What is the highest numbered Highway in your State?

[froggie]

It does now.  As for Mississippi state highways, several of the 7xx/8xx/9xx routes are signed.  I couldn't tell you the highest one that's signed, but the highest one in existence is MS 992 near Picayune.

[agentsteel53]

Doesn't US 425 extend into Mississippi?

I think it does, ending at 61.

[golden eagle]

When did that happen and how down into Mississippi does US 425 go? Perhaps could you be confusing that with US 278? It's co-signed with 61 from Clarksdale to Leland and then from Leland westward into Arkansas on US 82.

I guess I need to find an updated Mississippi state map or hit the road more often.

[agentsteel53]

as of early January 2010, 425 multiplexes with 84 starting in Louisiana, crosses the river at Natchez, and the last 425 sign is a gantry that says 425/84 (reassurance) and then TO 98, TO 61.  There is no END 425, but at the 61 junction, there are no 425 shields.

[agentsteel53]

looks like USEnds has a photo from about the same time I was there of the last 425 southbound shield.

http://www.usends.com/Focus/Natchez/index.html

[froggie]

In a nutshell, what used to be US 65 in Mississippi got replaced by US 425.

[agentsteel53]

In a nutshell, what used to be US 65 in Mississippi got replaced by US 425.

wasn't 65 longer at one point, multiplexing with 61 all the way to New Orleans?

[froggie]

Yes it was, then later truncated to Natchez, though internal MDOT docs suggested a hidden duplex down to the LA/MS line south of Woodville all the way to the recent truncation and US 425 extension.

[florida]

I think the highest numbered state highway in Florida is SR-9336 down in Florida City.

It is. And more, to continue:

Unsigned State Route: 913
Interstate: 595 [so far...]
US Route: 441
Suffixed State Route (alphabetically & signed): 30-E
Suffixed State Route (unsigned): 618A
Highest County Route (signed): Volusia CR 4162
Highest County Route (unsigned): Brevard CR 5054 [Although, there are/were secret routes in Miami-Dade and the highest was 9339, and there was one CR 7865 in Daytona Beach Shores along with a CR 8388 on Marco Island]

[sandiaman]

  In   New  Mexico:    Highest  numbered  state  route:  easily, NM 6563 in Otero  County
                             Highest  numbered  US  Route  US  550 in NW  portion of the state
                             Highest  interstate  route:  I-40

[dave19]

WV
SR 972, Mineral County
US 522
I-470

[Hot Rod Hootenanny]

In a nutshell, what used to be US 65 in Mississippi got replaced by US 425.

wasn't 65 longer at one point, multiplexing with 61 all the way to New Orleans?

At one time US 65, 51, 11 and 61 all ended at the intersection of Broad and Tulane in New Orleans.

[yakra]

New Hampshire:
Interstate: I-393
US Highway: US 302
State Highway: NH 236

Don't forget NH286!

Maine:
Interstate: I-495 (the current unsigned portion)
US Highway: US 302
State Highway: ME 238

...And I-395 is the highest signed interstate.

[Dougtone]

New York:
Interstate: I-990
US Route: US 219 or US 220 (depending on where you put the end of US 220; on Upstate NY Roads it's main st (old NY 17) in Waverly)
State Touring Route: NY 890
State Reference Route: NY 992P
Decomissioned/unsigned: depends on what you count; I-878 fits the bill, as do NY 790 and NY 781 (both are reserved but not used)
I think Chautauqua county has an unsigned CR 8139, but I'm not sure what to make of it.

From what I've seen from NYSDOT route logs and from a few people questioning why I would have a US 220 ends page for the long-since-updated NY Ends site, US 220 doesn't technically enter New York.  Yes, US 220 is signed into New York State, but I'm guessing that the official end is at NY 17 (which at that point is in Pennsylvania).  US 220 (also US 309) used to enter New York State from Pennsylvania Ave., ending at what was NY 17 at the time, clearly within Waverly, NY.

