AARoads Forum

National Boards => General Highway Talk => Topic started by: KCRoadFan on September 27, 2021, 01:38:30 AM

Title: Longest statewide interstate segments that go through only one county
Post by: KCRoadFan on September 27, 2021, 01:38:30 AM
Building upon the thread I created about the longest state highways that only went through one county, I thought of a similar question: when we break down interstate highways into segments based on the state, we find that there are some that only go through one county in that particular state. Among these single-county statewide interstate segments, which ones are the longest? Here are the ones I've thought of:


Aside from the ones I've mentioned above, what other interstate segments are there like that, especially ones of comparable length? I'd be interested to find out more.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: jp the roadgeek on September 27, 2021, 01:52:18 AM
I-81 in WV and MD: All 26 WV miles are in Berkeley County and all 12 MD miles are in Washington County.

You can make a case for I-83 in MD, since Baltimore City is technically not a county (36 miles)

I-95 in DE and NH: 23 miles  all in New Castle County and 16 miles all in Rockingham County

I-97 is all in Anne Arundel County, MD

I-84 eastbound in MA: all 7.6 miles in Worcester County (westbound lanes clip Hampden County)

Title: Re: Longest statewide interstate segments that go through only one county
Post by: TheHighwayMan394 on September 27, 2021, 02:03:58 AM
MN's by default is I-394 at 9.7 miles all in Hennepin County. All other MN interstates enter multiple counties.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Great Lakes Roads on September 27, 2021, 02:28:59 AM
Indiana: I-469 in all of Allen County at 30.822 miles. Runner up would be I-865 in Boone County at 4.72 miles.
Illinois: I-294 in all of Cook County at 52.75 miles. Runner up would be I-270 in Madison County at 14.57 miles.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: GaryV on September 27, 2021, 06:34:12 AM
Michigan has a few 3di's (I-475, I-675, I-194, unsigned I-296) but no 2di's.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: NWI_Irish96 on September 27, 2021, 07:31:59 AM
Indiana: I-469 in all of Allen County at 30.822 miles. Runner up would be I-865 in Boone County at 4.72 miles.
Illinois: I-294 in all of Cook County at 52.75 miles. Runner up would be I-270 in Madison County at 14.57 miles.

The end sign for I-294 is just north of Lake-Cook Road.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: DJDBVT on September 28, 2021, 06:37:03 PM
I-93 in VT - 11 miles, Caledonia County
Title: Re: Longest statewide interstate segments that go through only one county
Post by: CtrlAltDel on September 28, 2021, 06:56:51 PM
Indiana: I-469 in all of Allen County at 30.822 miles. Runner up would be I-865 in Boone County at 4.72 miles.
Illinois: I-294 in all of Cook County at 52.75 miles. Runner up would be I-270 in Madison County at 14.57 miles.

The end sign for I-294 is just north of Lake-Cook Road.

We've discussed this before, and the consensus seemed to be that I-294 enters DuPage county near where those ramps to westbound I-88 branch off.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 28, 2021, 07:26:15 PM
I think the winners for both Missouri and Ohio are their respective I-270 variants:
Ohio: I-270, 55 miles in Franklin County
Missouri: I-270, 35 miles in St Louis County
Title: Re: Longest statewide interstate segments that go through only one county
Post by: US 89 on September 28, 2021, 07:43:56 PM
Undefined in Utah as all five interstates enter multiple counties.

The same is true of New Mexico and Colorado (I-270 barely enters Denver limits). Curious if there are any others.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: webny99 on September 28, 2021, 07:51:12 PM
I-490 in NY is an interesting case. It's pretty close, but clips Genesee and Ontario counties on either end for 3 counties total. About 34 of its 37 miles are in Monroe County.

Other NY interstates that are entirely within one county...

