 – Colorado state line to K-4 exit
#183—#224 – concurrency with the Turnpike
#410—#423 – 110th St exit to Missouri state line
Interestingly, there are no duplicate exit numbers on I-70 in Kansas, but theoretically there could be.
For concurrencies of two interstates, there isn't a pattern and it's up to each agency. But from my observations, a lot of cases have the longer route in the state getting the exit numbers.
Lots of exceptions to this like a historical reason that one route was here before the other (I-40/85), one of them clearly exits on both sides from the other (I-70/71, concurrency is in a E-W direction), etc.
With the above, I think the two I-90/94 concurrencies for which set of exit numbers to use are flipped; WI should've been with I-94's, and IL with I-90's.
Quote from: amroad17 on October 04, 2022, 03:49:10 AM
I-64 has concurrencies with five odd north-south Interstate highways between St. Louis and the Hampton Roads area. They are I-57, I-75, I-77, I-81, and I-95. Each concurrency uses the odd number Interstate's mileposts and exit numbers–more than likely because each of the odd number Interstates were completed before I-64 was. However, in four of the five cases the higher numbered Interstate's milepost and exit numbers were used.
Another example is I-20/I-59 in Mississippi. I-59's mileposts and exit numbers are used.
Note that the short part of the I-55/64 concurrency in MO uses I-64's exit numbers WB (no exits EB), one exception for I-64 that I see a lot of people miss.
Quote from: amroad17 on October 04, 2022, 03:49:10 AM
I-64 has concurrencies with five odd north-south Interstate highways between St. Louis and the Hampton Roads area. They are I-57, I-75, I-77, I-81, and I-95. Each concurrency uses the odd number Interstate's mileposts and exit numbers–more than likely because each of the odd number Interstates were completed before I-64 was. However, in four of the five cases the higher numbered Interstate's milepost and exit numbers were used.
Another example is I-20/I-59 in Mississippi. I-59's mileposts and exit numbers are used.
Just for the sake of nitpicking (because that's what we do here ;-)), the I-64/77 concurrency is slightly more complicated in that since their mileposts ascend in opposite directions during the overlap, I-64 has the higher mileposts at the Beckley end while I-77 has the higher mileposts at the Charleston end. The "balance point" is roughly milepost 80 near the Chelyan toll plaza.
The I-15/90 concurrency in Montana is dumb. I-90 is set up as the through route at the interchanges at both ends, and 90 almost certainly has more traffic than 15. But mileposts and exit numbers use I-15 mileage, and the interstate spur into Butte is designated I-115.
In Wisconsin, the section of I-39 just north of I-90/94 has four exits that don't correspond to I-39's mileage at all - they are kind of numbered as if US-51 was duplexed with that section.
When US-51 begins its duplex with I-39 at the fifth exit, the exit numbers used are based on US-51's mileage.
I-39 is the first sign on all reassurance markers though.
In CT, the more well known route usually gets the mileage (but not necessarily markers), with interstates trumping all. Here's a few significant ones:
US 5/CT 15: Uses CT 15 mileage
CT 8/25: Uses CT 8 enhanced mile markers (though they begin at the same point)
US 44/202 and US 202/CT 10: Neither uses US 202 mileage
US 6/44: Uses US 6 mileage
US 7/202: Uses US 7 mileage
US 7/44: Uses US 44 mileage since it's generally East-west)
CT 2/32: Uses CT 2 mileage
The Penna Turnpike is followed by four different Interstates: I-76, I-70, I-276 and I-95. Between New Stanton and Breezewood (the two endpoints for the I-70 concurrency), I-76's mileposts and exit numbers are used. They continue to increase after I-76 leaves to enter Philadelphia and I-276 begins bypassing to the north, and even when I-95 comes in to cross the Delaware and join the NJTP on the other side.
In Indiana, both I-90 and I-94 take priority over I-80 as I-80 is entirely concurrent throughout the state.
I-65 takes priority over I-70 in Indy.
I-465 takes priority over I-74 (and I-69 when signed).
Quote from: SkyPesos on October 04, 2022, 09:40:55 AM
For concurrencies of two interstates, there isn't a pattern and it's up to each agency. But from my observations, a lot of cases have the longer route in the state getting the exit numbers.
Lots of exceptions to this like a historical reason that one route was here before the other (I-40/85), one of them clearly exits on both sides from the other (I-70/71, concurrency is in a E-W direction), etc.
