Numbers derived from previous route numberings

[ilpt4u]

IL 54 is part of former US 54, after US 54 was truncated in IL

[bulldog1979]

In Michigan:

• the second M-10 was part of US 10;
• the current M-25 was part of US 25;
• the current M-27 was part of US 27;
• M-99 was once M-9;
• the current M-120 was part of M-20;
• M-121 was part of M-21;
• M-183 was part of CR 483;
• M-227 was once part of US 27;
• The former M-331 was once US 131;
• M-343 was a part of M-43; and
• M-553 was CR 553.

I'll leave it to others to decide if M-38's number was derived from M-35 or not.

[TheHighwayMan3561]

Continuing Minnesota then,

-MN 61 was once part of US 61, made discontinuousm by I-35.
-MN 210 and MN 371 are both decommissioned US routes, although I think MN 210 existed alongside US 210 west of Staples. MN 210 also goes further east than its counterpart.
-MN 110 (former) and MN 120 are/were extant remaining sections of the old MN 100 beltway (generally replaced by I-494 and I-694), just adding multiples of 10.
-MN 62 was the state number assigned to Hennepin County Road 62 when the state took it over. An unrelated MN 62 already existed, and still does.
-The old route of US 12 through Maple Plain is now Hennepin County 112.

[SectorZ]

MA 38 was MA 3B. Guess they just picked the closest looking number...

[Mr. Matté]

The only Jersey answer that truly meets the OP's intent is current Route 109 being former US 9. The next closest example is NJDOT playing Two Away when renumbering the former alignment of US 322 to the Chester, PA ferry to Route 324.

[adt1982]

IL 250 was US 50.  IL 251 and IL 351 were US 51.  IL 316 (now gone) was IL 16.  IL 203 was IL 3.

[thspfc]

WI-16, at large, was US-16. WI-110 was US-110. That's all I can think of off the top of my head.

[sparker]

CA 197 (former LRN 81) is a connector for traffic to & from northward US 101 to US 199; using the closest odd/unused number to 199 was likely not coincidental.  Incidentally, under the old system LRN 1 (the Redwood Highway, mostly US 101 north of the Golden Gate Bridge) turned inland with US 199; US 101 from US 199 to the Oregon state line was LRN 71.

[dlsterner]

In Maryland, MD 450 is the number used by an older routing of US 50.

In Pennsylvania, PA 272 (south of Lancaster, to Wakefield) was formerly a southern extension of PA 72.

I'm sure this happens a lot when a former alignment of a US highway "xx" gets replaced by a state highway "nxx".

[TheHighwayMan3561]

WI-16, at large, was US-16. WI-110 was US-110. That's all I can think of off the top of my head.

WIS 213 (other than the extension to the IL line) is a surviving section of WIS 13 after that was truncated to the Dells.

[kurumi]

Most CT state routes above 220 "rhyme" (have the same number modulo 100) of an earlier unsigned state road. For example, CT 305 was SR 905; CT 263 was SR 863. (There are a few oddballs like 286 and 287 where I haven't found the origin yet.)

Some signed route history comes in to play as well: CT 289 was part of 89; CT 209 was part of 109; CT 272, CT 372 and (older) SR 572 were parts of 72.

DIGRESSION ALERT:

I spent most of my childhood in Ellington, CT, so I am very aware of the L-shaped CT-286.

You may now return back to topic.

Photo of the Conn Hwy Dept Route Numbering Committee finishing up with CT 286:

[Bruce]

In Washington:

When US 12 was extended to the Pacific Ocean in 1967, it took over the route of State Route 14 across White Pass. The existing State Route 12 ran on the north bank of the Columbia River and was renumbered to SR 14. Thus, the auxiliary routes were switched over. SR 120 became SR 140, SR 122 became SR 142, and old SR 143 became SR 123.

Luckily a few of the existing routes in the 12X range lined up with the routing of US 12 near Walla Walla.

When US 830 was decommissioned in 1968, it was replaced with SR 4 and the auxiliary routes followed suit (831 to 833 became 431 to 433).

[english si]

In Poland the new DW333 seems to have come from it's old number DK3 (though it could just be that that number is spare). Similarly, in England the A333 is part of the old A3 (that one is certainly 'its a free number').