-I-481, Onondaga County, 15.1 miles
-I-690, Onondaga County, 14.2 miles
-I-99, Steuben County, 13.1 miles
-I-290, Erie County, 10.2 miles
-I-787, Albany County, 9.6 miles
-I-990, Erie County, 6.4 miles
-I-590, Monroe County, 5.0 miles
-I-781, Jefferson County, 4.9 miles
-I-790, Oneida County, 2.3 miles
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 28, 2021, 07:57:11 PM
I-490 in NY is an interesting case. It's pretty close, but clips Genesee and Ontario counties on either end for 3 counties total. About 34 of its 37 miles are in Monroe County
Similar case with I-465 in Indiana. Clips Boone County on the northwest corner for about 1 mile, and bumps into Hamilton County at its interchange with US 31 on the north loop for about 2.5 miles. Otherwise, it is in Marion County for the remaining 49 ish miles.

Other NY interstates that are entirely within one county...

-I-481, Onondaga County, 15.1 miles
-I-690, Onondaga County, 14.2 miles
-I-99, Steuben County, 13.1 miles
-I-290, Erie County, 10.2 miles
-I-787, Albany County, 9.6 miles
-I-990, Erie County, 6.4 miles
-I-590, Monroe County, 5.0 miles
-I-781, Jefferson County, 4.9 miles
-I-790, Oneida County, 2.3 miles
How about I-78 in Manhattan for less than a mile?  :bigass:
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Dirt Roads on September 28, 2021, 08:22:40 PM
All of I-485 around Charlotte are in Mecklenburg County, about 67 miles.  Amazingly, a little sliver of I-540 is not in Wake County, as the interchange with I-40 (starting point) is actually in Durham County.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: ran4sh on September 28, 2021, 08:30:14 PM
In Georgia it is I-59 which is about 20 miles in Dade County.

The only other Georgia Interstates that go through just one county, are I-24 (also Dade County), I-520 (Richmond County), and I-516 (Chatham County).
Title: Re: Longest statewide interstate segments that go through only one county
Post by: jp the roadgeek on September 28, 2021, 08:33:24 PM
CT only has 2 that qualify.

I-291 at 6.4 miles in Hartford County.

I-684 at 1.41 miles in Fairfield County.

RI only has I-195 at 4.3 miles in Providence County
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 28, 2021, 11:06:51 PM
Thought it would be interesting to pile up a leaderboard for this

(Also a correction to what I wrote above for Missouri: I-270 actually enters St Louis City for the last mile in the state, which disqualifies it from the thread. The new highest in the state is I-470 for 17 miles in Jackson County.)

StateLength (mi)InterstateCounty
California15540San Bernardino
Nevada12415Clark
North Carolina68485Mecklenburg
Ohio55270Franklin
Illinois53294Cook
Pennsylvania4690Erie
Indiana31469Allen
West Virginia2681Berkeley
Delaware2395New Castle
Georgia2024Dade
Maryland1897Anne Arundel
Michigan17275Genesee
Missouri17470Jackson
New Hampshire1695Rockingham
New York15481Onondaga
Oregon1182Umatilla
Vermont1193Caledonia
Washington11205Clark
Minnesota10394Hennepin
Connecticut6291Hartford
Colorado0--
New Mexico0--
Utah0--


Title: Re: Longest statewide interstate segments that go through only one county
Post by: TJS23 on September 28, 2021, 11:36:45 PM
I just looked at Interstate 10 in Riverside County and it looks like it ties or beats Interstate 40 by a mile
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 28, 2021, 11:38:26 PM
I just looked at Interstate 10 in Riverside County and it looks like it ties or beats Interstate 40 by a mile
I-10 also goes through LA and San Bernardino counties in the state.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: jlam on September 28, 2021, 11:40:08 PM
I will contribute Kansas. Kansas's longest is I-235, which spends all of its 16.5 miles in Sedgwick county.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Crown Victoria on September 28, 2021, 11:45:36 PM
Looks like Florida's would be I-295 around and in Jacksonville, at 60.86 miles. I-295 does run along the border between Duval County and Clay County, but is entirely within the former. Florida also has I-595 (Broward), I-395 and I-195 (Miami-Dade), I-175 and I-375 (Pinellas), and I-110 (Escambia).