With the above, I think the two I-90/94 concurrencies for which set of exit numbers to use are flipped; WI should've been with I-94's, and IL with I-90's.
The 90/94 concurrency in Wisconsin is a toss-up to me. Neither route feels like the main route. In Illinois, I-90 "joins" I-94 on both ends. At least, that's what it feels like to me. I'm also biased considering whenever I head downtown it's on 94.
The one that I do find weird, but also understandable given how 294 should connect back to 94 and the tollway being involved, is the I-294/I-80 concurrency.
Quote from: JoePCool14 on October 04, 2022, 03:32:16 PM
The 90/94 concurrency in Wisconsin is a toss-up to me. Neither route feels like the main route. In Illinois, I-90 "joins" I-94 on both ends. At least, that's what it feels like to me. I'm also biased considering whenever I head downtown it's on 94.
I would still go with I-94's exit numbers in Wisconsin as it's mileage in the concurrency is 147-240, while I-90's is 45-138. Less repeated exit numbers when you're following I-90, while if you're following I-94 west to east and the concurrency uses I-90's exit numbers, you're repeating all mileage that you passed already. And I would imagine traffic to the Twin Cities on the western end to be more than whatever I-90 takes.
As for IL, with I-94 leaving the concurrencies on the right at both ends, it feels more to me that it's I-94 joining I-90. And I-94's mileage in IL gets nowhere close to the 85-100 range (what the concurrency exit numbers would be between if it used I-90's exit numbers.
This is also why I think the I-75/85 concurrency using I-75's exit numbers make a lot of sense, as I-85 doesn't get to the mid-200s exit numbers on its own in Georgia.
Quote from: SkyPesos on October 04, 2022, 04:41:48 PM
Quote from: JoePCool14 on October 04, 2022, 03:32:16 PM
The 90/94 concurrency in Wisconsin is a toss-up to me. Neither route feels like the main route. In Illinois, I-90 "joins" I-94 on both ends. At least, that's what it feels like to me. I'm also biased considering whenever I head downtown it's on 94.
I would still go with I-94's exit numbers in Wisconsin as it's mileage in the concurrency is 147-240, while I-90's is 45-138. Less repeated exit numbers when you're following I-90, while if you're following I-94 west to east and the concurrency uses I-90's exit numbers, you're repeating all mileage that you passed already. And I would imagine traffic to the Twin Cities on the western end to be more than whatever I-90 takes.
While it's true that there is more traffic following I-94 than I-90 at the "northern end" of the concurrency near Tomah, the opposite is true at the southern end near Madison.
And the situation you describe with repeating exit numbers would occur for I-90 if you are heading westbound and using I-94's exit numbers. It's a situation that can't be avoided no matter the choice.
The New York Thruway's mileposts are apparently more important than those of the Interstate routes that travel on it. Interestingly enough, the mileposts and exit numbers do reset on both I-90 and I-87, unlike the Kansas Turnpike situation mentioned upthread. And due to the Thruway's unorthodox directional routing, the mileposts start out okay at the southern end, but once you get to the east-west section what ends up happening is [pause to catch your breath] the mileposts are ascending backwards, with mile 120 or whatever in the Albany area, and mile 450 or whatever at Ripley at the PA line.
In Tennessee the US Highway concurrencies are based upon the secret concurrent state route that has through precedence. So SR 1 would be the mileage used for the concurrency of US 41 & US 70S. For the short US 31/Business US 412 the through route is SR 7 until the split to SR 6.
However, the split has just changed so that the through route for the concurrency is now SR 7 as US 412 splits of where SR 7 now splits. SR 7 used to split off earlier and SR 6 took over, still with a precedence over SR 99. The SR for US 412 is SR 99. SR 99's mileage picks back up after the split (on both ends).
Quote from: Henry on October 04, 2022, 03:08:21 PM
The Penna Turnpike is followed by four different Interstates: I-76, I-70, I-276 and I-95. Between New Stanton and Breezewood (the two endpoints for the I-70 concurrency), I-76's mileposts and exit numbers are used. They continue to increase after I-76 leaves to enter Philadelphia and I-276 begins bypassing to the north, and even when I-95 comes in to cross the Delaware and join the NJTP on the other side.
FYI, former exit 358 is now exit 42 (https://www.google.com/maps/@40.1252315,-74.8658994,3a,58y,96.95h,97.79t/data=!3m6!1e1!3m4!1sjQd6IWIzgDJ5htmlxaoMLw!2e0!7i16384!8i8192).
