Will the real longest state route in the US please stand up?

[Rothman]

There is no single agency over US routes, either.

AASHTO sort of is, though - states aren't supposed to change US routes without AASHTO approval, unless you're Oklahoma.

States own and maintain them.  Interstates, too, for that matter.

[US 89]

There is no single agency over US routes, either.

AASHTO sort of is, though - states aren't supposed to change US routes without AASHTO approval, unless you're Oklahoma.

States own and maintain them.  Interstates, too, for that matter.

Right but the numbering of those routes comes from FHWA and/or AASHTO with the idea that it's supposed to be a continuous route. If, say, Kansas decided to renumber its segment of I-70 as something else, neighboring states would fight them on that. Nothing is stopping Kansas from renumbering its portion of OK/KS/NE 99.

[MNHighwayMan]

This is why I personally do not consider ID/MT/ND/MN 200 to be a single route.  For instance, a state in the middle (say North Dakota) could (in theory) unilaterally change the number of ND 200 to something else without input from any of the other states.

The agreement on numbering clearly means that the DOTs in question consider it to be a single route, or else, why would they bother? Not to mention the fact that while they could change the number, why would they? Especially in the case of MSR 200, in which numbers were changed to make it consistent.

P.S. I have established a list of state routes that traverse three or more states here.

[thspfc]

Can we stop with the "ID/MT/ND/MN-200" thing? If it were truly meant to be one big route, it would have a US shield on it. We're making this way harder than it needs to be.

[Max Rockatansky]

Can we stop with the "ID/MT/ND/MN-200" thing? If it were truly meant to be one big route, it would have a US shield on it. We're making this way harder than it needs to be.

How is that possibly detracting from the conversation at hand?   The argument for it being considered the longest state Route (albeit multistate) is very pervasive. 

[kphoger]

It is, however, clearly not what the OP was looking for.

[thspfc]

Can we stop with the "ID/MT/ND/MN-200" thing? If it were truly meant to be one big route, it would have a US shield on it. We're making this way harder than it needs to be.

How is that possibly detracting from the conversation at hand?   The argument for it being considered the longest state Route (albeit multistate) is very pervasive.

Even if you only take the Montana portion it's the longest anyway, so it doesn't matter.

[kphoger]

Can we stop with the "ID/MT/ND/MN-200" thing? If it were truly meant to be one big route, it would have a US shield on it. We're making this way harder than it needs to be.

How is that possibly detracting from the conversation at hand?   The argument for it being considered the longest state Route (albeit multistate) is very pervasive.

Even if you only take the Montana portion it's the longest anyway, so it doesn't matter.

Did you even read the OP?  He is specifically disputing that fact.  That's the whole point of the thread.

[CNGL-Leudimin]

I consider the so-called multi-state routes to be a chain of as many state routes as states are implied that just happen to have the same number all the way through. For example I consider the ID/MT/ND/MN 200 to be a chain of four state routes, of which I thought MT 200 was the longest state route in the USA until Duke87 pointed out CA 1 is actually longer, but doesn't appear so from the logs.

[NE2]

That said, the longest of these concurrencies - along US-101 between Sea Cliff and Las Cruces - does not have (I'm pretty sure) a single CA-1 shield along the entire 55 miles. The LA/OC section and the Central Coast section are really two distinct routes.

http://www.google.com/maps/@34.3449859,-119.4184921,3a,49y,357.22h,91.4t/data=!3m6!1e1!3m4!1s0cgtq-EacT9CVjIV59F_Kg!2e0!7i16384!8i8192

[Scott5114]

At issue is CA 1, whose official length is given as only 655.845 miles... however because CalTrans is CalTrans, this figure omits the length of CA 1's multiple concurrencies with US 101, and I suspect it may also omit the sections of route which have been relinquished from state maintenance. Regardless of the details it is clear this official number is lowballed by some substantial margin.

I'm sure your figure is closer to the truth, as I have noticed similar problems with the lengths of other routes as listed on Wikipedia.  The problem is Wiki requires every statement to be sourced, which on the one hand I do understand, but then again it's laughable to pretend every bit of DOT information is reliable.  Wiki frowns on "original research", but sometimes original research (as you have done) is the only way to get an accurate answer.

The argument following this post about whether the various routes 200 should be considered one long route is a wonderful illustration of why Wikipedia doesn't allow original research.

(P.S., don't call it "wiki", that's just the type of software it runs. It's like calling this website Forum.)

[hbelkins]

Going back to the OP, is there any official documentation from the states?