For South Carolina, I-185 is entirely within Greenville County for 17.7 miles. I-585 is also only in one county (Spartanburg), as is I-126 (Richland) and I-520 while in SC (Aiken). I-526 is longer and mostly in Charleston County, but briefly enters Berkeley County. I-385 was formerly only in Greenville County, but was extended into Laurens County during the 1980's.

For New Jersey, I-676 (3.84 miles, Camden County) beats I-76 (3.08 miles, also in Camden County) and I-278 (2 miles, Union County).
Title: Re: Longest statewide interstate segments that go through only one county
Post by: TheHighwayMan394 on September 28, 2021, 11:57:49 PM
Iowa: I-880, Pottawatomie (16)
Montana: I-115, Silver Bow (1)
South Dakota: I-190, Pennington (1)
Wisconsin: I-894, Milwaukee (10)

North Dakota has no qualifying routes, as unsigned I-194 exists in two counties.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: MinecraftNinja on September 29, 2021, 12:04:55 AM
New Jersey: I-76 in Camden County.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: empirestate on September 29, 2021, 12:32:55 AM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:
Title: Re: Longest statewide interstate segments that go through only one county
Post by: US20IL64 on September 29, 2021, 12:33:25 AM
Indiana: I-469 in all of Allen County at 30.822 miles. Runner up would be I-865 in Boone County at 4.72 miles.
Illinois: I-294 in all of Cook County at 52.75 miles. Runner up would be I-270 in Madison County at 14.57 miles.

The end sign for I-294 is just north of Lake-Cook Road.

We've discussed this before, and the consensus seemed to be that I-294 enters DuPage county near where those ramps to westbound I-88 branch off.

294 is on the County Line, between 22nd and 31st street overpasses.
So, winner [for north 1/2 of IL] is I-190, in Cook, 3 miles. I-180 is in 2 cos.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: GaryV on September 29, 2021, 07:41:50 AM
That's I-475 in Genesee Co., MI
Title: Re: Longest statewide interstate segments that go through only one county
Post by: clong on September 29, 2021, 03:09:02 PM
For AL, there are 4:
1. I-459 33.5 miles all in Jefferson
2. I-165 4.8 miles all in Mobile
3. I-759 4.6 miles all in Etowah
4. I-359 2.4 miles all in Tuscaloosa

I-10 is only in 2 counties - Mobile and Baldwin for its' 67 miles in AL.
I-565 also enters 2 counties - Limestone and Madison for its' nearly 22 miles.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: webny99 on September 29, 2021, 03:18:52 PM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:

What am I missing here? Wikipedia and my own eyes agree that I-787 is entirely in Albany County.

Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 29, 2021, 03:27:18 PM
Updated leaderboard. Also removed I-294 from the list based on the replies. New highest for Illinois is now I-270 in Madison County for 15 miles.

StateLength (mi)InterstateCounty
California15540San Bernardino
Nevada12415Clark
North Carolina68485Mecklenburg
Florida61295Duval
Ohio55270Franklin
Texas49410Bexar
Pennsylvania4690Erie
Alabama34459Jefferson
Indiana31469Allen
West Virginia2681Berkeley
Delaware2395New Castle
Georgia2024Dade
Maryland1897Anne Arundel
South Carolina18185Greenville
Kansas17235Sedgwick
Michigan17475Genesee
Missouri17470Jackson
Iowa16880Pottawatomie
New Hampshire1695Rockingham
Illinois15270Madison
New York15481Onondaga
Oregon1182Umatilla
Vermont1193Caledonia
Washington11205Clark
Minnesota10394Hennepin
Wisconsin10894Milwaukee
Connecticut6291Hartford
New Jersey4676Camden
Montana1115Silver Bow
South Dakota1190Pennington
Wyoming1180 :DLaramie
Colorado0--
New Mexico0--
Utah0--
Title: Re: Longest statewide interstate segments that go through only one county
Post by: JayhawkCO on September 29, 2021, 03:59:09 PM
I'll contribute a couple.

None for Alaska or North Dakota.

Hawai'i - I-H1 is 27.16 miles long in Honolulu County.
Arizona - I-15 is 29.43 miles long in Mohave County.

