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Regional Boards => Central States => Topic started by: ethanhopkin14 on January 18, 2023, 01:59:01 PM

Title: Iowa Interstate 880
Post by: ethanhopkin14 on January 18, 2023, 01:59:01 PM
I have never been to Iowa or the Omaha area but was perusing the googs and saw the former I-680 was renumbered I-880 to avoid driver confusion.  Now, I am a bit ignorant to things, but I don't really understand how that keeps down confusion when you are detoured off I-29 to use I-880 and I-80 as your way to Council Bluffs.  I figured having it numbered I-680 does the exact same thing.  Can someone explain this to me?

I feel like a lot of times states renumber (or truncate) designations for "driver confusion", I have a hard time understanding the logic. 
Title: Re: Iowa Interstate 880
Post by: Bobby5280 on January 18, 2023, 02:47:04 PM
I saw no issue with the previous configuration where they overlapped I-680 onto I-29. If anything, I think adding an additional I-880 route number into that combo would do more to confuse thru traffic taking I-680 to avoid downtown Omaha. Previously I-680 ran along the entire length of that bypass route. Now there are 3 different numbered Interstates to take to do essentially the same thing.

At least this "I-880" route has a couple exits along it and has some significant length. It's not like I-865 in Indianapolis; that one has no exits. It really only functions as a couple exit ramps between I-465 & I-74. "I-270 Spur" in the DC metro appears more worthy of having its own Interstate number, yet it's signed as some kind of lesser route.
Title: Re: Iowa Interstate 880
Post by: triplemultiplex on January 18, 2023, 03:14:25 PM
Resigning was cheaper than raising the grade of 680 so it doesn't flood out.
Apparently, Iowa plans on 680 getting flooded so often in the future that it doesn't pay for it to be a continuous route all the way back to I-80?

That's my interpretation of how the change went down.
Title: Re: Iowa Interstate 880
Post by: ethanhopkin14 on January 18, 2023, 03:17:38 PM
Quote from: triplemultiplex on January 18, 2023, 03:14:25 PM
Resigning was cheaper than raising the grade of 680 so it doesn't flood out.
Apparently, Iowa plans on 680 getting flooded so often in the future that it doesn't pay for it to be a continuous route all the way back to I-80?

That's my interpretation of how the change went down.

That doesn't make a whole lot of sense to me.  I thought it was I-29 that flooded (south of the 680 split) because it hugged the Missouri River.  The rest of 680 would be irrelevant for this exercise.  Am I understanding wrong?
Title: Re: Iowa Interstate 880
Post by: triplemultiplex on January 18, 2023, 04:16:36 PM
Pretty sure it was 680 that was underwater on the Iowa side of the river...
Looking it up, it looks like we're both right.

680 was completely swamped from the 29 south interchange west to almost the bridge.
And portions of 29 were under water both directions from the 680 west interchange.

680 got it worse with water flowing over the highway and completely destroying the pavement.
Title: Re: Iowa Interstate 880
Post by: SD Mapman on January 21, 2023, 03:36:57 PM
Quote from: Bobby5280 on January 18, 2023, 02:47:04 PM
I saw no issue with the previous configuration where they overlapped I-680 onto I-29. If anything, I think adding an additional I-880 route number into that combo would do more to confuse thru traffic taking I-680 to avoid downtown Omaha. Previously I-680 ran along the entire length of that bypass route. Now there are 3 different numbered Interstates to take to do essentially the same thing.

At least this "I-880" route has a couple exits along it and has some significant length. It's not like I-865 in Indianapolis; that one has no exits. It really only functions as a couple exit ramps between I-465 & I-74. "I-270 Spur" in the DC appears more worthy of having its own Interstate number, yet it's signed as some kind of lesser route.
The idea, at least as I remember from the press releases at the time, was that when IowaDOT announced that I-680 was closed due to flooding, people avoided ALL of 680, not just the river bottoms part. The redesignation to I-880 was so you could specify exactly which area had closures without confusing motorists. Additionally, they were originally separate routes (I-880 was I-80N before it became part of I-680).