Kentucky does not officially recognize concurrencies. The lower number of two routes on the same system always takes precedence. And mile markers for all routes except interstates and parkways reset at county lines.
The best instance I can think of where the lower-numbered route takes precedence is in Letcher County in the Isom community near the Knott County line. KY 15 is obviously the through route, and it has a signed concurrency with KY 160. But there is also a short concurrency with KY 7. That section of road is officially known as KY 7 in the official route logs and any mile markers posted would carry KY 7's mileage. Mileage stops and restarts at the intersections where the concurrencies begin and end. Good example is KY 11 and KY 15, which have a concurrency that runs most of the east-west length of Powell County. Both routes enter northbound from Wolfe County and intersect at Slade, adjacent to the Mountain Parkway's Exit 33. The concurrency through Stanton and Clay City carries KY 11's mileage. KY 15's mileage is "suspended," if you will, resumes where KY 11 north splits off. So you're about 20 miles into Powell County from Wolfe on KY 15 but the mile markers start counting up from around 4 or so.
The obvious exception to the "lower number on two same systems" rule is I-75 and I-64.
Quote from: Quillz on October 04, 2022, 03:28:32 AM
I've generally seen lower numbers get priority. But it's by no means a consistent rule.
Nevada follows this rule consistently, along with the Interstate > US route rule.
US 6 is mileposted all the way across the state.
US 50 is mileposted except for its concurrency with I-580 in Carson City and with US 6 east of Ely.
US 93 is mileposted except for its concurrencies with interstates in Clark County, with US 6 and 50 east of Ely and with US 50 in Ely.
Et cetera. US 95 is arguably the most significant US route in the state but it has several milepost gaps.
In Utah, as in most places, interstates take priority over US routes which take priority over state routes. Overlaps between equal route types will generally use the mileage of whichever route carries a greater amount of through traffic, is more significant/recognizable, or is clearly set up as the through route. This usually winds up giving the lower numbered route priority anyway but that is not always the case. We have:
I-15/I-80
I-15/I-84
US 6/US 50 - while both routes share the same mileage here, the overlap is inventoried and legislated as part of US 6
US 6/US 89
US 6/US 191
US 40/US 189
US 40/US 191
US 50/US 89
US 89/US 91
US 163/US 191 - 163 is unsigned, but this does exist per UDOT materials
SR 48/SR 68
SR 68/SR 85
SR 118/SR 120
One noteworthy thing is that business loops are entirely unofficial in Utah, and mileposts on them are entirely related to the state or US highway they overlap (or, for the two locally maintained business loops in the state, simply don't exist). This is in contrast to states like Idaho, where business loops are their own thing and their mileage trumps even any US highways they might be concurrent with.
In Virginia, I-64 has to use I-81's exit numbers as it enters and leaves I-81.
Quote from: hbelkins on October 04, 2022, 11:14:45 PM
Kentucky does not officially recognize concurrencies. The lower number of two routes on the same system always takes precedence. And mile markers for all routes except interstates and parkways reset at county lines.
The best instance I can think of where the lower-numbered route takes precedence is in Letcher County in the Isom community near the Knott County line. KY 15 is obviously the through route, and it has a signed concurrency with KY 160. But there is also a short concurrency with KY 7. That section of road is officially known as KY 7 in the official route logs and any mile markers posted would carry KY 7's mileage. Mileage stops and restarts at the intersections where the concurrencies begin and end. Good example is KY 11 and KY 15, which have a concurrency that runs most of the east-west length of Powell County. Both routes enter northbound from Wolfe County and intersect at Slade, adjacent to the Mountain Parkway's Exit 33. The concurrency through Stanton and Clay City carries KY 11's mileage. KY 15's mileage is "suspended," if you will, resumes where KY 11 north splits off. So you're about 20 miles into Powell County from Wolfe on KY 15 but the mile markers start counting up from around 4 or so.
The obvious exception to the "lower number on two same systems" rule is I-75 and I-64.
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontiguous routes? I'm not so sure.
Sounds like the log is more about keeping track of milepoints for determining the limits of capital projects (e.g., since FMIS/FHWA require funding by asset in projects) rather than route recognition. If you have duplicate mileposts, your developers/designers don't know what to enter into your systems (which FMIS couldn't handle anyway) and then you double count the project accomplishments on the back end even if you could. One set of mileposts per segment just keeps things simpler, despite concurrencies. NYSDOT's reference markers/mileposts work similarly.