Chris
Title: Re: Longest statewide interstate segments that go through only one county
Post by: NWI_Irish96 on September 29, 2021, 04:17:30 PM
I'll contribute a couple.

None for Alaska or North Dakota.

Hawai'i - I-H1 is 27.16 miles long in Honolulu County.
Arizona - I-15 is 29.43 miles long in Mohave County.

Chris

I'm guessing there aren't any interstates in Hawaii that aren't all in one county.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: oscar on September 29, 2021, 04:26:39 PM
I'm guessing there aren't any interstates in Hawaii that aren't all in one county.

Right. And all of Hawaii's Interstates are entirely in Honolulu County. When Hawaii became a state, it asked for approval of an Interstate entirely in Hawaii County (which would've been longer than Interstate H-1), but that proposal was rejected.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: 1 on September 29, 2021, 04:29:41 PM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:

What am I missing here? Wikipedia and my own eyes agree that I-787 is entirely in Albany County.

The northern end is ambiguous. One of the two possibilities has it crossing the Hudson.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: jlam on September 29, 2021, 04:46:54 PM
I'll do Arkansas, as I don't believe anyone else has. It seems to be I-430, where all nearly 13 miles of it are in Pulaski county.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: JCinSummerfield on September 29, 2021, 04:53:29 PM
Updated leaderboard. Also removed I-294 from the list based on the replies. New highest for Illinois is now I-270 in Madison County for 15 miles.

StateLength (mi)InterstateCounty
California15540San Bernardino
Nevada12415Clark
North Carolina68485Mecklenburg
Florida61295Duval
Ohio55270Franklin
Pennsylvania4690Erie
Alabama34459Jefferson
Indiana31469Allen
West Virginia2681Berkeley
Delaware2395New Castle
Georgia2024Dade
Maryland1897Anne Arundel
South Carolina18185Greenville
Kansas17235Sedgwick
Michigan17275Genesee
Missouri17470Jackson
Iowa16880Pottawatomie
New Hampshire1695Rockingham
Illinois15270Madison
New York15481Onondaga
Oregon1182Umatilla
Vermont1193Caledonia
Washington11205Clark
Minnesota10394Hennepin
Wisconsin10894Milwaukee
Connecticut6291Hartford
New Jersey4676Camden
Montana1115Silver Bow
South Dakota1190Pennington
Wyoming1180 :DLaramie
Colorado0--
New Mexico0--
Utah0--

I-275 doesn't go into Genesee County in Michigan.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 29, 2021, 04:55:24 PM
Updated leaderboard. Also removed I-294 from the list based on the replies. New highest for Illinois is now I-270 in Madison County for 15 miles.

StateLength (mi)InterstateCounty
California15540San Bernardino
Nevada12415Clark
North Carolina68485Mecklenburg
Florida61295Duval
Ohio55270Franklin
Pennsylvania4690Erie
Alabama34459Jefferson
Indiana31469Allen
West Virginia2681Berkeley
Delaware2395New Castle
Georgia2024Dade
Maryland1897Anne Arundel
South Carolina18185Greenville
Kansas17235Sedgwick
Michigan17275Genesee
Missouri17470Jackson
Iowa16880Pottawatomie
New Hampshire1695Rockingham
Illinois15270Madison
New York15481Onondaga
Oregon1182Umatilla
Vermont1193Caledonia
Washington11205Clark
Minnesota10394Hennepin
Wisconsin10894Milwaukee
Connecticut6291Hartford
New Jersey4676Camden
Montana1115Silver Bow
South Dakota1190Pennington
Wyoming1180 :DLaramie
Colorado0--
New Mexico0--
Utah0--

I-275 doesn't go into Genesee County in Michigan.
Oops, that is supposed to be I-475.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Great Lakes Roads on September 29, 2021, 05:03:00 PM
RI- I-195 through Providence County for 4.30 miles.
NJ- I-676 through Camden County for 4.75 miles.
OK- I-240 through Oklahoma County for 16.8 miles. It will still be the longest interstate to go through one county in Oklahoma if FHWA approves the "extended" version of I-240.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: jlam on September 29, 2021, 05:31:29 PM
ID - I-184 through Ada County for 3.6 miles

