Closest States Not Directly Connected by Any Route

[Crown Victoria]

For PA, it would be either Michigan or Vermont. One can, however, see Michigan from roads that enter PA (I-80/I-90)...

[wriddle082]

South Carolina is a tough one, because US 52 begins there and hits just about every state to the NW except TN, but other US routes provide those connections.  I think it's Missouri, which I think is a little bit closer than Vermont.

[Konza]

For Arizona, it appears we are talking about Nebraska. 

I-10, I-40, and US 60 and 70 do a pretty good job of reaching states to the east, and the only contiguous state not connected to the north or west is Washington.

[Ketchup99]

For Pennsylvania, I believe it's Vermont. The rest of New England have I-95, as does most of the East Coast. The mid-South is mostly connected via I-81 and US-19. US-11 gets very close to Vermont, but crosses into Canada just before.

[michravera]

Inspired by the map of counties reachable by routes from Georgia, which illustrated that there are no direct routes between Georgia and Missouri. Vermont and Rhode Island were also mentioned in that thread.

Are those the best examples of two nearby states with no single routes connecting the two?
What other examples exist, and what is the closest state to yours that lacks a connection?

I believe that you can't get to Montana (nor either Dakota) by staying on any road that originates in California (at least not without the road's changing its name), but that is the closest.

[Konza]

Inspired by the map of counties reachable by routes from Georgia, which illustrated that there are no direct routes between Georgia and Missouri. Vermont and Rhode Island were also mentioned in that thread.

Are those the best examples of two nearby states with no single routes connecting the two?
What other examples exist, and what is the closest state to yours that lacks a connection?

I believe that you can't get to Montana (nor either Dakota) by staying on any road that originates in California (at least not without the road's changing its name), but that is the closest.

Interstate 15; US 91 before it was truncated at both ends.

[Ben114]

For Pennsylvania, I believe it's Vermont. The rest of New England have I-95, as does most of the East Coast. The mid-South is mostly connected via I-81 and US-19. US-11 gets very close to Vermont, but crosses into Canada just before.

I'd say PA 29 / NY 7 / VT 9 counts.

[Roadgeekteen]

For Pennsylvania, I believe it's Vermont. The rest of New England have I-95, as does most of the East Coast. The mid-South is mostly connected via I-81 and US-19. US-11 gets very close to Vermont, but crosses into Canada just before.

I'd say PA 29 / NY 7 / VT 9 counts.

I guess, but that's not one route number, which is what I was calculating. My answer might have changed if we could do same road different number.

[michravera]

Inspired by the map of counties reachable by routes from Georgia, which illustrated that there are no direct routes between Georgia and Missouri. Vermont and Rhode Island were also mentioned in that thread.

Are those the best examples of two nearby states with no single routes connecting the two?
What other examples exist, and what is the closest state to yours that lacks a connection?

I believe that you can't get to Montana (nor either Dakota) by staying on any road that originates in California (at least not without the road's changing its name), but that is the closest.

Interstate 15; US 91 before it was truncated at both ends.

You're right! So, it's South Dakota

[kendancy66]

For MN it reciprocates Colorado (it’s about 480 miles from the SW corner to Colorado’s NE corner). Originally I thought it was Kentucky, but I forgot US 52 connects them.

[kendancy66]

For MN it reciprocates Colorado (it's about 480 miles from the SW corner to Colorado's NE corner). Originally I thought it was Kentucky, but I forgot US 52 connects them.

I wondered where US-52 entered Kentucky?  I saw that US-52 enters Ohio from Indiana on I-74, then through Ohio to Huntington WV. Since it follows the Ohio River it gets pretty close though.  But after exhaustive search on Google maps now see what you are talking about.  It crosses from WV into Kentucky, south of Borderland, WV along Tug Fork.

[formulanone]

I'm going to guess Alabama for MO, and as mentioned earlier GA is probably a close 2nd.

Likewise, it looks like North Carolina, then Missouri are the two closest states without a common route designation for Alabama.

Methodology: measure distance tool to extreme point of a state using Google Maps from the Geographic Center of Alabama. Not perfect, but "about 180 miles" versus "around 250" seems good enough to me.

[hotdogPi]

I'm going to guess Alabama for MO, and as mentioned earlier GA is probably a close 2nd.

Likewise, it looks like North Carolina, then Missouri are the two closest states without a common route designation for Alabama.

Methodology: measure distance tool to extreme point of a state using Google Maps from the Geographic Center of Alabama. Not perfect, but "about 180 miles" versus "around 250" seems good enough to me.

North Carolina: I-85

[webny99]

Are we also considering continuous ribbons of pavement (state routes) with different route numbers?

Yes, although I don't think there are any states with a direct border that lack a crossing or connecting route, so it would have to be across three or more states. I can't think of very many, if any, cases where that would come into play.

But do any of those roads make a turn in the second state?  If so, then I'd say they're not a "continuous ribbon of pavement".

I thought "continuous ribbon of pavement" was only relevant at the state line specifically, because that's the only point where a number change might come into play.

