numbering question

[sernum]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

[oscar]

^ Because those states' DOTs maintain lots of minor routes that in other states would be county or municipal routes.

Virginia, North Carolina, and Pennsylvania have state-maintained secondary route systems. Virginia's secondary route numbers go into five digits, and the other states' numbers go into four digits. However, the secondary routes are signed differently from primary routes.

Hawaii has a few routes, signed like all the others, with four-digit numbers (highest is 8930). However, the state maintains only a few hundred routes, so unlike Kentucky and Louisiana it isn't a route number shortage that explains Hawaii's four-digit route numbers.

[formulanone]

Texas also has numerous Farm-to-Market and Ranch-to-Market Roads up to the 3500s.

Some scattered counties also post four-digit routes, but with varying numbering patterns.

[Scott5114]

Of course, the reason the FM/RM numbers get so high is because Texas is a huge state, so it would be impossible to maintain a statewide route system with only three digits without duplication.

North and South Dakota and New Mexico each have a few four-digit route numbers chosen for commemorative purposes: ND/SD 1804 and 1806 (which flank the Missouri River and are numbered after the dates of the Lewis and Clark expeditions), NM 1113 (a former CR 113 turned state road; presumably NM 113 was already in use), former NM 2001 (serving the New Mexico Space History Museum in Alamogordo), NM 6563 (serving the solar observatory near Cloudcroft, which uses a wavelength with frequency 6563 Ã... in their work). New Mexico also has a NM 5001 for no good reason.

[Max Rockatansky]

Florida has a couple like 9336.  That came to be because much of the 9XX grid had already been used up when they decided to renumber FL 27.

[LilianaUwU]

Of course, the reason the FM/RM numbers get so high is because Texas is a huge state, so it would be impossible to maintain a statewide route system with only three digits without duplication.

And even then, they keep duplicating numbers between their systems, so imagine if they only had three numbers to work with.

[oscar]

New Mexico also has a NM 5001 for no good reason.

US 64 was rerouted around downtown Farmington, over NM 5001, with the old route becoming business US 64. 5001 is now unsigned, if it ever was signed.

Puerto Rico has a few dozen four-digit routes up to 9991, in the third tier of the Commonwealth's highway system (the tiers are signed differently).

[SkyPesos]

Same reason why Missouri and Wisconsin are the only two states with a statewide system of signed letter routes.

[Dirt Roads]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

[sernum]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

[formulanone]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

They use "fractional" routes, though they're just the numbered sequence of a route that branched off its parent route. For example, this is the twentieth route from a county line off of US 60:



It's not the 60/20th route.

[Max Rockatansky]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

They use "fractional" routes, though they're just the numbered sequence of a route that branched off its parent route. For example, this is the twentieth route from a county line from US 60:



It's not the 60/20th route.

I always thought it was odd that they just didn't designate the Spurs with letters like the National Forest Service does.  Example; 60/20 could be 60T.

[Mapmikey]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

They use "fractional" routes, though they're just the numbered sequence of a route that branched off its parent route. For example, this is the twentieth route from a county line from US 60:



It's not the 60/20th route.

I always thought it was odd that they just didn't designate the Spurs with letters like the National Forest Service does.  Example; 60/20 could be 60T.

This would be impractical as some spurs go way beyond 26 of them and in fact some counties have so many they change the numerator to 2xx to keep from using >100 in the denominator.

South Carolina also has posted state-maintained secondary numbers that exceed 1000 in most counties.

[Max Rockatansky]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

They use "fractional" routes, though they're just the numbered sequence of a route that branched off its parent route. For example, this is the twentieth route from a county line from US 60:



It's not the 60/20th route.

I always thought it was odd that they just didn't designate the Spurs with letters like the National Forest Service does.  Example; 60/20 could be 60T.

This would be impractical as some spurs go way beyond 26 of them and in fact some counties have so many they change the numerator to 2xx to keep from using >100 in the denominator

It would be easy, if it does go to the 27th spur do something like "60AA."  

[Dirt Roads]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

If only we could do the math...

[Mapmikey]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

On the other hand, you could've asked why West Virginia is the only state with route numbers that go into the thousandths.

decimals???

They use "fractional" routes, though they're just the numbered sequence of a route that branched off its parent route. For example, this is the twentieth route from a county line from US 60:



It's not the 60/20th route.

I always thought it was odd that they just didn't designate the Spurs with letters like the National Forest Service does.  Example; 60/20 could be 60T.

This would be impractical as some spurs go way beyond 26 of them and in fact some counties have so many they change the numerator to 2xx to keep from using >100 in the denominator

It would be easy, if it does go to the 27th spur do something like "60AA."  

Right...but the 90th spur requires 4 letters for a 6 or 7 character designation.

[hotdogPi]

Right...but the 90th spur requires 4 letters for a 6 or 7 character designation.

No, it would be 60CL.



How about 60😶, 60💾, and 60🛵?

[Scott5114]

Assuming you use all 26 letters, two letters gives you 26×26=676 additional possible combinations. If you go to three letters you get 26×26×26=17,576 more combinations.

Obviously, not using certain letters because of potential readability issues reduces the number of combinations. Missouri doesn't use G, I, L, Q, S, or X, meaning there are theoretically 420 letter routes available to each county (20 single-letter routes + 20×20 = 400 two-letter routes). Functionally, it's rare that a county uses all 20 of the single-letter routes, the 20 double-letter routes, and the 19 remaining A* routes.