KY - I-265 through Jefferson County for 25 miles

LA - I-210 through Calcasieu Parish for 12.4 miles




Title: Re: Longest statewide interstate segments that go through only one county
Post by: JayhawkCO on September 29, 2021, 05:59:26 PM
ME: I-395 5.00 miles in Penobscot County
MA: I-190 is 19.26 miles in Worcester County
MS: I-110 is 4.10 miles in Harrison County
NE: I-680 is 13.32 miles in Douglas County
TN: I-240 is 19.27 miles in Shelby County
TX: I-410 is 49.488 miles in Bexar County
VT: I-93 is 11.104 miles in Caledonia County
VA: I-564 is 3.03 miles in the City of Norfolk

Chris
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Rothman on September 29, 2021, 06:25:52 PM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:

What am I missing here? Wikipedia and my own eyes agree that I-787 is entirely in Albany County.

The northern end is ambiguous. One of the two possibilities has it crossing the Hudson.
Meh.  It's not ambiguoius.  It crosses the bridge. :)
Title: Re: Longest statewide interstate segments that go through only one county
Post by: skluth on September 29, 2021, 08:06:33 PM
I'm confused about the thought process regarding I-270 near St Louis. SkyPeso's suggestion of 35 miles in I-270 in St Louis County (SLC), MO, is longer than the listed I-470 in Jackson County. (I used to live in South SLC and can verify it never leaves SLC in Missouri. The 35 miles sounds about right.) I thought I-270 wasn't in the table because it does cross state lines into another county, but so does the longest entry, I-40 in California as does the other half of I-270 in Madison County, IL.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 29, 2021, 08:13:38 PM
I'm confused about the thought process regarding I-270 near St Louis. SkyPeso's suggestion of 35 miles in I-270 in St Louis County (SLC), MO, is longer than the listed I-470 in Jackson County. (I used to live in South SLC and can verify it never leaves SLC in Missouri. The 35 miles sounds about right.) I thought I-270 wasn't in the table because it does cross state lines into another county, but so does the longest entry, I-40 in California as does the other half of I-270 in Madison County, IL.
Based on what I’m getting at from the op, it only has to go through a single county in a state for it to count. OP listed 3 2di that goes through only one county in one of the states it goes through, but overall, goes through multiple counties adding up other states.

As for I-270, it actually does enter the City of St Louis (an independent city) between the Riverview Dr exit and the MO-IL line. So it doesn’t count for MO because it enters 2 county equivalent jurisdictions in MO, and counts for IL for entering one county in IL.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: empirestate on September 29, 2021, 08:20:26 PM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:

What am I missing here? Wikipedia and my own eyes agree that I-787 is entirely in Albany County.

The northern end is ambiguous. One of the two possibilities has it crossing the Hudson.
Meh.  It's not ambiguoius.  It crosses the bridge. :)

Yes, I-787 enters Rensselaer County, even if secretly. It's 10.16 miles from McCarty Ave. in Albany (https://goo.gl/maps/mHyxm5ziXbz65QLN9) to 8th St. in Troy (https://goo.gl/maps/ep6aztYPwfvXxiWFA). Signage and in-field evidence of this may vary, but that part of the route has never been de-designated.

Doesn't change anything as far as its status for this topic, but there you go.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: skluth on September 29, 2021, 08:21:40 PM
I'm confused about the thought process regarding I-270 near St Louis. SkyPeso's suggestion of 35 miles in I-270 in St Louis County (SLC), MO, is longer than the listed I-470 in Jackson County. (I used to live in South SLC and can verify it never leaves SLC in Missouri. The 35 miles sounds about right.) I thought I-270 wasn't in the table because it does cross state lines into another county, but so does the longest entry, I-40 in California as does the other half of I-270 in Madison County, IL.
Based on what I’m getting at from the op, it only has to go through a single county in a state for it to count. OP listed 3 2di that goes through only one county in one of the states it goes through, but overall, goes through multiple counties adding up other states.

As for I-270, it actually does enter the City of St Louis (an independent city) between the Riverview Dr exit and the MO-IL line. So it doesn’t count for MO because it enters 2 county equivalent jurisdictions in MO, and counts for IL for entering one county in IL.