[Super Mateo]

For Illinois, the closest state with no connecting routes appears to be Vermont, at about 700 miles as the crow flies.

I'm looking at a map, and it appears that Vermont, New Hampshire, and Maine are the only lower 48 states Illinois doesn't share a route with.

[hotdogPi]

For Illinois, the closest state with no connecting routes appears to be Vermont, at about 700 miles as the crow flies.

I'm looking at a map, and it appears that Vermont, New Hampshire, and Maine are the only lower 48 states Illinois doesn't share a route with.

That is correct, and it's why I chose Illinois for the initial thread that started all of this.

[formulanone]

I'm going to guess Alabama for MO, and as mentioned earlier GA is probably a close 2nd.

Likewise, it looks like North Carolina, then Missouri are the two closest states without a common route designation for Alabama.

Methodology: measure distance tool to extreme point of a state using Google Maps from the Geographic Center of Alabama. Not perfect, but "about 180 miles" versus "around 250" seems good enough to me.

North Carolina: I-85

Oh, duh on me

[kphoger]

For Illinois, the closest state with no connecting routes appears to be Vermont, at about 700 miles as the crow flies.

I'm looking at a map, and it appears that Vermont, New Hampshire, and Maine are the only lower 48 states Illinois doesn't share a route with.

That is correct, and it's why I chose Illinois for the initial thread that started all of this.

One can take US-62 from the Paseo del Norte International Bridge to the Cairo Mississippi River Bridge, meaning Illinois is also connected to Chihuahua.

Similarly, one can take US-52 from the Saskatchewan border at Portal (ND) to Illinois via the Savanna-Sabula Bridge.

And, of course, one can take I-94 from the Ontario border at the Blue Water Bridge to the south suburbs of Chicago.

Any others I'm missing?

[Super Mateo]

One can take US-62 from the Paseo del Norte International Bridge to the Cairo Mississippi River Bridge, meaning Illinois is also connected to Chihuahua.

Similarly, one can take US-52 from the Saskatchewan border at Portal (ND) to Illinois via the Savanna-Sabula Bridge.

And, of course, one can take I-94 from the Ontario border at the Blue Water Bridge to the south suburbs of Chicago.

Any others I'm missing?

I didn't catch any that added Mexican states, but I did see two other routes to go from Illinois to Chihuahua:  US 54 (if it reaches the border) and US 67.

[kphoger]

One can take US-62 from the Paseo del Norte International Bridge to the Cairo Mississippi River Bridge, meaning Illinois is also connected to Chihuahua.

Similarly, one can take US-52 from the Saskatchewan border at Portal (ND) to Illinois via the Savanna-Sabula Bridge.

And, of course, one can take I-94 from the Ontario border at the Blue Water Bridge to the south suburbs of Chicago.

Any others I'm missing?

I didn't catch any that added Mexican states, but I did see two other routes to go from Illinois to Chihuahua:  US 54 (if it reaches the border) and US 67.

US-54:  Doesn't quite reach the border, but really close!  Still, though, I didn't even check it–which is dumb, considering I've walked under the bridge just north of its southern terminus (along Paisano Drive, assuming that interchange existed in January 2002) and driven across the bridge where it enters Illinois several times.

US-67:  Good catch.

[hbelkins]

For MN it reciprocates Colorado (it's about 480 miles from the SW corner to Colorado's NE corner). Originally I thought it was Kentucky, but I forgot US 52 connects them.

Where does US-52 enter Kentucky?  US-52 enters Ohio from Indiana on I-74, then through Ohio to Huntington WV. Since it follows the Ohio River it gets pretty close though.

Twice, briefly, in Pike County, when the new route of Corridor L (which is basically US 119, but US 52 comes along from the ride north of Williamson). However, the road is maintained by WVDOT, not KYTC, so it does not officially enter Kentucky.

https://goo.gl/maps/zXkFwAj7g49qSvpo6

[MikieTimT]

Arkansas and Kansas.  Less than 50 miles corner to corner.

[Konza]

Arkansas and Kansas.  Less than 50 miles corner to corner.

Not only US 59, but US 270.

[TravelingBethelite]

For MN it reciprocates Colorado (it's about 480 miles from the SW corner to Colorado's NE corner). Originally I thought it was Kentucky, but I forgot US 52 connects them.

Where does US-52 enter Kentucky?  US-52 enters Ohio from Indiana on I-74, then through Ohio to Huntington WV. Since it follows the Ohio River it gets pretty close though.

Twice, briefly, in Pike County, when the new route of Corridor L (which is basically US 119, but US 52 comes along from the ride north of Williamson). However, the road is maintained by WVDOT, not KYTC, so it does not officially enter Kentucky.

https://goo.gl/maps/zXkFwAj7g49qSvpo6

That said, it does at least connect to KY 292.

[Flint1979]

For Michigan, it's Pennsylvania (thanks to Lake Erie) and West Virginia (which is a bit more surprising).

New York comes very close to that. It's 189 miles from Port Huron to Niagara Falls.