There is also a signed Saratoga CR 1345 in Mechanicville.

[hm insulators]

Former: (unbuilt) I-710 Tucson

was 710 ever signed?  410 was, so that may have been the highest-ever signed interstate route in AZ.

No, 710 was cancelled by NIMBYs in Tucson.

Sounds like the 710 in South Pasadena, California.

[Ian]

New Hampshire:
Interstate: I-393
US Highway: US 302
State Highway: NH 236

Don't forget NH286!

Maine:
Interstate: I-495 (the current unsigned portion)
US Highway: US 302
State Highway: ME 238

...And I-395 is the highest signed interstate.

D'oh! I made a typo in the NH 236-286 one and meant to put I-395 in there.

[Mapmikey]

The highest SR in North Carolina is in Mecklenburg County, SR 6023.  Wake County has made it to 5813.

The NCDOT website has a secondary route lookup feature that is useful for researching this question...

For South Carolina:
Highest Interstate: I-585
Highest US Route: US 701
Highest State route: SC 917 (historically SC 946)
Highest secondary route: don't know but I know a couple counties must be approaching 3000 by now

Mapmikey

[mhallack]

In Maine: I-395, about 4 miles long going from Bangor to Brewer
US Route:302
State highway, don't know, but probably in the high 200's. I must brush up on the info

[Revive 755]

For Missouri:
Highest signed state route:  MO 765
Highest unsigned state route:  MO 799 (MLK Bridge)
Highest interstate:  I-670
What could have been the highest interstate:  I-870 (for MO 370, see kurumi's page; the P-D traffic column has also seemed to have backed this)
Highest US Route:  US 412
Former highest US Route:  US 460.

For Iowa (borrowing from the Iowa highways page):
Highest signed:  IA 415
Highest unsigned:  IA 946
Former highest:  IA 988
Highest interstate:  I-680
Highest US Route:  US 275

For Nebraska:
Former highest signed:  NE 2183
http://www.dm.net/~chris-g/ne300up.html

[Revive 755]

Illinois;
Highest unconstructed: I-494 (was for the Crosstown Expy)
Highest unsigned: Several 900 series routes on formerly signed state routes still maintained by IDOT

Highest unconstructed could also be I-594 (for IL 53), or maybe I-694 (from kurumi's site, http://www.kurumi.com/roads/3di/chicago.html)
Highest interstate designation proposed but not accepted:  I-870
Former highest US Route:  US 460
Highest secret route:  895x - best view I can find of a sign:
http://maps.google.com/maps?hl=en&ie=UTF8&ll=40.74238,-91.05649&spn=0,0.109863&z=14&layer=c&cbll=40.74241,-91.056332&panoid=1fWF-fKLHFbp7k5RvySa1Q&cbp=12,354.52,,0,7.6

[mapman1071]

Arizona

Interstate 40 (Formally 510)
US 191 (Formally US 666)
AZ 989 (Unsigned)

[national highway 1]

Arizona

Interstate 40 (Formally 510)
US 191 (Formally US 666)
AZ 989 (Unsigned)

Nope, there was an I-710 that was scrapped by NIMBYs in Tucson.

[froggie]

Nope, there was an I-710 that was scrapped by NIMBYs in Tucson.

However, I-710 was never built, whereas I-510 was.  I-710 as a number was likely never approved by AASHTO or FHWA either.

[national highway 1]

Nope, there was an I-710 that was scrapped by NIMBYs in Tucson.

However, I-710 was never built, whereas I-510 was.  I-710 as a number was likely never approved by AASHTO or FHWA either.

Yeah, 510 became AZ 51.
Say, I never knew that 710 was never approved by AASHTO or FHWA!

[froggie]

Correction:  it was approved by AASHTO in 1958.  Not sure about FHWA, but since it never got built, it's a fair chance the proposal never got as far as FHWA (or its predecessor).