Oops. I forgot about that sliver along Riverview.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: webny99 on September 29, 2021, 08:35:37 PM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:

What am I missing here? Wikipedia and my own eyes agree that I-787 is entirely in Albany County.

The northern end is ambiguous. One of the two possibilities has it crossing the Hudson.
Meh.  It's not ambiguoius.  It crosses the bridge. :)

Yes, I-787 enters Rensselaer County, even if secretly. It's 10.16 miles from McCarty Ave. in Albany (https://goo.gl/maps/mHyxm5ziXbz65QLN9) to 8th St. in Troy (https://goo.gl/maps/ep6aztYPwfvXxiWFA). Signage and in-field evidence of this may vary, but that part of the route has never been de-designated.

Doesn't change anything as far as its status for this topic, but there you go.

The Wikipedia page explicitly states that the entire route is in Albany County, so I guess that's inaccurate. Google has an I-787 shield north of NY 7, so I guess that's inaccurate as well.

But to me the bigger issue is the I-787 to NY 787 transition. Not sure how it can be both a continuous and disjointed route.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: jlam on September 29, 2021, 08:39:05 PM
Georgia2024Dade
Shouldn't that be I-59?
Title: Re: Longest statewide interstate segments that go through only one county
Post by: empirestate on September 29, 2021, 08:50:28 PM
The Wikipedia page explicitly states that the entire route is in Albany County, so I guess that's inaccurate. Google has an I-787 shield north of NY 7, so I guess that's inaccurate as well.

Well, not entirely inaccurate—that is how the route is signed for thru traffic. There's just a bit of a difference between how the route is signed as a touring route, and what it actually is behind the scenes. It's one in a long line of such instances around the state, another notable one being NY 15. (It was signed for many years concurrent with I-390 and NY 17, despite not "actually" existing south of Wayland.)

Quote
But to me the bigger issue is the I-787 to NY 787 transition. Not sure how it can be both a continuous and disjointed route.

It takes some getting used to, indeed. Even if you look it up on the FHWA map viewer (https://hepgis.fhwa.dot.gov/fhwagis/#), you will see both the official route turning east into Troy, and an I-787 shield continuing north toward Cohoes. But again, it's really just a matter of thinking of the publicly-signed routes as being a modified/idealized/simplified version of the actual inventory of routes and roadways.

For myself, I just think of NY 787 being topologically a spur from I-787, not a direct continuation of it. Wouldn't be the only spot where a continuous designation takes a turn through an interchange, while a different route follows the through roadway!
Title: Re: Longest statewide interstate segments that go through only one county
Post by: webny99 on September 29, 2021, 09:02:53 PM
For myself, I just think of NY 787 being topologically a spur from I-787, not a direct continuation of it. Wouldn't be the only spot where a continuous designation takes a turn through an interchange, while a different route follows the through roadway!

I guess it's not completely non-sensical, but it's not like there's any reason why the section over the bridge needs to be I-787. It's already NY 7.

There's certainly plenty of examples where the through roadway makes a turn and another route continues straight, but this has to be one of the only examples where the route that makes the turn and the route that continues have the same number. This means that technically three of the four approaches to the NY 7/I-787/NY 787 interchange have the same number.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: vdeane on September 29, 2021, 09:28:13 PM
-I-787, Albany County, 9.6 miles

Welllllll… :confused:

What am I missing here? Wikipedia and my own eyes agree that I-787 is entirely in Albany County.

The northern end is ambiguous. One of the two possibilities has it crossing the Hudson.
Meh.  It's not ambiguoius.  It crosses the bridge. :)

Yes, I-787 enters Rensselaer County, even if secretly. It's 10.16 miles from McCarty Ave. in Albany (https://goo.gl/maps/mHyxm5ziXbz65QLN9) to 8th St. in Troy (https://goo.gl/maps/ep6aztYPwfvXxiWFA). Signage and in-field evidence of this may vary, but that part of the route has never been de-designated.

Doesn't change anything as far as its status for this topic, but there you go.

