route clusters

[prenatt1166]

In McKean County, Pennsylvania -- specifically the Bradford area -- you can find PA 46 as well as PA 146, 246, 346, 446, 546 and 646 (PA 746 once existed as well).  The routes are intertwined with all (except PA 646) having at least one ending at another route in this family.

Are there any other examples in the country with this many members of a route family (Interstate, US or state) so close together ?

[mapman1071]

Long Island, Has A similar system
W to E
NY 101
NY 106/NY107 (Routes run Concurrent though Hicksville) 
NY 108
NY 110
NY 111
NY 112
(NY 113 Decertified now Suffolk CR 104)
NY 114

[DTComposer]

If I'm not mistaken, the Bay Area has the largest cluster of 3dis from a single parent in one metro area: 280, 380, 480, 580, 680, 780, 880, 980.

(New York has all 9 possible 3dis from I-90, but they're spread across the state.)

[national highway 1]

Hawaii clusters numbers by island
1x/1xx & 2x/2xx routes-Big Island
3x & 3xx routes-Maui
4x & 4xx routes-Lanai/Molokai
5x & 5xx routes-Kauai
6x-9x & 6xx-9xx Routes-Oahu
CA
23 and 27 in Ventura County
52, 54 & 56 in the San Diego Area
55 & 57 in Orange County
13 & 17; 82, 84, 85 and 87; 236, 237 & 238 in the Bay Area
74, 76, 78 and 79 in SoCal
41 and 43 in the Central Valley
94 and 98 along the Mexican border.
AZ
71, 72 & 74 in western Arizona
73, 75, 77, 78 and 79 in eastern Arizona
87 and 88 in Central Arizona
80, 82, 83, 84, 85 and 86 in southern Arizona
101, 202 & 303 in Phoenix
FL
1xx routes north of 10
2xx routes between 10 & 20
3xx routes between 20 & 40
4xx routes between 40 & 50
5xx routes between 50 & 60
6xx routes between 60 & 70
7xx routes between 70 & 80
8xx routes between 80 & 90
9xx routes south of 90

[DTComposer]

Hawaii clusters numbers by island
1x/1xx & 2x/2xx routes-Big Island
3x & 3xx routes-Maui
4x & 4xx routes-Lanai/Molokai
5x & 5xx routes-Kauai
6x-9x & 6xx-9xx Routes-Oahu
Off hand from CA
23 and 27
13 & 17; 82, 84 and 87; 236, 237 & 238 in the Bay Area

Add 22 to the L.A. area and 85 to the Bay Area.

[myosh_tino]

If I'm not mistaken, the Bay Area has the largest cluster of 3dis from a single parent in one metro area: 280, 380, 480, 580, 680, 780, 880, 980.

(New York has all 9 possible 3dis from I-90, but they're spread across the state.)

You can take 480 off your list.  The Embarcadero Freeway was torn down two decades ago.

[vdeane]

Long Island, Has A similar system
W to E
NY 101
NY 106/NY107 (Routes run Concurrent though Hicksville) 
NY 108
NY 110
NY 111
NY 112
(NY 113 Decertified now Suffolk CR 104)
NY 114

Theoretically the entire state does as that's how the highways were numbered in the 30s, though decommissionings, new routes, re-routing, and the interstate system have messed that up.

(New York has all 9 possible 3dis from I-90, but they're spread across the state.)

They also cluster too with the exception of I-990; Buffalo has I-190, I-290, and I-990, and Rochester has I-390, I-490, and I-590

[PurdueBill]

Northeastern MD has a bunch of routes in the 270s--272, 273, 274, 275, 276, 277, 279.  (278 was the connection between PA 896 and DE 896, and became unsigned MD 896.)  Neither MD 270 nor MD I-270 are nearby though.

[Takumi]

Virginia's 1933 numbering originally had a lot of clustering, because route numbers were assigned by district. This has become less prevalent over the years as routes have been decommissioned and the numbers recycled, usually in other districts. The biggest cluster I can think of is in the Roanoke/Salem area, which has 112, 115, 116, 117, and 118. It also used to have 119 (now 419) and 114 (truncated and rerouted).

111 and 114 aren't too far away in the Blacksburg area.

[Compulov]

There's a smaller set of clusters in Bucks County, PA... the x32s (PA 32, 132, 232, 332, 532). I believe all but 132 (Street Road) eventually touch the parent at some point, though 132 crosses all the rest of them. There's also the x13s (US 13, PA 213, 413), where only 413 intersects the parent. 213 only intersects 413. Oh, and I guess there's the x63s as well (PA 63, 263, 363, 463, 563, 663)... not as familiar with them since I never drive them regularly.

