Should one-state interstates be called interstates?

[golden eagle]

Forgive me if this has been done...

The word "interstate" involves two or more states. With that in mind, how do, for example, Georgia's I-16 and Louisiana's I-12 get to be called interstates? Another Louisiana interstate, I-49, is expected to expand to other states, so no issues with that.

[jeffandnicole]

If you expand it to the "Interstate Highway System", then an interstate that is fully contained within a state is just part of the system.

[DaBigE]

The same could be said for I-43 in Wisconsin, and at one time, I-39. If you really want to keep the true definition of "interstate", then technically most Interstate spurs and loops should not be called Interstates. There's an exception to every rule.

[oscar]

If you expand it to the "Interstate Highway System", then an interstate that is fully contained within a state is just part of the system.

And if you expand it further to the "System of Interstate and Defense Highways", that brings in the intra-state Interstates in Hawaii, connecting major military bases in the Honolulu area.

Doesn't work so well for the paper Interstates in Alaska and Puerto Rico (which is neither a state nor connected to one), though each has significant military bases served by some of their Interstates.

[NE2]

yes

[Alps]

Forgive me if this has been done...

No

[Pete from Boston]

Doesn't matter -- it'll never happen. 

[dgolub]

Doesn't matter -- it'll never happen.

Right.  The changes made across the country would confuse way too many people.

[SD Mapman]

Doesn't matter -- it'll never happen.

Right.  The changes made across the country would confuse way too many people.

Yeah...

[texaskdog]

Interstates are all freeways but not all freeways are interstates.

Except of course I-180 in Wyoming.

[aerules]

Even Hawaii has interstates

[hotdogPi]

Almost every Interstate is connected to the main system (but not I-2 right now, or Alaska or Hawaii). So from almost every Interstate, you can get to another state using just the Interstate system.

Alaska and Hawaii should not have them, though.

[bzakharin]

Almost every Interstate is connected to the main system (but not I-2 right now, or Alaska or Hawaii). So from almost every Interstate, you can get to another state using just the Interstate system.

Alaska and Hawaii should not have them, though.

I wonder, aside from your exceptions, is there any piece of interstate from which you can't get to all other pieces of interstate using just the interstate system? If not, what was the last such piece and when was it connected to the rest of the system? I'm guessing this happens sometimes during construction of new interstates.

[dfilpus]

Almost every Interstate is connected to the main system (but not I-2 right now, or Alaska or Hawaii). So from almost every Interstate, you can get to another state using just the Interstate system.

Alaska and Hawaii should not have them, though.

I wonder, aside from your exceptions, is there any piece of interstate from which you can't get to all other pieces of interstate using just the interstate system? If not, what was the last such piece and when was it connected to the rest of the system? I'm guessing this happens sometimes during construction of new interstates.

I 73/74 in North Carolina was disconnected from the rest of the system from 1997 until 2013, when the US 220 freeway ( I 73/74 Future) from Asheville to Greensboro was upgraded and signed as Interstate.

[english si]

I-99 doesn't reach I-76 or I-80 yet.

[bassoon1986]

The new section of I-49 in N. Louisiana is isolated. Just about 4 or 5 miles shy of I-220.

[Scott5114]

I-99 doesn't reach I-76 or I-80 yet.

I-99 is a matter of interpretation. While there is no ramp that goes directly from I-99 to I-70/I-76 or vice versa, on I-70/I-76 there is an exit ramp signed for I-99 (without a TO). But it leads to US-220, if I remember correctly, from which you can pick up I-99. I suppose how you feel about it depends on if you feel I-70 concurs with US-30 in Breezewood, or if there is a gap in I-70 there.

[dgolub]

Interstates are all freeways but not all freeways are interstates.

Except of course I-180 in Wyoming.

Wait, how did some boulevard in Wyoming get designated an interstate?

While we're on the topic, there are also some short parts of I-78 in New Jersey and I-676 in Pennsylvania that are not freeways and have traffic lights.

[Alps]

Some people believe I-587 does not connect to the I- system. I happen to count the circle as part of the NY Thruway interchange.

[texaskdog]

Interstates are all freeways but not all freeways are interstates.

Except of course I-180 in Wyoming.

Wait, how did some boulevard in Wyoming get designated an interstate?

While we're on the topic, there are also some short parts of I-78 in New Jersey and I-676 in Pennsylvania that are not freeways and have traffic lights.

It was supposed to become one but they decided it didn't make sense, and they didn't have the heart to take it away from them.

[english si]

I-99 doesn't reach I-76 or I-80 yet.

I-99 is a matter of interpretation. While there is no ramp that goes directly from I-99 to I-70/I-76 or vice versa, on I-70/I-76 there is an exit ramp signed for I-99 (without a TO). But it leads to US-220, if I remember correctly, from which you can pick up I-99.

Certainly you can't get onto another interstate from it, as you pass "END" signs.

Plus TO banner south of I-80, TO banner north of I-70/I-76 (GMSV is poor, there might be another).

I suppose how you feel about it depends on if you feel I-70 concurs with US-30 in Breezewood, or if there is a gap in I-70 there.

No it doesn't. I-99 doesn't reach another interstate, but I-70 is continuous through Breezewood (and other similar gaps)...

I'm not concerned at all about the at-grade junctions, but the lack of designation.

[hotdogPi]

I-88's east end (in New York) has an END sign before it touches the Thruway.

[hbelkins]

Certainly you can't get onto another interstate from it, as you pass "END" signs.

You can't really use that as a guideline, because the "End I-79" sign in West Virginia is nearly a mile away from the actual terminus at I-77. It's closer to the US 119 exit just passed than to the actual end of the interstate.

[NE2]

http://en.wikipedia.org/wiki/List_of_gaps_in_Interstate_Highways#Connection_gaps
I-585.

[vdeane]

I believe I-99 officially ends at the interchange between I-99/US 220 and Alt US 220 to the PA Turnpike.