The Wikipedia page explicitly states that the entire route is in Albany County, so I guess that's inaccurate. Google has an I-787 shield north of NY 7, so I guess that's inaccurate as well.

But to me the bigger issue is the I-787 to NY 787 transition. Not sure how it can be both a continuous and disjointed route.
Technically it starts where the exit 23 toll booths were (the lanes to US 9W where the Southside Route was supposed to be are reference route 912S).  And it's not disjointed; NY 787 technically begins where "exit 9E" (aka actual I-787) diverts off.  This is not what's signed (mostly (https://www.google.com/maps/@42.7397981,-73.6852498,3a,25.4y,294.16h,88.21t/data=!3m6!1e1!3m4!1seq_u24F8uRk3BN9SO-MEYg!2e0!7i16384!8i8192)), but it's how it's inventoried.  I-787 is interesting that way.

For myself, I just think of NY 787 being topologically a spur from I-787, not a direct continuation of it. Wouldn't be the only spot where a continuous designation takes a turn through an interchange, while a different route follows the through roadway!
In a way it's actually the opposite of I-283/PA 283.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: SkyPesos on September 29, 2021, 09:31:17 PM
The Wikipedia page explicitly states that the entire route is in Albany County, so I guess that's inaccurate.
Similar case: The Wikipedia page I-294 also states that it's entirely in Cook County, though that has already been proved wrong earlier in this thread.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: rlb2024 on September 29, 2021, 09:46:34 PM
Tennessee:  I-240, 19.27 miles, all in Shelby County.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: empirestate on September 29, 2021, 10:48:13 PM
I guess it's not completely non-sensical, but it's not like there's any reason why the section over the bridge needs to be I-787. It's already NY 7.

I'm pretty sure the reason is to have an Interstate designation serving Troy. (And not just being fussy about city limits—you literally have to cross the river to get to Troy there, so that's why they would have sent the Interstate that way.) And also, NY 787 was not yet a thing when these designations were dreamed up, so there would have been no reason not to end it in Troy.

If it happened today, it may well be different, but it was some years ago, and those decisions were never undone. So it remains to this day!

Quote
There's certainly plenty of examples where the through roadway makes a turn and another route continues straight, but this has to be one of the only examples where the route that makes the turn and the route that continues have the same number. This means that technically three of the four approaches to the NY 7/I-787/NY 787 interchange have the same number.

It's a quirk, to be sure. But you do also have a similar situation with I-890/NY 890. I'm not sure exactly where FHWA thinks I-890 ends, but I'd bet it's not a seamless thru transition onto NY 890.

And then there's I-790…

Technically it starts where the exit 23 toll booths were (the lanes to US 9W where the Southside Route was supposed to be are reference route 912S).

I know NYSDOT made that swap. FHWA's map suggests they eventually did too, but that seems to make their mileage figure just a bit high.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Bruce on September 30, 2021, 12:59:55 AM
I'm guessing there aren't any interstates in Hawaii that aren't all in one county.

Right. And all of Hawaii's Interstates are entirely in Honolulu County. When Hawaii became a state, it asked for approval of an Interstate entirely in Hawaii County (which would've been longer than Interstate H-1), but that proposal was rejected.

Got more details? Sounds like an interesting rabbit hole to investigate.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Dirt Roads on September 30, 2021, 09:03:45 AM
I'm guessing there aren't any interstates in Hawaii that aren't all in one county.

Right. And all of Hawaii's Interstates are entirely in Honolulu County. When Hawaii became a state, it asked for approval of an Interstate entirely in Hawaii County (which would've been longer than Interstate H-1), but that proposal was rejected.

Got more details? Sounds like an interesting rabbit hole to investigate.

There's only two shipping ports on the coast of the Big Island (Hilo on the east coast, and Kawaihae on the west coast) and the Interstate highway was proposed to connect the two.  Hawai'i route H-19 (part of the Hawai'i Belt) almost connects the two ports, but H-19 turns south at a T-bone intersection with H-270 as you get the coast overlooking the port.  The town of Kawaihae is old and industrial (perhaps the only place on the Big Island that fits that description), but all of the restaurants and diners are quaint and friendly.