[PHLBOS]

There's a smaller set of clusters in Bucks County, PA... the x32s (PA 32, 132, 232, 332, 532). I believe all but 132 (Street Road) eventually touch the parent at some point, though 132 crosses all the rest of them. There's also the x13s (US 13, PA 213, 413), where only 413 intersects the parent. 213 only intersects 413. Oh, and I guess there's the x63s as well (PA 63, 263, 363, 463, 563, 663)... not as familiar with them since I never drive them regularly.

There's also x20s (US 20, 220, PA 320 & 420) although both PA routes are nowhere near US 20, 420's northern end is at 320), x52s (PA 52, 152, 252, 352, 452), where only 352 and 452 connect (452's northern terminus); x22s (US 22, 222, 322, 422, 522), x72s (PA 72, 272, 372, 472 & 772).

[Michael in Philly]

Northeastern MD has a bunch of routes in the 270s--272, 273, 274, 275, 276, 277, 279.  (278 was the connection between PA 896 and DE 896, and became unsigned MD 896.)  Neither MD 270 nor MD I-270 are nearby though.

One interesting thing there that I've always wondered about the history of:  Pennsylvania (as already mentioned) does a lot of clustering where several routes in the same area share the same last two digits:  for example, Pa. 72, 272, 372, 472, 772 all serve Lancaster County.  Maryland, as mentioned, will have a lot of series that start out the same, such as all those 270s in Cecil County.  One oddity is that Pa. 272 - which fits into that x72 series in Pennsylvania - connects to Md. 272 - which fits into that 27x series in Maryland.  Obviously the two 272s lining up is not a coincidence, but the fact that they both fit into their own states' separate numbering systems is interesting.

[Compulov]

One interesting thing there that I've always wondered about the history of:  Pennsylvania (as already mentioned) does a lot of clustering where several routes in the same area share the same last two digits:  for example, Pa. 72, 272, 372, 472, 772 all serve Lancaster County.  Maryland, as mentioned, will have a lot of series that start out the same, such as all those 270s in Cecil County.  One oddity is that Pa. 272 - which fits into that x72 series in Pennsylvania - connects to Md. 272 - which fits into that 27x series in Maryland.  Obviously the two 272s lining up is not a coincidence, but the fact that they both fit into their own states' separate numbering systems is interesting.

I used to think that it was an interesting coincidence that PA 73 and NJ 73 lined up (not realizing at the time that NJ did purposefully use the same number as bordering states for highways that connected. I figured it fit NJ's "grid" (which, iirc, just happens to be whatever order they assigned them in) since it was in the same area as NJ 70.

[Bickendan]

OR 6, 8, 10 (and WA 14!), 18; [OR] (former 208), 210, 211, 212, 213 (and 214 at a stretch), 217, 224 in the Portland Metro area

[Takumi]

Richmond has VA 2, 5, and 6, as well as US 1. It also had VA 4 from 1933-38. Most of the 400 series routes introduced in the 1980s are/were grouped in cities. Alexandria has 400-402, Norfolk has 403-407, Virginia Beach had 407-411 (all removed/decommissioned in 2001), and Richmond had 416-418 from 1982-1990.

[agentsteel53]

Washington's route numbering scheme gives rise to clustering, especially along the I-5 corridor in and just north of Seattle, and also a lot of the 26Xes are near each other.

[akotchi]

There's a smaller set of clusters in Bucks County, PA... the x32s (PA 32, 132, 232, 332, 532). I believe all but 132 (Street Road) eventually touch the parent at some point, though 132 crosses all the rest of them. There's also the x13s (US 13, PA 213, 413), where only 413 intersects the parent. 213 only intersects 413. Oh, and I guess there's the x63s as well (PA 63, 263, 363, 463, 563, 663)... not as familiar with them since I never drive them regularly.

There is also a PA 513 in that group of x13's, and it intersects its parent.  PA 313 exists, too, but I am not as familiar with that one -- it is north of the rest.  PA 113 also exists, but in Chester County.   Not sure that one reaches U.S. 13, but I know it does not get to any of the others.

PA 432 existed at one point in the Langhorne and Yardley areas as well.

That's all that come to mind right now . . .

[jemacedo9]

PA's route numbering system is very well outlined on the following site (not my site), and it explains that the clustering is intentional.  Before there were a ton of renumberings and decommissionings, there were many more clusters of route numbers.  http://www.m-plex.com/roads/numbering.html.

[Rover_0]

Utah largely uses route clustering to number its (state) routes.