The UK has quite a few of them:

A3400 is old A34
B4100 is old A41 (both of them)
B430 is old A43
A4421 is old A421
A4260 is old A426
(these are all one large renumbering blitz when the M40 opened)


A1000 is old A1
A1010 is old A10
A2020 was old A20 (now back as A20)
B384 is old A38 (was B38, with the Government telling Birmingham city council that as the road is in the 4-zone, it needs a 4, so they put it at the end rather than the beginning - should be B438)
B2259 is old B259
A4361 is old A361

----

You also have the French stuff where they might add 600, 900, 1000, 2000 (depending on the authority doing it) or whatever when downgrading/bypassing, etc - N2043 (old A43), N2350 (old A350), a huge number of D roads that were N roads, etc. For example, these bits of N2 through villages that were bypassed became N2002 (add 2000) before becoming D2602 and D602 (with 600 added to 2002 and 2 respectively)

[D-Dey65]

There are probably a bunch of these in Florida, but one that I know of for fact is Hernando County Road 550 being former Florida State Road 50. And plenty of people here know this too, but I had to bring it up before someone else did.

[jemacedo9]

In Pennsylvania, PA 272 (south of Lancaster, to Wakefield) was formerly a southern extension of PA 72.

Also in PA, when the PA 60 freeway became I-376, the southern non-freeway portion remained PA 60, but the northern portion, north of I-80, became PA 760.

That's the only signed change that I can think of off the top of my head.

[roadman65]

PA 512 was derived from PA 12 that was its parent at the time.  PA 191 was old PA 12.  Today's PA 12 was commissioned in the late 80s or early 90s.

[renegade]

Also in Michigan, M-125 became part of the old US-25 alignment in 1974.

[NWI_Irish96]

Before US 136 was commissioned in Indiana, it was IN 34.  IN 134, 234, and the now defunct 334 were all child routes of IN 34.

Before US 35 was commissioned in Indiana, part of it was IN 21, and IN 121 was a child route.

[cwf1701]

In Michigan:

• the second M-10 was part of US 10;

The 2nd M-10 was in Flint in the 1930 and the 3rd M-10 (since 1987) is the current one. both M-10 was put on a former aliment of US-10. The Flint M-10 was then renumbered to BUS-US-10 in 1941.

[mapman1071]

I-510 In Phoenix became AZ 51

[The High Plains Traveler]

My thread a few days ago on the 1934 California highway numbering system made me think of the times that a later route number for a road is a direct descendant of the previous one in some form, as this has occurred occasionally in this state.  Curious of examples elsewhere!

There's former LRNs too, like CA 58.

CA-127 was part of the original LRN 127. It's the only pre-1964 road I can find where the LRN and State Sign Route line up even in part. LRN 189, which did not have a pre-1964 SSR number, is CA-189.

[DandyDan]

Semi-related:  about two dozen Minnesota state route numbers are loosely based on their original Constitutional Route.  These Constitutional Routes retained their original route number at least in part during the massive 1933 renumbering and route system expansion.

There are also the cases of MN 135 and MN 194, which were originally MN 35 and MN 94 respectively and renumbered when the Interstates came around.  I believe the reason why there isn't an I-294 is because MN 294 was already being used and MnDOT's predecessor did not feel like renumbering it.

The old MN 190 can also be lumped in with that group.

[DandyDan]

For Nebraska, the former NE 38 was renumbered from US 38, which had followed a large part of its route. Also, NE 128 was previously NE 129, before I-129 came to Nebraska.

As for Iowa, I don't think any current state highway designation exists which is a pure derivative of a previous designation, but unsigned IA 906 and IA 930 used to be US 6 and US 30, respectively. County road D20 in the Fort Dodge area, F90 going west from Des Moines, H34 going east and west from Red Oak and X99 going north from Burlington all got the numeric portion of their name from the previous highway designation.

[roadfro]

There's one instance I can think of in Nevada... SR 38 became SR 318 in the 1976 renumbering. Possibly a bit of a stretch since the new number fits with the county-cluster numbering in Lincoln County–but when you look at the locations of SR 317 through 322 in Lincoln County and also factor that a significant chunk of SR 318 is also in Nye County (which could have put the number in the 370s), I think NDOT chose 318 as an homage to old 38.

[TEG24601]

In Indiana, along the new US-24 expressway/Hoosier Heartland Highway, former routings of US-24 which still service towns or have plenty of traffic are designated x24.  I believe the same is true along US-31.