Counties that have one or more 3di, but no 2di

[NWI_Irish96]

None in Indiana, but these are nearby:

Putnam County, IL - the infamous I-180
Adams County, IL - I-172

Allegan and Van Buren Counties, MI - I-196 [forgot 94 goes through Van Buren]

[OCGuy81]

I'm sure there's a few in Kansas that I-135 goes through.

[thspfc]

Douglas, WI

[bing101]

Santa Clara county, CA


San Mateo County, CA are counties that have at least two or more 3di but no 2di.


These freeways are I-280, I-380, I-680 and I-880

[webny99]

Niagara County, NY - I-190
Livingston County, NY - I-390 (although it should be a 2di...)
Richmond County, NY - I-278
Kings County, NY - I-278, I-478
Queens County, NY - I-278, I-678, I-295, I-695
Nassau County, NY - I-495
Suffolk County, NY - I-495

Monmouth County, NJ - I-195
Ocean County, NJ - I-195
Lycoming County, PA - I-180 (but it does have future I-99...)
Windham County, CT - a very near-miss with I-395, but I-84 clips the corner.

[dvferyance]

Linn County IA where Cedar Rapids is. Only served by I-380.

[SkyPesos]

It looks like Ohio only have one instance, with I-275 in Clermont County.

Across the river, Campbell County, KY have I-275 and I-471, and no 2di.

[JayhawkCO]

I'm sure I missed one here and there, but here's what I came up with.

Marin, CA (I-580)
San Mateo, CA (I-280, I-380)
Santa Clara, CA (I-280, I-680, I-880)
Franklin, WA (I-182)
Carson City, NV (I-580)
McPherson, KS (I-135)
Harvey, KS (I-135)
Dakota, NE (I-129)
Douglas, WI (I-535)
Black Hawk, IA (I-380)
Buchanan, IA (I-380)
Benton, IA (I-380)
Linn, IA (I-380)
Adams, IL (I-172)
Putnam, IL (I-180)
Monroe, IL (I-255)
Allegan, MI (I-196)
Poinsett, AR (I-555)
Craighead, AR (I-555)
Jefferson, AR (I-530)
Madison, AL (I-565)
Dyer, TN (I-155)
Campbell, KY (I-275, I-471)
Butler, KY (I-165)
Ohio, KY (I-165)
Daviess, KY (I-165)
Hall, GA (I-985)
Pickens, GA (I-575)
Muscogee, GA (I-185)
Pinellas, FL (I-175, I-275, I-375)
Brunswick, NC (I-140)
Wayne, NC (I-795)
City of Suffolk, VA (I-664)
City of Hopewell, VA (I-295)
City of Roanoke, VA (I-581)
City of Portsmouth, VA (I-264)
Montgomery, MD (I-270, I-370, I-495)
Lycoming, PA (I-180)
Clermont, OH (I-275)
Monmouth, NJ (I-195)
Ocean, NH (I-195)
Niagara, NY (I-190)
Livingston, NY (I-390)
Richmond, NY (I-278)
Kings, NY (I-278, I-478)
Queens, NY (I-278, I-495, I-678, I-878)
Nassau, NY (I-495)
Suffolk, NY (I-495)
Plymouth, MA (I-195, I-495)
Sagadahoc, ME (I-295)

Chris

[GaryV]

Allegan Co, MI

[jmacswimmer]

Montgomery County, MD (which also happens to be the state's most populous county): I-270, I-370, & I-495.

I-95 misses MoCo by about a mile where it leaves the beltway at exit 27 in PG County, and I-70 misses MoCo by less than a mile at exit 68 in Mt. Airy (the quad-point of Frederick, Montgomery, Howard & Carroll counties is just to the south of I-70 here).

[JayhawkCO]

Montgomery County, MD (which also happens to be the state's most populous county): I-270, I-370, & I-495.

I-95 misses MoCo by about a mile where it leaves the beltway at exit 27 in PG County, and I-70 misses MoCo by less than a mile at exit 68 in Mt. Airy (the quad-point of Frederick, Montgomery, Howard & Carroll counties is just to the south of I-70 here).

I was just looking in the DC area to see if I missed any and was typing that as you posted.  Good find.

Chris

[webny99]

Montgomery County, MD (which also happens to be the state's most populous county): I-270, I-370, & I-495.
..

I was just looking in the DC area to see if I missed any and was typing that as you posted.  Good find.

You can also add Kings County, NY (Brooklyn), noted above in my reply #5.

[JayhawkCO]

Montgomery County, MD (which also happens to be the state's most populous county): I-270, I-370, & I-495.
..

I was just looking in the DC area to see if I missed any and was typing that as you posted.  Good find.

You can also add Kings County, NY (Brooklyn), noted above in my reply #5.

I meant to do that.  I somehow mentally merged Brooklyn and Staten Island when I was typing.

Chris

[US 89]

I believe I-575 just barely enters Pickens County, GA.

[Bruce]

Franklin County, WA - I-182

[ilpt4u]

No winners along Hidden I-595 east of DC? That because of I-97?

[epzik8]

Montgomery County, MD (which also happens to be the state's most populous county): I-270, I-370, & I-495.

I-95 misses MoCo by about a mile where it leaves the beltway at exit 27 in PG County, and I-70 misses MoCo by less than a mile at exit 68 in Mt. Airy (the quad-point of Frederick, Montgomery, Howard & Carroll counties is just to the south of I-70 here).

Man, you stole mine!

Rockingham County, NC will eventually have I-785.

No winners along Hidden I-595 east of DC? That because of I-97?

Both Prince George's and Anne Arundel counties have 2DIs (95 and 97).

[DandyDan]

Linn County IA where Cedar Rapids is. Only served by I-380.

I-380 also goes through Benton, Buchanan and Black Hawk Counties.

Nebraska has I-129 enter Dakota County.

[sprjus4]

The city of Portsmouth, VA only has I-264.

In the very near future, Greene and Pitt Counties in North Carolina will only have I-587. The highway has been fully approved by the FHWA and AASHTO to be designated along the US-264 freeway, it's only a matter of time until NCDOT begins to officially sign the roadway.

[Dirt Roads]

In the very near future, Greene and Pitt Counties in North Carolina will only have I-587. The highway has been fully approved by the FHWA and AASHTO to be designated along the US-264 freeway, it's only a matter of time until NCDOT begins to officially sign the roadway.

And for now, Wayne County, North Carolina only has I-795.  I-42 is coming soon.

[hbelkins]

Kentucky is fixing to get a bunch as various parkways are converted to 3di routes.

[achilles765]

St Charles Parish, LA-- Interstate 310

That may be all I can think of...

[Road Hog]

Arkansas has five counties at present. I-540 serves Sebastian County (Fort Smith) but that will change once I-49 is built out. Two counties are served only by I-530 (Jefferson and a corner of Grant). I-555 serves Poinsett and Craighead Counties.

[KCRoadFan]

Surprised to see no one has mentioned I-476 in Pennsylvania. There must be at least one along that road.

[SkyPesos]

Surprised to see no one has mentioned I-476 in Pennsylvania. There must be at least one along that road.

Actually not. In the counties I-476 goes through:

Delaware: I-95
Montgomery: I-76
Bucks: I-95
Lehigh: I-78
Carbon: I-80
Luzerne: I-80
Lackawanna: I-84