Quote from: Rothman on October 05, 2022, 06:57:20 AM
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontiguous routes? I'm not so sure.
Sounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
Quote from: vdeane on October 04, 2022, 08:50:08 PM
Quote from: Henry on October 04, 2022, 03:08:21 PM
The Penna Turnpike is followed by four different Interstates: I-76, I-70, I-276 and I-95. Between New Stanton and Breezewood (the two endpoints for the I-70 concurrency), I-76's mileposts and exit numbers are used. They continue to increase after I-76 leaves to enter Philadelphia and I-276 begins bypassing to the north, and even when I-95 comes in to cross the Delaware and join the NJTP on the other side.
FYI, former exit 358 is now exit 42 (https://www.google.com/maps/@40.1252315,-74.8658994,3a,58y,96.95h,97.79t/data=!3m6!1e1!3m4!1sjQd6IWIzgDJ5htmlxaoMLw!2e0!7i16384!8i8192).
Can't believe I overlooked that one! Of course, there was no interchange between I-95 and the Turnpike until the former was rerouted to follow the latter, so that may be an exception.
Quote from: Quillz on October 05, 2022, 07:47:20 AM
Quote from: Rothman on October 05, 2022, 06:57:20 AM
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontiguous routes? I'm not so sure.
Sounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
Wisconsin would be a state that's pretty thorough about signing concurrencies. Doesn't matter if it's an expressway, freeway, or 2-lane road.
An example of how WisDOT handles mileage on a non-interstate would be US-151 in the SW region. It carries STH-35 and US-51 over/near the border with Iowa before they split off before Dickeyville. And then later, it's concurrent with US-18 towards Madison. US-151, despite being a higher number than both other US route designations, takes the lead when it comes to mileage. Granted, US-151 is an expressway/freeway throughout this area, so it's logical to do this.
All routes are signed well on all segments though.
Quote from: Quillz on October 05, 2022, 07:47:20 AMSounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
I can definitely confirm Washington signs their concurrencies, as per my OP. LOL
Quote from: Rothman on October 05, 2022, 06:57:20 AM
Quote from: hbelkins on October 04, 2022, 11:14:45 PM
Kentucky does not officially recognize concurrencies. The lower number of two routes on the same system always takes precedence. And mile markers for all routes except interstates and parkways reset at county lines.
The best instance I can think of where the lower-numbered route takes precedence is in Letcher County in the Isom community near the Knott County line. KY 15 is obviously the through route, and it has a signed concurrency with KY 160. But there is also a short concurrency with KY 7. That section of road is officially known as KY 7 in the official route logs and any mile markers posted would carry KY 7's mileage. Mileage stops and restarts at the intersections where the concurrencies begin and end. Good example is KY 11 and KY 15, which have a concurrency that runs most of the east-west length of Powell County. Both routes enter northbound from Wolfe County and intersect at Slade, adjacent to the Mountain Parkway's Exit 33. The concurrency through Stanton and Clay City carries KY 11's mileage. KY 15's mileage is "suspended," if you will, resumes where KY 11 north splits off. So you're about 20 miles into Powell County from Wolfe on KY 15 but the mile markers start counting up from around 4 or so.
The obvious exception to the "lower number on two same systems" rule is I-75 and I-64.
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontiguous routes? I'm not so sure.
Sounds like the log is more about keeping track of milepoints for determining the limits of capital projects (e.g., since FMIS/FHWA require funding by asset in projects) rather than route recognition. If you have duplicate mileposts, your developers/designers don't know what to enter into your systems (which FMIS couldn't handle anyway) and then you double count the project accomplishments on the back end even if you could. One set of mileposts per segment just keeps things simpler, despite concurrencies. NYSDOT's reference markers/mileposts work similarly.
Newer versions of the map don't include concurrencies. Older maps clearly show concurrencies like KY 11/KY 15 and US 25/421, but more recent maps show only the lower-numbered route -- both state maps and the individual county maps.
At least one highway district -- Somerset-based D-8 -- has begun signing what would normally be signed as concurrencies elsewhere as "To Route NN."
Quote from: JoePCool14 on October 05, 2022, 11:30:10 AM
Wisconsin would be a state that's pretty thorough about signing concurrencies. Doesn't matter if it's an expressway, freeway, or 2-lane road.
