Michael et al.,
Sorry about the confusion re: US 340. There *is* only one crossing in the
MD-VA-WV tripoint area - the other is some ways west near Gaylord, VA in
Clarke County.
I-684 in Connecticut is indeed the shortest non-terminating Interstate in
any one state in the U.S.
There are several urban Interstates - "3di's" (for three-digit Interstate),
as they're called -- that briefly enter one state and end there.
Of note also is the Capital Beltway (I-495) which technically enters DC
"air" over the Potomac for about 1/4 mile near Jones Point while crossing
the Woodrow Wilson Bridge. There are no signs, but there are buoys in the
water and markings on the bridge piers to indicate the crossings.
http://www.topozone.com/map.asp?lat=38.78809514084407&lon=-77.03100298084011&s=25&symshow=n
Also, when completed, I-86 through New York will dip briefly down into
Pennsylvania near Waverly.
Brendan
P.S. Scroll about 4/5 of the way down on this page and you'll see a pic of
a sign welcoming you to Greenwich on I-684 which was in place as of
sometime in 1998.
http://www.nycroads.com/roads/I-684_NY/
> That gets my vote... approximately 600 feet of the Beltway is inside DC,
> looking at Mapquest.
>
> However, I don't recall any signs saying "entering DC" / "leaving DC".
>
> If there are no signs...do the borders really exist?
There are no signs on the bridge; but IIRC there are buoys in the river
below and/or markings on the bridge piers to show where the bridge crosses
the boundary. Yes, I have been down there....
At 11:50 AM 6/9/2003, you wrote:
>well this flash dash of interstate 684 across connecticut may be
>the shortest such interstate highway interstate transit in america
>
>& for the first decades of its existence
>when i was practically living on it
>it performed this flash without so much as a raincoat
>
>not even an interstate route indicator shield saying connecticut
>rather than new york in small print above the number 684
>
>& certainly no welcome to connecticut mat
>nor welcome back to new york
>in either direction
>
>i believe the reason for all these omissions was that greenwich
>the connecticut town involved
>is quiet money
>
>but anyway i commonly amazed & amused fellow travelers thru it
>by swearing we were in connecticut during that passage
>when all their believing & seeing flatly denied this
>or at least couldnt support it
>
>i even won a few wagers over it too
>
>
>i believe there may be shorter interstate dead ends
>such as possibly interstate 66 in dc
>but dont know of any shorter state crossings
>
>
>& which reminds me
>if you &or arif &or anyone else would still like to do the pchcjbe
>aka petit central hudson central june border exhilaration
>with the shortest interstate line in america & its official blueprint
>i am still able & willing
>except monday june 16
>so please do proceed if & when ready