Closest States Not Directly Connected by Any Route

[webny99]

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?

[ilpt4u]

Are adjacent states that do not have a shared water crossing automatically disqualified?

[CoreySamson]

For Texas it would either probably be Indiana or Utah.

[adwerkema]

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

[EpicRoadways]

Upon (very) brief inspection it looks like for Minnesota it's Kentucky to the south, West Virginia or Maryland to the east, and Oregon to the west.

[Konza]

When I populated the map for Kansas, you would think, it being "Midway USA", that there would be routes passing through it in all directions.  The reality was that the vast majority of those routes went due north-south, or straight east-west.

It isn't far from the northwest corner of Kansas to the southeast corner of Wyoming, but I do not believe the states share any routes.

Ditto with Kentucky and Tennessee, two states that border Kansas' eastern neighbor, Missouri.

[Max Rockatansky]

Appears to be South Dakota for California. 

[gonealookin]

Nevada:  New Mexico.  Laughlin NV to the point on the AZ/NM border on I-40 is about 342 miles.

[webny99]

Are adjacent states that do not have a shared water crossing automatically disqualified?

If their only shared border is on water, and they also don't have any land connections, either directly or through another state, they would probably qualify. I can't think of any examples of this though.

[keithvh]

For my current home state (Colorado), I counted 14 states without a direct connection:

There are no same route direct connections to any of the Pacific Northwest (ID, OR, WA).  I never realized that before doing this exercise, and it's slightly surprising, as the Pacific Northwest is not that far away.

No direct connections to Minnesota or Wisconsin, the only 2 midwest states in that category.

3 of the 6 New England states (ME, NH, VT).  US-6 provides a connection to the rest of New England.

The remaining 6 states are in the South (AR, FL, KY, NC, SC, TN).  The odd thing is those 6 states are non-contiguous.  US-84 just barely touches Colorado but that does provide a connection to the Deep South states of LA, MS, AL and GA.

[Roadgeekteen]

For Massachusetts, it's West Virginia unless I'm missing something.

[brad2971]

Appears to be South Dakota for California. 

Even closer: There are no direct routes between South Dakota and Utah. Which is really interesting when one realizes that there are still Delta Connection flights between Rapid City and Salt Lake City.

[CtrlAltDel]

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

[US 89]

Looks like the closest unconnected state to Utah is Oklahoma, though South Dakota and Washington are close.

[jmacswimmer]

Unless I missed something, I think Maryland & Kentucky are unconnected, which would be notable since only West Virginia (and/or Virginia, depending on your route) lies in between.

[webny99]

Looks like the closest unconnected state to Utah is Oklahoma, though South Dakota and Washington are close.

Oklahoma certainly passed the eyeball test, but I decided to double check.
Surprisingly, it's 333 miles corner to corner for Oklahoma, 311 miles corner to corner for Washington, and only 291 miles corner to corner for South Dakota.

Unless I missed something, I think Maryland & Kentucky are unconnected

US 50 flirts with Kentucky for a while, but I believe you are correct.

[frankenroad]

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

US-33 used to connect MI and WV until it was truncated in northern Indiana

[jp the roadgeek]

For CT, MA, and RI, it's WV.  NY is MI, unless you consider US 2 to be one continuous route with a silent concurrency through Canada.  Then it would be KY.   

[Roadgeekteen]

For CT, MA, and RI, it's WV.  NY is MI, unless you consider US 2 to be one continuous route with a silent concurrency through Canada.  Then it would be KY.

It's Vermont for RI.

[ozarkman417]

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

[debragga]

For Texas it would either probably be Indiana or Utah.

When I-69 is completed, Texas will be connected to Indiana

[hbelkins]

I'm assuming for purposes of this exercise, we're considering Interstate routes, US routes, and continuously numbered state routes (MSRs). Are we also considering continuous ribbons of pavement (state routes) with different route numbers? (Which inspires a new thread I'll post shortly).

Kentucky's winner would appear to be Maryland. Closest we get is US 119 running through Morgantown, WV, about 20 miles west of the state line.

Kentucky and Missouri have the distinction of being the only adjacent states that do not have a physical crossing. Of course, US 60 and US 62 link the Bluegrass to the Show-Me via Illinois, and there is a ferry between Hickman, Ky., and Dorena, Mo., but there's no direct roadway.

[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.

[kphoger]

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".

[TheHighwayMan3561]

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.