An example of how WisDOT handles mileage on a non-interstate would be US-151 in the SW region. It carries STH-35 and US-61 over/near the border with Iowa before they split off before Dickeyville. And then later, it's concurrent with US-18 towards Madison. US-151, despite being a higher number than both other US route designations, takes the lead when it comes to mileage. Granted, US-151 is an expressway/freeway throughout this area, so it's logical to do this.
All routes are signed well on all segments though.
Slight correction
Quote from: Big John on October 05, 2022, 04:48:36 PM
Quote from: JoePCool14 on October 05, 2022, 11:30:10 AM
Wisconsin would be a state that's pretty thorough about signing concurrencies. Doesn't matter if it's an expressway, freeway, or 2-lane road.
An example of how WisDOT handles mileage on a non-interstate would be US-151 in the SW region. It carries STH-35 and US-61 over/near the border with Iowa before they split off before Dickeyville. And then later, it's concurrent with US-18 towards Madison. US-151, despite being a higher number than both other US route designations, takes the lead when it comes to mileage. Granted, US-151 is an expressway/freeway throughout this area, so it's logical to do this.
All routes are signed well on all segments though.
Slight correction
Thank you, I thought 51 sounded wrong when I was writing that. Guess I'm too tired then!
I believe there is only one freeway-freeway concurrency (Highway 403 and the QEW) in Ontario.
In this case it follow's the QEW's mileage, presumably because that was the original QEW right-of-way.
Quote from: Quillz on October 05, 2022, 07:47:20 AM
Quote from: Rothman on October 05, 2022, 06:57:20 AM
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontinuous routes? I'm not so sure.
Sounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
Georgia is notorious for signing concurrencies to an excessive degree in most respects. They just are terrible with signing the few Business Interstate routes that they have.
Quote from: Dirt Roads on October 04, 2022, 09:14:21 AM
Along the Spine in North Carolina, I-40 uses I-85 mile markers because I-85 was there first. I-74 uses the I-73 mile markers probably due to the north-south nature of the US-220 entire corridor. But if you believe the signage plans, the northern end of I-77 might change over to use I-74 mile markers starting at the Virginia State Line. (I'll believe it when I see it).
whats funny is that I-40 is the more heavily traveled route by far, on either end of the concurrency.
Quote from: Avalanchez71 on October 05, 2022, 11:40:27 PM
Quote from: Quillz on October 05, 2022, 07:47:20 AM
Quote from: Rothman on October 05, 2022, 06:57:20 AM
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontinuous routes? I'm not so sure.
Sounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
Georgia is notorious for signing concurrencies to an excessive degree in most respects. They just are terrible with signing the few Business Interstate routes that they have.
I've found GA's signage to be lacking, actually, with those overhead span wire signs missing routes and the like.
They do sign their state routes which duplicate U.S. routes and the like, but trying to follow a certain route from start to finish can be a fun challenge.
See also MA and the limitations of their SGSes.
Quote from: Rothman on October 06, 2022, 07:00:39 AM
Quote from: Avalanchez71 on October 05, 2022, 11:40:27 PM
Quote from: Quillz on October 05, 2022, 07:47:20 AM
Quote from: Rothman on October 05, 2022, 06:57:20 AM
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontinuous routes? I'm not so sure.
Sounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
Georgia is notorious for signing concurrencies to an excessive degree in most respects. They just are terrible with signing the few Business Interstate routes that they have.
I've found GA's signage to be lacking, actually, with those overhead span wire signs missing routes and the like.
They do sign their state routes which duplicate U.S. routes and the like, but trying to follow a certain route from start to finish can be a fun challenge.
See also MA and the limitations of their SGSes.
Yeah, I'm not a fan of the GA overhead spanwires, especially because the signs will slide around on them in the wind (or fall off) over the years. It can be quite difficult to figure out if what you're seeing is telling you to stay straight for whatever route or if there's a turn it's telling you to take.
In my experience around GA and north FL though, I do think Georgia has better signage. Florida tends to omit a lot of reassurance shields from places where they would be helpful and would exist in GA.
Quote from: andrepoiy on October 05, 2022, 10:08:22 PM
I believe there is only one freeway-freeway concurrency (Highway 403 and the QEW) in Ontario.
In this case it follow's the QEW's mileage, presumably because that was the original QEW right-of-way.