Quote from: triplemultiplex on January 18, 2023, 03:14:25 PM
Resigning was cheaper than raising the grade of 680 so it doesn't flood out.
Apparently, Iowa plans on 680 getting flooded so often in the future that it doesn't pay for it to be a continuous route all the way back to I-80?

That's my interpretation of how the change went down.

That would require about 2-3 miles worth of embankments on I-680, which would hydraulically change the flood path of any potential Missouri floodwaters in unexpected ways. Also, they'd probably have to raise I-29, which would be even more embankments. The smarter idea would have been to just not build the interstates in the river bottoms in the first place, but that didn't happen.
Title: Re: Iowa Interstate 880
Post by: triplemultiplex on January 23, 2023, 12:12:21 PM
The best solution is for a couple more bridge segments across the floodplain so large floods are not 'impounded' by the earthen embankment the way the last big flood was.
Part of crossing a river includes crossing it's floodplain so if you don't give the river enough room to flood, it'll make room.

It seems to me like back when they were first building interstates, designers tended to low-ball the spans they'd need over rivers because landfill is cheaper than bridge.   The result was an economical crossing, but one that restricts the floodplain in a way that increases stream velocity under the span.  More velocity = more energy for erosion.  (Which, as an angler, usually makes for a decent fishing spot just downstream from a bridge since the river scours a deep spot that fish like.  Though with low gradient streams like out in Nebraska, the river will scour a hole during a flood, but fill it right back in with sediment as the flood abates and energy levels drop.)

Long story short, bring up the grade on I-680 in Iowa and provide more openings to pass floodwaters.
Title: Re: Iowa Interstate 880
Post by: J N Winkler on January 23, 2023, 01:16:09 PM
Given all the reports of levee breaks that crop up when the Missouri floods between Sioux City and Kansas City, I wonder about the adequacy of investment in flood control in general.  At least in southwestern Iowa, the floodworks are in the hands of small local flood control boards, and I can see them not having the resources to ensure I-29 and I-680 stay open.
Title: Re: Iowa Interstate 880
Post by: The Ghostbuster on January 23, 2023, 02:39:38 PM
As you all probably know, Interstate 880 was Interstate 80N until 1973, Interstate 680 until 2019, and Interstate 880 now. It probably should have been renumbered to 880 in 1973; either that or it should have stayed Interstate 680.
Title: Re: Iowa Interstate 880
Post by: ethanhopkin14 on January 23, 2023, 02:43:34 PM
Quote from: SD Mapman on January 21, 2023, 03:36:57 PM
The idea, at least as I remember from the press releases at the time, was that when IowaDOT announced that I-680 was closed due to flooding, people avoided ALL of 680, not just the river bottoms part. The redesignation to I-880 was so you could specify exactly which area had closures without confusing motorists. Additionally, they were originally separate routes (I-880 was I-80N before it became part of I-680).

This, sadly, is the most feasible explanation to the number change.  I often underestimate the stupidity of the average person.
Title: Re: Iowa Interstate 880
Post by: Revive 755 on January 23, 2023, 11:13:25 PM
Quote from: The Ghostbuster on January 23, 2023, 02:39:38 PM
As you all probably know, Interstate 880 was Interstate 80N until 1973, Interstate 680 until 2019, and Interstate 880 now. It probably should have been renumbered to 880 in 1973; either that or it should have stayed Interstate 680.

Or it should have stayed I-680 with the southern section of I-680 becoming I-629  :spin:
Title: Re: Iowa Interstate 880
Post by: skluth on January 24, 2023, 01:24:46 PM
Quote from: J N Winkler on January 23, 2023, 01:16:09 PM
Given all the reports of levee breaks that crop up when the Missouri floods between Sioux City and Kansas City, I wonder about the adequacy of investment in flood control in general.  At least in southwestern Iowa, the floodworks are in the hands of small local flood control boards, and I can see them not having the resources to ensure I-29 and I-680 stay open.