You have SRs 7, 8, 9 (well, a part of 9) in the vicinity of St. George, along with SRs 12, 14, 17, and 18 that are in the southwestern part of the state.* Of course, SR-9 used to be SR-15, but still.

In the more central-southern part of the state, you have SRs 20, 21, 22, 24, 25, 28, and 29.

Around Richfield, there are SRs 118, 119, and 120 (I-70/US-89's business loop) and around Sevier County you have SRs 256, 258, 259, and 260.

Davis and Weber counties have SRs 103, 104, 105, 106, 107, 108, and 109.

State Routes 65, 66, 67, and 68 are all kinda close to Wasatch Front (though 65 and 66 are more along the Wasatch Back).

In central Utah (Millard and Sanpete counties), there's also SRs 132, 133, 136, and 137. SR-139 also is a little further east in Carbon County.

The Tremonton/Riverside areas also have SRs 81, 82, and 83.*

There's also SRs 43, 44, and 45 in the Uintah Basin and northeastern Utah.*

Who can forget SRs 268, 269, and 270 that connect I-15/80 with downtown SLC?


There's also a lot of pairs as well:

--SRs 32 and 35 near Kamas

--SRs 116 and 117 in Sanpete County

--SRs 123 and 124 in Carbon County (122 isn't far, either)

--SRs 162 and 262 near the Four Corners

--SRs 275 and 276 in San Juan County (SR-279 is in the same region, as well)

*Of course, I-15 in the southwest, I-84 near Tremonton, and US-40 in Uintah County could also fit into these patterns.

[DTComposer]

If I'm not mistaken, the Bay Area has the largest cluster of 3dis from a single parent in one metro area: 280, 380, 480, 580, 680, 780, 880, 980.

(New York has all 9 possible 3dis from I-90, but they're spread across the state.)

You can take 480 off your list.  The Embarcadero Freeway was torn down two decades ago.

Geez, can't believe I did that...and I lived there at the time!

[roadman65]

I-90 three digits are in numerical order from W to E in New York, except I-990 cause that was added later to the system.
deanj is right with his observation. On the larger scale the whole state is a fraction of I-90's total cross country routing, thus could all be considered a cluster from one point.

[Eth]

Northeastern MD has a bunch of routes in the 270s--272, 273, 274, 275, 276, 277, 279.  (278 was the connection between PA 896 and DE 896, and became unsigned MD 896.)  Neither MD 270 nor MD I-270 are nearby though.

Maryland does this throughout the state, at least for numbers over 40 and under about 300 or so.  For instance, where I used to live in central Montgomery County, almost all the route numbers were in the 107-124 range.  Further south in the county, there were a bunch of 180s and 190s.  To the north in Frederick County, most numbers were in the 80s and 90s.  Mostly 200s and 210s to the east in Prince George's County.  And so on and so on.

Georgia doesn't really have any good examples I can think of.  Unless you cheat and count 400, 401, 402, 403, and 407 all showing up in Atlanta.

[Urban Prairie Schooner]

The 1955 Louisiana route numbering system created numerous numerical clusters in the farm-to-market route sequence (basically any state route numbered 300-1241).  If you know the route number clusters well enough, you can usually correctly guess the part of the state where a route is located from the number alone.

[Quillz]

CA-38 and CA-138 are relatively close to one another and both begin (or end, depending on how you look at it) in the Big Bear Lake area.

CA-221 ends at a junction with CA-121.

[HighwayMaster]

Northeastern MD has a bunch of routes in the 270s--272, 273, 274, 275, 276, 277, 279.  (278 was the connection between PA 896 and DE 896, and became unsigned MD 896.)  Neither MD 270 nor MD I-270 are nearby though.

One interesting thing there that I've always wondered about the history of:  Pennsylvania (as already mentioned) does a lot of clustering where several routes in the same area share the same last two digits:  for example, Pa. 72, 272, 372, 472, 772 all serve Lancaster County.  Maryland, as mentioned, will have a lot of series that start out the same, such as all those 270s in Cecil County.  One oddity is that Pa. 272 - which fits into that x72 series in Pennsylvania - connects to Md. 272 - which fits into that 27x series in Maryland.  Obviously the two 272s lining up is not a coincidence, but the fact that they both fit into their own states' separate numbering systems is interesting.

PA-172 and PA-672 were also in that area. 172 is now Little Britain Road, and 672 is Fruitville Pike.

Also, on PurdueBill's comment, there is an MD-495 in Garrett County, obviously a long, long way away from I-495. (MD-495 hits I-68, confusing many)