Plus the intended alignment of 403 was actually built as part of 407.
Quote from: US 89 on October 06, 2022, 08:37:50 AM
Quote from: Rothman on October 06, 2022, 07:00:39 AM
Quote from: Avalanchez71 on October 05, 2022, 11:40:27 PM
Quote from: Quillz on October 05, 2022, 07:47:20 AM
Quote from: Rothman on October 05, 2022, 06:57:20 AM
So, they don't officially recognize them but they shield them anyway? KY has a whole lot of discontinuous routes? I'm not so sure.
Sounds like it, yes. California is the same way: there are many non-contiguous routes because concurrencies do not technically exist. CA-1 is broken into several alignments because of US-101, for example. If there is signage (and it's very inconsistent), it's just for motorist aid. I don't know if other states operate that way, seems most others will sign concurrencies (to an excessive degree).
Georgia is notorious for signing concurrencies to an excessive degree in most respects. They just are terrible with signing the few Business Interstate routes that they have.
I've found GA's signage to be lacking, actually, with those overhead span wire signs missing routes and the like.
They do sign their state routes which duplicate U.S. routes and the like, but trying to follow a certain route from start to finish can be a fun challenge.
See also MA and the limitations of their SGSes.
Yeah, I'm not a fan of the GA overhead spanwires, especially because the signs will slide around on them in the wind (or fall off) over the years. It can be quite difficult to figure out if what you're seeing is telling you to stay straight for whatever route or if there's a turn it's telling you to take.
In my experience around GA and north FL though, I do think Georgia has better signage. Florida tends to omit a lot of reassurance shields from places where they would be helpful and would exist in GA.
There are no signs at in Steinhatchee, FL.
Quote from: Avalanchez71 on October 05, 2022, 11:40:27 PM
Georgia is notorious for signing concurrencies to an excessive degree in most respects.
I used to think that signing all concurrencies was a good idea. But now I kind of prefer the less-is-more approach, especially when there's a clear instance of one route/number being far more traveled than the others. Especially some places like Arizona and Colorado that will sign their US routes concurrent with their interstates across the entire state, it just seems unnecessary at that point. I think Oregon has the right approach of not signing concurrencies for redundant routes, instead using them as business loops where they'll have unique mileage.
Quote from: Quillz on October 07, 2022, 07:41:12 AM
Especially some places like Arizona and Colorado that will sign their US routes concurrent with their interstates across the entire state, it just seems unnecessary at that point.
Huh? Colorado is at or near the top of the list for worst concurrency signage in the US. There are no standing US 87 shields in the state. Good luck following US 6 or US 85 through Denver without signs…
Quote from: Quillz on October 07, 2022, 07:41:12 AM
Quote from: Avalanchez71 on October 05, 2022, 11:40:27 PM
Georgia is notorious for signing concurrencies to an excessive degree in most respects.
I used to think that signing all concurrencies was a good idea. But now I kind of prefer the less-is-more approach, especially when there's a clear instance of one route/number being far more traveled than the others. Especially some places like Arizona and Colorado that will sign their US routes concurrent with their interstates across the entire state, it just seems unnecessary at that point. I think Oregon has the right approach of not signing concurrencies for redundant routes, instead using them as business loops where they'll have unique mileage.
The problem with Georgia is how so many of their routes are concurrent in the first place. You shouldn't have all these instances where 4 routes share the same stretch of road. Split some of them up and give each segment new numbers.
Quote from: Henry on October 05, 2022, 10:17:56 AM
Quote from: vdeane on October 04, 2022, 08:50:08 PM
Quote from: Henry on October 04, 2022, 03:08:21 PM
The Penna Turnpike is followed by four different Interstates: I-76, I-70, I-276 and I-95. Between New Stanton and Breezewood (the two endpoints for the I-70 concurrency), I-76's mileposts and exit numbers are used. They continue to increase after I-76 leaves to enter Philadelphia and I-276 begins bypassing to the north, and even when I-95 comes in to cross the Delaware and join the NJTP on the other side.
FYI, former exit 358 is now exit 42 (https://www.google.com/maps/@40.1252315,-74.8658994,3a,58y,96.95h,97.79t/data=!3m6!1e1!3m4!1sjQd6IWIzgDJ5htmlxaoMLw!2e0!7i16384!8i8192).