I worry about the merits of levees for flood control generally. Without allowing for high water to flood the floodplains, the flooding simply moves downriver to more populated areas around Kansas City and St Louis. Downtown St Charles frequently floods as do the smaller downtowns of Grafton and Alton IL (floodwaters from the Missouri frequently flow slightly upstream from the Missouri/Mississippi confluence) and older neighborhoods of St Louis. It makes sense to have flood control in more densely populated places along riverbanks like downtown St Louis. It makes far less sense to have levees and highway embankments so high as to push flooding downstream in farmland. Farmers and those who moved into floodplains because they like being near the river won't like it but flooding was an acceptable if inconvenient fact of life when Americans first started farming the incredibly fertile river floodplains in the 1800s.
Title: Re: Iowa Interstate 880
Post by: iowahighways on January 24, 2023, 05:57:48 PM
Previous thread about the I-680 to I-880 changeover: https://www.aaroads.com/forum/index.php?topic=25812.0

Side note: The Omaha World-Herald on February 9, 1974, published a photo of the signs that existed at the time of the I-80N to I-680 changeover ("North Omaha" wouldn't be added as a destination until sometime after the rest of I-680 west of I-29 was completed):
(https://img.newspapers.com/img/img?institutionId=0&user=1878946&id=886939801&clippingId=114176848&width=557&height=522&crop=202_5600_1693_1616&rotation=0)
Title: Re: Iowa Interstate 880
Post by: mrose on January 28, 2023, 03:49:28 AM
For years on our trips back to Lincoln, we would occasionally use the entire length of I-680 as an Omaha bypass, though I'm not sure if that was the intent when both of them were built. I always thought it was strange that 680 didn't just arc across back to I-80, but I guess the (880) leg was built and completed much earlier.

All things being equal, it was a few miles longer than just staying on I-80, but this was at a time when I-80 through Omaha seemed like it was eternally under construction.

The (880) leg almost never had traffic on it, to my recollection.

Title: Re: Iowa Interstate 880
Post by: US 89 on January 28, 2023, 10:35:48 AM
Quote from: iowahighways on January 24, 2023, 05:57:48 PM
Previous thread about the I-680 to I-880 changeover: https://www.aaroads.com/forum/index.php?topic=25812.0

Side note: The Omaha World-Herald on February 9, 1974, published a photo of the signs that existed at the time of the I-80N to I-680 changeover ("North Omaha" wouldn't be added as a destination until sometime after the rest of I-680 west of I-29 was completed):
(https://img.newspapers.com/img/img?institutionId=0&user=1878946&id=886939801&clippingId=114176848&width=557&height=522&crop=202_5600_1693_1616&rotation=0)

That’s so Dakota of them.
Title: Re: Iowa Interstate 880
Post by: paulthemapguy on February 07, 2023, 09:46:54 AM
I really didn't understand the need for a renumbering. I especially don't understand why Iowa used up all their even x80's so that no additional ones can be signed in the future. 429, 629, and 829 are all unused!
Title: Re: Iowa Interstate 880
Post by: zzcarp on February 07, 2023, 12:47:02 PM
Quote from: paulthemapguy on February 07, 2023, 09:46:54 AM
I really didn't understand the need for a renumbering. I especially don't understand why Iowa used up all their even x80's so that no additional ones can be signed in the future. 429, 629, and 829 are all unused!

I'd assert they chose the last remaining even x80 since the freeway has been derivative of I-80 since its opening (I-80N, I-680, and now I-880). I agree that an x29 may have been a better choice, especially since (now) I-880 is the detour route for I-29 around Council Bluffs.

As a cross-country traveler, I think it made more sense when it was all I-680 so it could function as a full Omaha bypass loop. However, if the location of the flooding closures caused confusion, well, they should take local preferences into account over someone like me who sees it at most a handful of times a year.
Title: Re: Iowa Interstate 880
Post by: Hobart on February 08, 2023, 01:31:12 AM
Quote from: zzcarp on February 07, 2023, 12:47:02 PM
Quote from: paulthemapguy on February 07, 2023, 09:46:54 AM
I really didn't understand the need for a renumbering. I especially don't understand why Iowa used up all their even x80's so that no additional ones can be signed in the future. 429, 629, and 829 are all unused!

