Exchanging 3di's for 2di's

[FLRoads]

Okay, I just mentioned this in another post, but it is becoming a little more commonplace in the United States for a three digit interstate (3di) to be exchanged for a two digit (2di) one.  A great example of this occurred when Interstate 181 in Tennessee, a perfectly good numbered 3di, was completely replaced by a two digit one, namely Interstate 26.  Did the need of one city to have another two digit interstate really facilitate a change in designation of a 3di freeway that had been signed in the area since the 1980's?  So now instead of having a 3di that served these northeastern Tennessee cities well (and directly connected them to I-81, a well known and traveled 2di), we have an out of place I-26, which even though signed East/West, runs in a complete opposite northeast/southwest direction for a good portion in southern Tennessee.  I thought it funny when I was traveling west on I-26 last March but in reality I was traveling northeast!!  And the fact it ends at US 11W instead of at I-81 also bothers me.  My suggestion for Johnson City would have been, we'll sign I-26 up to I-81, you can keep your portion of I-181.  But alas, that would have made some sort of sense (except for the opposite portion in southern TN) and it would have not made those in power in Johnson City very happy.  The other option would to have been to leave it alone, it's fine the way it is.

Yes, I can see they are really making good use of their extra two digit interstate...

I'm sure that when I-69 finally makes it down through the Evansville area we can say goodbye to I-164.  And the same goes for I-390 if and when I-99 reaches New York.

Any thoughts about this topic??  I'd love to hear about them!!

[Alex]

Don't forget the death of Interstate 265 in Nashville for realigned Interstate 65.

[FLRoads]

Yes, I forgot about that one.  Good point.  Yet another 3di I will never get to see or clinch...Better get to I-164 and I-390 while I can...

[Alex]

Original Interstate 880 was replaced with Interstate 80 around Sacramento for Business Loop I-80 too...

[vdeane]

Is the I-390/I-99 thing actually going to happen?  As far as I know there are no official plans to change I-390 to I-99.

[DrZoidberg]

I-97 is a prime example.

[mightyace]

Is the I-390/I-99 thing actually going to happen?  As far as I know there are no official plans to change I-390 to I-99.

Most of what I've read on the subject is just speculation.  Although, it seems to me that it would make more sense for I-99 to end in Rochester, NY instead of Painted Post!

But, who said state highway department made much sense. 

[FLRoads]

I-97 is a prime example.

Well, I-97 never replaced a 3di though...

[vdeane]

I-97 is a prime example of a 2di that should be a 3di.  I'm surprised that it even got approved as a 2di in the first place.

[rawr apples]

Wasnt 97 planned to go further than it actually does either north or south?

[FLRoads]

I am too, but the city of Annapolis wanted to be connected to a 2di, much like most other capitals in the US.  And given that it only touches I-695, it easily could have become I-995 since all other x95's are in use (even including the hidden I-595).  That would have been a better numbering for it, and we could have had the highest 3di yet!!

Another idea I thought of would be to have I-70 extend south and east on the I-695 beltway, then run down current I-97 to U.S. 50 & 301 (hidden I-595) where it would then turn east, cross the Chesapeake Bay to the 50/301 split and then continue east on a new alignment over to Dover, DE.  Then you could have an additional state capital in range of a 2di.

Or a third option could have been to just assign it but keep it a hidden route, much like I-595 is.

[Voyager]

*cough* 238.

Also, why can't they just make I-82 a 3 digit? It barely goes through anywhere that's important.

[FLRoads]

I-82 is a little different story.  When originally planning the interstate system, I-82 fit into the grid perfectly between what was then I-80N and I-90.  Just because it doesn't go through any metropolis doesn't mean it's not an important route to be 2di.  It is actually a vital link for motorists leaving the Seattle area wanting to travel to places like Boise, Salt Lake City and points south and east of there.  Plus having a 140 mile 3di that is not some sort of bypass or beltway doesn't sound appealing.

[SSOWorld]

I guess Iowa's I-380's pretty safe

[ComputerGuy]

I hope WA and ID don't exchange I-182, US 12 and I-184 for a Tri Cities-Boise 2di

[FLRoads]

I hope WA and ID don't exchange I-182, US 12 and I-184 for a Tri Cities-Boise 2di

I don't think you have anything to worry about there

[SSOWorld]

They already have I-86

[Alex]

Interstate 326 became part of an extended Interstate 77. A bit different of a concept, but it fits within the parameters of this thread. 

[akotchi]

I-95 replaced I-495 on the east side of the Capital Beltway before the latter was restored a short time later.

The I-395 Shirley Highway replaced the original alignment of I-95 into Washington D.C.

In Maine, I-95 replaced I-495 on the Maine Turnpike, and I-295 replaced the former I-95 alignment.

[Duke87]

the fact it ends at US 11W instead of at I-81 also bothers me.  My suggestion for Johnson City would have been, we'll sign I-26 up to I-81, you can keep your portion of I-181.  But alas, that would have made some sort of sense

On the contrary, it makes no sense for a route to just spontaneously change number. If it was left as it was, motorists would drive straight through an interchange, on the mainline of a highway, and all of a sudden find that the number has changed for no apparent reason. So, it made perfect sense for I-26 to assimilate I-181 like that.

Now, as for the fact that I-26 travels more north-south than it does east-west... that's an actual logic error, but the lack of available numbers in the region meant it was either give it an even number and sign it east-west or give it a very out of place odd number.
Although, I dunno, I think I might actually like it better if it were I-67 (the closest and highest available odd number).

[rawr apples]

95 never replaced 495 in DC, its just cosigned now

[akotchi]

According to Scott Kozel's Roads to the Future, the I-95 designation replaced I-495 in 1977 on the eastern half of the Beltway when I-395 took over Shirley.  The cosigning occurred in 1989.

http://www.roadstothefuture.com/Capital_Beltway.html

[rawr apples]

yup yup, because people got confused. Thought you meant today it still took over.

[FLRoads]

the fact it ends at US 11W instead of at I-81 also bothers me.  My suggestion for Johnson City would have been, we'll sign I-26 up to I-81, you can keep your portion of I-181.  But alas, that would have made some sort of sense

On the contrary, it makes no sense for a route to just spontaneously change number. If it was left as it was, motorists would drive straight through an interchange, on the mainline of a highway, and all of a sudden find that the number has changed for no apparent reason. So, it made perfect sense for I-26 to assimilate I-181 like that.

Nice point, but the original I-26 spontaneously changed into I-240 before the extension took place.  Motorists driving west on I-26 stayed on the mainline to reach I-240 east, with the designation changing right at I-40.  And isn't that what guide signs are for?  To alert motorists as to what highway they are on?  If people can't understand what the sign reads, then they don't need to be on the road.

[rawr apples]

If you think american highways spontaneously changing numbers is crazy, look at Northern Irelands motorway network...ridiculous