Can't believe I overlooked that one! Of course, there was no interchange between I-95 and the Turnpike until the former was rerouted to follow the latter, so that may be an exception.
the mileposts also follow I-95 now (https://www.google.com/maps/@40.12547,-74.8674445,3a,90y,105.91h,105.48t/data=!3m7!1e1!3m5!1sAF1QipPmGQwfnOAfzsSzMY1yVjb_XZ4KG6AUx5sXKiaE!2e10!3e11!7i7680!8i3840) (IIRC, there was a period when they didn't).
Quote from: Quillz on October 04, 2022, 06:12:48 AM
Quote from: Amaury on October 04, 2022, 01:49:25 AM
We can tell which route is the primary route based on which one comes first on the reassurance shields, whether it's on top or on the left.
This isn't really reliable. In California, concurrencies technically do not exist at all. You have implied concurrencies, i.e. one route will exist but not signed. This isn't very consistent and more often than not, they do seem to be signed, but the order doesn't make sense. For example, during the brief CA-23/US-101 concurrency (more technically, CA-23 doesn't exist for a few miles while 101 bridges the gap), new signage in this area actually puts the 23 shield on top of the 101 shield. Not side to side. If anything, 101 shields should be on top. But they aren't. But then when you see CA-168/US-395, they are lined up side to side.
This does not make sense. The 5/10 concurrency in downtown L.A. clearly exists, as does the 405/22 concurrency in Seal Beach.
Quote from: dbz77 on November 11, 2022, 09:00:20 PM
This does not make sense. The 5/10 concurrency in downtown L.A. clearly exists, as does the 405/22 concurrency in Seal Beach.
It makes sense in the following fashion. Each highway in California has a legal definition in the Streets & Highways Code. What we all I-5 is "Route 5", US 101 is "Route 101" and both SR 8 and I-8 are just parts of "Route 8" that use different signs. These legal definitions don't overlap, so there is a gap in one route's legal definition when it overlaps another route. Caltrans may sign a concurrency to connect the sections on either side of a gap, but the route doesn't technically exist there.
Quote from: US 89 on October 07, 2022, 08:17:50 AM
Quote from: Quillz on October 07, 2022, 07:41:12 AM
Especially some places like Arizona and Colorado that will sign their US routes concurrent with their interstates across the entire state, it just seems unnecessary at that point.
Huh? Colorado is at or near the top of the list for worst concurrency signage in the US. There are no standing US 87 shields in the state. Good luck following US 6 or US 85 through Denver without signs...
No one:
Colorado: What are concurrencies?
Quote from: kirbykart on October 04, 2022, 06:20:49 PM
The New York Thruway's mileposts are apparently more important than those of the Interstate routes that travel on it. Interestingly enough, the mileposts and exit numbers do reset on both I-90 and I-87, unlike the Kansas Turnpike situation mentioned upthread. And due to the Thruway's unorthodox directional routing, the mileposts start out okay at the southern end, but once you get to the east-west section what ends up happening is [pause to catch your breath] the mileposts are ascending backwards, with mile 120 or whatever in the Albany area, and mile 450 or whatever at Ripley at the PA line.
I-87 technically has 4 and I-90 has 3 different sets of Mileposts. I-87 has the Deegan (about 8 miles), the Thruway mainline (MP 0-MP 148), a brief concurrency with I-90 (using one set of I-90's mileposts), then the Northway (about 185 miles). I-90 has the Thruway mainline (347 miles, but signed MP 496-MP 149), Free 90 (briefly concurrent with I-87; 21 miles), and then the Berkshire Spur (18 miles, marked B6-B24, as it measures from the I-87 junction).
Texas is generally pretty good about signing concurrencies:: case in point-the US 69/US 96/US 287 triplex in and around Beaumont, or any of the I-10/US 90 multiplexes. Or the I-410/TX 16/TX 130 in San Antonio.
One notable exception is the complete lack of any acknowledgment that I-10 and US 90 are concurrent through Houston from the east loop until far west Katy. For some reason, there are no signs that you're also on US 90. It's odd because in San Antonio, I-10 and US 90, and I-10 and US 87; as well as I-37 and US 281 are all very well signed, as are the numerous other concurrent routes in the San Antonio region. Even in Houston, I-69 and US 59 are signed concurrent, but then again the I-69 designation is new.
Oddly enough many of the signs actually are signed US 59/I-69
I-80 and I-90 are concurrent when entering OH from IN, so the milemarkers correspond to both.