In theory, KY 80 is likely the longest state-numbered highway. And once official measurements are consulted, it's likely that would be the case as well. But Kentucky no longer officially recognizes concurrencies, even though they may be signed. Even official state maps that once designated concurrencies no longer show them. Only the highest-system route is officially recognized. That means that for the lengthy US 68/KY 80 concurrency across southern Kentucky from Kentucky Lake to Metcalfe County, KY 80 doesn't exist. The mileage is all for US 68 -- except for that stretch north of Bowling Green where the two are concurrent with US 31W, and in that case US 31W is dominant because it's the same route classification as US 68 but carries a lower number. Ditto the short concurrency with US 25 in London and longer ones with US 421, US 23, and US 460.

Other places where this occurs are segments of concurrency with KY 61, KY 76 and KY 15. The official mileage and mileposting is for those lower-numbered routes.

It would be possible to compute the total signed length of KY 80 from the beginning of state maintenance near the old ferry at the Mississippi River at Columbus to the Virginia state line near Breaks, but that would be an unofficial figure.

[vdeane]

This is why I personally do not consider ID/MT/ND/MN 200 to be a single route.  For instance, a state in the middle (say North Dakota) could (in theory) unilaterally change the number of ND 200 to something else without input from any of the other states.

The agreement on numbering clearly means that the DOTs in question consider it to be a single route, or else, why would they bother? Not to mention the fact that while they could change the number, why would they? Especially in the case of MSR 200, in which numbers were changed to make it consistent.

P.S. I have established a list of state routes that traverse three or more states here.

Many places number their routes on state borders to match neighboring states as a matter of course.  On the NY/VT border, only two routes change number - NY 7/VT 9, because US 9 intersects NY 7, and US 7 intersects VT 9, making renumbering each to match the other impossible; and NY 185/VT 17, because NY 185 was only given a signed number in the last decade.  There are also former examples on the US/Canadian border, including BC 99, which was numbered to match US 99, but now changes to I-5 (BC 97, meanwhile, actually was explicitly to be part of a corridor with US 97, but the Yukon didn't cooperate, so US 97 didn't make it to Alaska).

[DTComposer]

That said, the longest of these concurrencies - along US-101 between Sea Cliff and Las Cruces - does not have (I'm pretty sure) a single CA-1 shield along the entire 55 miles. The LA/OC section and the Central Coast section are really two distinct routes.

http://www.google.com/maps/@34.3449859,-119.4184921,3a,49y,357.22h,91.4t/data=!3m6!1e1!3m4!1s0cgtq-EacT9CVjIV59F_Kg!2e0!7i16384!8i8192

That's why I said Sea Cliff - this is specifically the sign I was thinking of. From this point north/west, there's not another CA-1 sign until Las Cruces.

[NE2]

In theory, KY 80 is likely the longest state-numbered highway.

In what world is 486 greater than 706?

[ftballfan]

In theory, KY 80 is likely the longest state-numbered highway.

In what world is 486 greater than 706?

I think he was meaning the longest in Kentucky

[renegade]

In what Trumpo dystopia is 486 greater than 706?

This should win post of the day!

[thspfc]

In what Trumpo dystopia is 486 greater than 706?

Kentucky, apparently.

[hbelkins]

In theory, KY 80 is likely the longest state-numbered highway.

In what world is 486 greater than 706?

Context is your friend. I was using the Kentucky example to speculate if this might not be the case with other states. Or, even a factor in calculating Kentucky's longest highway, given that much of what is signed as KY 80 does not officially exist. (As noted, it's US 68, US 31E, US 421, etc.)

[sparker]

From a touring standpoint I get the idea of signing as many of the coast side highways as possible as CA-1, though - they should also pick up the historic US-101 routing in San Diego County.

According to my ex-Caltrans employee cousin who had just started working there while they were in the process of coming up with the '64 renumbering, the original idea for PCH in SoCal was to reinstate CA 3 on that segment of then-Alternate US 101.  But several jurisdictions along that route, including both L.A. and Ventura counties, pushed for CA 1 for just the reasons cited above -- as an aid to tourism, making the coastal route west of US 101 a single easy-to-remember number.   That view prevailed, and CA 3 ended up as a relatively obscure mountain highway in the northern reaches of the state. 

Since Caltrans isn't in the least interested in assuming maintenance of additional urban/suburban surface mileage, the chances of a CA 1 in northern San Diego County are effectively nil. 

[Duke87]

Going back to the OP, is there any official documentation from the states?

As with KY 80, CA 1 does not officially exist where concurrent with US 101. Nor does it officially exist on segments that are signed but locally maintained.

This is why only an unofficial figure for the end-to-end length of the route is possible - the official mileage figure from CalTrans is only the total state-maintained mileage that is inventoried as CA 1. You could add the concurrencies back in manually using official numbers by consulting the postmiles for US 101, but for the locally maintained segments... CalTrans just doesn't measure the length of those.


Kentucky and California are not the only two states where there are issues like this - offhand, I know Utah also only counts concurrency mileage for one route, the other route will have its mile markers freeze where the concurrency begins and then resume where they left off after it ends.