How about 60😶, 60💾, and 60🛵?

Unicode currently defines 144,697 characters, so if you allow two of any Unicode character to be used, you could have 20,937,221,809 possible spurs. (Functionally some of these would be useless, though, since they're things like non-breaking spaces, various forms of punctuation and diacritics, Cyrillic and Greek characters that look more or less like Latin ones, etc.)

[Dirt Roads]

Curiosities in the West Virginia "fractional" route numbering:

The highest denominator that I can find is 19/96 in Little Birch (Braxton County).

The "biggest" number (most digits with highest numerator) that I can find is CR-119/95 in Anchor (Boone County).

Some counties have a prevalence of "fractionals" with single digits in both the numerator and denominator.  The is certainly the case in northern Braxton County.  This only occurs when the single digit county routes are more important than the two-digit county routes.

Some "fractional" route numbers cross back-and-forth across county lines.  In general, if the route returns to the originating county the number stays consistent.  WVDOH grays out the route shields on the county maps when the routes are not in the originating county.

Multiplexes of US routes and state routes (both current and former) can create some interesting "fractionals".  There are a bunch of 19/X, 21/X, 16/X and 61/X routes interspersed in Fayette County between Mount Hope and Oak Hill.

Sometimes the county routes and their "fractionals" are clustered together.  An interesting twist is the cluster of 21 (21/X), 22 (22/X), 24 (24/X), 28 (28/X) and 29 (29/X) in northern Kanawha County.  Of course, LSR-21 is the former US-21.  (As best as I can tell, the designation LSR means "long secondary route" where the designation crosses multiple county lines).

Mapmikey pointed out that sometimes WVDOH increases the numerator in order to reduce the number of branches off a major route such as US-60.  There are a bunch of 160/X "fractional" routes in West Huntington, Pea Ridge and Barboursville (Cabell County).  Fun fact:  When this happens along US-119 in Kanawha County, the overflow "fractionals" are numbered 219/X (which are nowhere near US-219).  When this occurs along US-19 in Raleigh County, the overflow "fractionals" are numbered 119/X (which are closer to US-119 but not quite). 

Occasionally, this happens off of state routes.  There are a bunch of 103/X routes in Raleigh County along WV-3.

Curiously, there are lots of "fractional" routes numbered after the Interstate routes.  There are so many 64/X routes in Cabell County that the series extends to 164/X.  CR-64/99 is located in the East Pea Ridge section.  Some of the 64/X routes are actually south of US-60 (which is south of I-64 in the area west of the 29th Street East exit (Exit 15).  There are also some 81/X routes in Berkeley County.

There are some new numerators interleaved with old numerators.  For instance, there is a prevalence of 17/X interspersed with 119/X in southern Boone County.  Interestingly, WVDOH shows the old numerators (in this case, 119/X) route shields grayed out on the county maps.  WV-17 replaced US-119 after the latter was relocated onto Corridor G.

West Virginia also has "fractionals" for the HARP numbering (Home Access Road Program).  These all seem to be in lower 900s for the numerator, and the highest denominator was 902/99 in Cherry Run (Berkeley County).  Interestingly, there are no branch routes for WV-901 in the county road "fractionals".

Since I was unable to find any consolidation of route listings, I got all of this from county maps.  It is likely that this information is incomplete and incorrect.

[hbelkins]

^^^

There are some 252 numerators in Mingo County. In fact, I think the entire old routing of US 52 (where the new construction runs along the ridgetop between WV 65 and the new WV 44 connector) has a 252-numerator number.

[skluth]

Assuming you use all 26 letters, two letters gives you 26×26=676 additional possible combinations. If you go to three letters you get 26×26×26=17,576 more combinations.

Obviously, not using certain letters because of potential readability issues reduces the number of combinations. Missouri doesn't use G, I, L, Q, S, or X, meaning there are theoretically 420 letter routes available to each county (20 single-letter routes + 20×20 = 400 two-letter routes). Functionally, it's rare that a county uses all 20 of the single-letter routes, the 20 double-letter routes, and the 19 remaining A* routes.

There are some double-letter combos that need to be avoided for other reasons. I doubt many businesses would want to be located on CTH FU.

[JayhawkCO]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

They're not.  North Dakota has two -- ND1804 and ND1806.

[74/171FAN]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

They're not.  North Dakota has two -- ND1804 and ND1806.

Fairfax County, VA, has secondary route numbers in the 10000s.

[JayhawkCO]

why are Kentucky and Louisiana the only two states with routes numbers that go into the thousands?

They're not.  North Dakota has two -- ND1804 and ND1806.

Fairfax County, VA, has secondary route numbers in the 10000s.

This I know, but North Dakota has two that are primary.

[Dirt Roads]

^^^
There are some 252 numerators in Mingo County. In fact, I think the entire old routing of US 52 (where the new construction runs along the ridgetop between WV 65 and the new WV 44 connector) has a 252-numerator number.

That's interesting, because there are no 152/X routes in Mingo County.  I suspect that is related to WV-152 in Wayne County next door.  It looks like Wayne County consistently has 152/X routes branching off of WV-152 (old US-52), and 252/X routes branching off of the Tolsia Highway (new US-52).