(https://i.imgur.com/v8aU47e.jpg)
Quote from: theroadwayone on November 12, 2022, 03:11:21 AM
Colorado: What are concurrencies?
CO-9: They're these things:
https://goo.gl/maps/76BEPjjRCiAEGAhw5
https://goo.gl/maps/fwFPpx9yAxSxPRmdA
https://goo.gl/maps/ZEfyQ2b8LZkhCL8q6
I couldn't find the thread about wrong way concurrencies, so I'm posting it here. QC 122 has a very short wrong way concurrency with QC 224, lasting only 300 feet:
(https://live.staticflickr.com/65535/52540632061_abb7d44803.jpg) (https://flic.kr/p/2o3Qtqz)QC 122 EB at QC 224 - 1 (https://flic.kr/p/2o3Qtqz) by Liliana Vess (https://www.flickr.com/photos/lilianauwu/), on Flickr
(https://live.staticflickr.com/65535/52541183003_f8e5ef8175.jpg) (https://flic.kr/p/2o3Ticz)QC 122 EB at QC 224 - 2 (https://flic.kr/p/2o3Ticz) by Liliana Vess (https://www.flickr.com/photos/lilianauwu/), on Flickr
(The concurrency on Google Maps (https://maps.app.goo.gl/nKkh4tUgthem9Fps7?g_st=ic))
WV normally uses the lowest-number highest-ranked route for inventory purposes, but there are a couple exceptions:
- During their multiplex, I-77 is considered the primary route over I-64.
- US 48 is never the inventory route when it is running concurrent with another US route, even though Corridor-style mile markers are present for Corridor H (US 48) throughout. This is the case for the US 33 concurrency between Weston and Elkins, which makes sense since US 33 is the lower number. When US 33 leaves, US 48 is very briefly the inventory route because it is not concurrent with anything else. Once US 219 rejoins at the other side of the interchange, US 219 becomes the inventory route despite its higher number. Here, US 33 and US 219 long predate the US 48 designation so DOH probably didn't bother redoing the inventory once US 48 came along.
Quote from: LilianaUwU on December 04, 2022, 09:13:13 AM
I couldn't find the thread about wrong way concurrencies, so I'm posting it here. QC 122 has a very short wrong way concurrency with QC 224, lasting only 300 feet:
images removed
(The concurrency on Google Maps (https://maps.app.goo.gl/nKkh4tUgthem9Fps7?g_st=ic))
Here's (https://www.aaroads.com/forum/index.php?topic=22745.msg2323654#msg2323654) the thread. You may have had trouble finding it because it's in Traffic Control, not General Highway Talk.
Quote from: gonealookin on October 04, 2022, 11:48:14 PM
Quote from: Quillz on October 04, 2022, 03:28:32 AM
I've generally seen lower numbers get priority. But it's by no means a consistent rule.
Nevada follows this rule consistently, along with the Interstate > US route rule.
US 6 is mileposted all the way across the state.
US 50 is mileposted except for its concurrency with I-580 in Carson City and with US 6 east of Ely.
US 93 is mileposted except for its concurrencies with interstates in Clark County, with US 6 and 50 east of Ely and with US 50 in Ely.
Et cetera. US 95 is arguably the most significant US route in the state but it has several milepost gaps.
There is one semi-historical exception to this: The US 93/US 95 concurrency between Boulder City and downtown Las Vegas. Although there have not been too many actual mileposts present in the field as long as I can remember, what's there have always followed the US 95 mileposting instead of US 93–all the current freeway exit numbers match with US 95 county mileposts. I'm guessing the thinking was US 95 being the through route at the Spaghetti Bowl (and I believe, but cannot confirm, that US 93 mileposts were retained on the old Boulder Highway route while the freeway was gradually constructed).
When I-515 was added along the US 93/95 overlap circa 1994-95, none of the existing mileposts or exit numbers along 93/95 overlap were changed in the field–although administratively, NDOT cataloged the route as I-515. It was only recently when the southern portion of I-515 was renumbered to I-11 (after the Boulder City Bypass opened) that the corresponding exit numbers were changed to reflect interstate mileposts instead of the US 95 mileposts–although I'm not sure if that segment actually got new mileposts installed or not. With the recent AASHTO approval to extend I-11 north through Vegas to SR 157, I expect at least the rest of what is currently I-515 to be renumbered to have exit numbers match I-11 within the next year or two.