For the purpose of this specific question, however, most states are irrelevant. California, Montana, Texas, Alaska, Idaho, and Florida are the only states whose geography could realistically contain a state route over 700 miles long. It is easily demonstratable that Alaska, Idaho, and Florida have none that are anywhere near that long.

Texas, meanwhile, has the same issue of concurrencies not being counted in official mileage, but nonetheless a perusal of TravelMapping data does not identify any likely candidates. The longest state highway in Texas is... well it appears to be a close call between TX 6 and TX 16, both are ~560 miles give or take a few. The most recent minute order for TX 6 actually states within its text "total approximate distance of 560.0 miles", so that jives. You also wouldn't expect any large discrepancies between TM mileage and actual mileage with these roads like is seen with CA 1, since Texas' topography does not produce any routes that have loads of switchbacks and other twists over the course of hundreds of miles.

Montana measures mileage using an internal inventorying system that usually does not match signed numbers. MT 200 consists of pieces of P-6, N-5, I-90, N-24, N-3, I-15, I-315, N-60, N-57, P-51, and N-20. So the mileage listed on Wikipedia is computed from official data rather than explicitly listed within it, but it includes all concurrencies and thus is accurate to what's in the field. So we can be confident MT 200 isn't secretly longer than Wikipedia says it us, unlike CA 1.

[Duke87]

That said, the longest of these concurrencies - along US-101 between Sea Cliff and Las Cruces - does not have (I'm pretty sure) a single CA-1 shield along the entire 55 miles. The LA/OC section and the Central Coast section are really two distinct routes.

Now this... is an interesting point.

There is the one sign NE2 linked to asserting that CA 1 continues north along US 101 from Sea Cliff, but that may be the only signed indication of such that there is. I checked in Las Cruces and signs at the split there are just for US 101 north and south, with no mention of CA 1 continuing south from there. There was even an end sign in 2015! Though imagery from 2017 on that ramp shows it gone.

So, okay, it looks like one could make a reasonable argument that there are actually two discontinuous segments of CA 1. If this is assumed to be the case, then the longer of the two segments is well under 600 miles long, leaving MT 200 head and shoulders above anything else. Even if the mileage from the two segments is combined, it's still going to be under 700 miles and thus less than MT 200.


This potentially reduces this question to not having a single objectively correct answer!

[usends]

Texas, meanwhile, has the same issue of concurrencies not being counted in official mileage, but nonetheless a perusal of TravelMapping data does not identify any likely candidates. The longest state highway in Texas is... well it appears to be a close call between TX 6 and TX 16, both are ~560 miles give or take a few. The most recent minute order for TX 6 actually states within its text "total approximate distance of 560.0 miles", so that jives.

I measured both of those manually when researching this article, and came up with:
TX 16: 568 mi.
TX 6: 551 mi.

...and why did I have to measure them myself?  Because WP's figure for TX 16 is 26 miles short, and their figure for TX 6 is 75 miles short.  But hey, their figures are sourced to TXDoT, so everyone can carry on pretending they're correct.

[vdeane]

For the purpose of this specific question, however, most states are irrelevant. California, Montana, Texas, Alaska, Idaho, and Florida are the only states whose geography could realistically contain a state route over 700 miles long. It is easily demonstratable that Alaska, Idaho, and Florida have none that are anywhere near that long.

The temptation to lobby NY to create a numbered state route "beltway" around the state following the NY 17, I-87, US 9/NY 9A, NY 27, NY 114, NY 25/NY 25A, I-95, NY 22, US 11, NY 37, NY 12, NY 12E, NY 3, NY 104, NY 384, NY 5, and NY 76 corridors just to make this statement false is strong.  Such a route would be over 1100 miles long.

[Scott5114]

Texas, meanwhile, has the same issue of concurrencies not being counted in official mileage, but nonetheless a perusal of TravelMapping data does not identify any likely candidates. The longest state highway in Texas is... well it appears to be a close call between TX 6 and TX 16, both are ~560 miles give or take a few. The most recent minute order for TX 6 actually states within its text "total approximate distance of 560.0 miles", so that jives.

I measured both of those manually when researching this article, and came up with:
TX 16: 568 mi.
TX 6: 551 mi.

...and why did I have to measure them myself?  Because WP's figure for TX 16 is 26 miles short, and their figure for TX 6 is 75 miles short.  But hey, their figures are sourced to TXDoT, so everyone can carry on pretending they're correct.

Coming at it from the Wikipedian perspective: If TxDOT says that 75 miles is not part of SH 6, and TxDOT/the Transportation Commission is the authority responsible for determining what is and is not a Texas state highway, doesn't that make that 75 miles factually not part of SH 6?