The path of H-200 Saddle Road (Daniel Inouye Highway) takes a more direct path between the west coast and east coast.  We saw a few big trucks heading over the "saddle" between Mauna Kea and Mauna Loa, but it is a steep road with very few services.  That was a problem for this boy from West Virginia.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: Rothman on September 30, 2021, 12:01:43 PM
Heh.  WV is filled with steep roads with few services. :D
Title: Re: Longest statewide interstate segments that go through only one county
Post by: vdeane on September 30, 2021, 12:23:01 PM
I guess it's not completely non-sensical, but it's not like there's any reason why the section over the bridge needs to be I-787. It's already NY 7.

I'm pretty sure the reason is to have an Interstate designation serving Troy. (And not just being fussy about city limits—you literally have to cross the river to get to Troy there, so that's why they would have sent the Interstate that way.) And also, NY 787 was not yet a thing when these designations were dreamed up, so there would have been no reason not to end it in Troy.

If it happened today, it may well be different, but it was some years ago, and those decisions were never undone. So it remains to this day!

Quote
There's certainly plenty of examples where the through roadway makes a turn and another route continues straight, but this has to be one of the only examples where the route that makes the turn and the route that continues have the same number. This means that technically three of the four approaches to the NY 7/I-787/NY 787 interchange have the same number.

It's a quirk, to be sure. But you do also have a similar situation with I-890/NY 890. I'm not sure exactly where FHWA thinks I-890 ends, but I'd bet it's not a seamless thru transition onto NY 890.

And then there's I-790…

Technically it starts where the exit 23 toll booths were (the lanes to US 9W where the Southside Route was supposed to be are reference route 912S).

I know NYSDOT made that swap. FHWA's map suggests they eventually did too, but that seems to make their mileage figure just a bit high.
It's worth noting that NY 7 originally followed what is now NY 2 in Albany County, so the bridge would have been I-787 alone.  Additionally, that freeway was planned to become part of I-88; had I-88 been built as planned, it's likely I-787 would have been truncated and the north end at least would have matched the signage.

Regarding I-890, it takes the exit 1B ramps to end at Thruway exit 26.  Oddly enough, I-690 isn't shown doing the same at exit 39; it ends as the signage implies.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: empirestate on September 30, 2021, 11:36:01 PM
Regarding I-890, it takes the exit 1B ramps to end at Thruway exit 26.  Oddly enough, I-690 isn't shown doing the same at exit 39; it ends as the signage implies.

Perhaps this is due to I-690's former Thruway interchange being a non-freeway connection?

Also while we're on the subject, I-590 doesn't end at I-490—it ends under I-490, where it just becomes NY 590, I think at the city line. The distinction seems trifling, but the point is that the notion that an Interstate designation should physically touch another at its terminus is something of an invention.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: vdeane on October 01, 2021, 12:42:08 PM
Regarding I-890, it takes the exit 1B ramps to end at Thruway exit 26.  Oddly enough, I-690 isn't shown doing the same at exit 39; it ends as the signage implies.

Perhaps this is due to I-690's former Thruway interchange being a non-freeway connection?
Good point.  Especially since while NY 890's bridge over the Mohawk River was long planned, NY 890 itself is even more recent than I-690's extension to present-day exit 39.
Title: Re: Longest statewide interstate segments that go through only one county
Post by: cpzilliacus on October 17, 2021, 10:27:59 PM
You can make a case for I-83 in MD, since Baltimore City is technically not a county (36 miles)

No.  Baltimore City is an independent city or county equivalent) and is not part of Baltimore County or Anne Arundel County (the only counties that have borders with Baltimore City).  It is the only independent city in Maryland (Virginia has the most of any state).

An easy way to make this determination is to look at the FIPS code (https://en.wikipedia.org/wiki/FIPS_county_code) (officially withdrawn but still widely used) for a suspected independent city - if it is five numeric characters, then it qualifies as a county-equivalent jurisdiction.

Baltimore County FIPS code:  24005
Baltimore City FIPS code:  24510