I'd assert they chose the last remaining even x80 since the freeway has been derivative of I-80 since its opening (I-80N, I-680, and now I-880). I agree that an x29 may have been a better choice, especially since (now) I-880 is the detour route for I-29 around Council Bluffs.

As a cross-country traveler, I think it made more sense when it was all I-680 so it could function as a full Omaha bypass loop. However, if the location of the flooding closures caused confusion, well, they should take local preferences into account over someone like me who sees it at most a handful of times a year.

I agree on the confusion part; if it's confusing enough to change a number on a 50 year old highway, its probably worth changing.

It also makes me giddy in a way... There are two states to exhaust all possible loop 3DIs in a state for I-80... first is California, which used every number; second is, out of every state and population center, Iowa. The state with some corn.
Title: Re: Iowa Interstate 880
Post by: ethanhopkin14 on February 09, 2023, 11:20:42 AM
Quote from: Hobart on February 08, 2023, 01:31:12 AM
Quote from: zzcarp on February 07, 2023, 12:47:02 PM
Quote from: paulthemapguy on February 07, 2023, 09:46:54 AM
I really didn't understand the need for a renumbering. I especially don't understand why Iowa used up all their even x80's so that no additional ones can be signed in the future. 429, 629, and 829 are all unused!

I'd assert they chose the last remaining even x80 since the freeway has been derivative of I-80 since its opening (I-80N, I-680, and now I-880). I agree that an x29 may have been a better choice, especially since (now) I-880 is the detour route for I-29 around Council Bluffs.

As a cross-country traveler, I think it made more sense when it was all I-680 so it could function as a full Omaha bypass loop. However, if the location of the flooding closures caused confusion, well, they should take local preferences into account over someone like me who sees it at most a handful of times a year.

I agree on the confusion part; if it's confusing enough to change a number on a 50 year old highway, its probably worth changing.

It also makes me giddy in a way... There are two states to exhaust all possible loop 3DIs in a state for I-80... first is California, which used every number; second is, out of every state and population center, Iowa. The state with some corn.

Yeah, but.....All but the new I-880 get help from other states.  I feel like it kinda cheapens the deal a bit when the 3di in question is an extension of the interstate from another state when that other state has the city in which the populated center of the region belongs to, in it.  It goes in the books as a touchdown for your state, but it really should be more of an assist.
Title: Re: Iowa Interstate 880
Post by: pianocello on February 09, 2023, 06:47:17 PM
Quote from: ethanhopkin14 on February 09, 2023, 11:20:42 AM
Quote from: Hobart on February 08, 2023, 01:31:12 AM
It also makes me giddy in a way... There are two states to exhaust all possible loop 3DIs in a state for I-80... first is California, which used every number; second is, out of every state and population center, Iowa. The state with some corn.

Yeah, but.....All but the new I-880 get help from other states.  I feel like it kinda cheapens the deal a bit when the 3di in question is an extension of the interstate from another state when that other state has the city in which the populated center of the region belongs to, is in it.  It goes in the books as a touchdown for your state, but it really should be more of an assist.

Hey, I'll take it... A screen pass from midfield with a run into the end zone still counts as a 50-yard TD pass even if it's the receiver and blockers doing all the work  :)
Title: Re: Iowa Interstate 880
Post by: ethanhopkin14 on February 10, 2023, 03:35:26 PM
Quote from: pianocello on February 09, 2023, 06:47:17 PM
Hey, I'll take it... A screen pass from midfield with a run into the end zone still counts as a 50-yard TD pass even if it's the receiver and blockers doing all the work  :)

This does go into a frequently visited subject by myself.  The amount of 3dis that exist in a state because they got "help" from another state. 

West Virgina's only 3di (I-470) may be a bypass for the West Virgina city involved and is mostly in West Virgina but smells like it would not have existed had Ohio not come up to them and said, "we are building an interstate bypass here...you will comply."  I mean, it's number in West Virgina is totally predicated on what available numbers are left out of Ohio's I-X70s.   

If El Paso could get ion the move and plan an I-210 bypass, then they could force New Mexico to actually have a 3di (preferred alignment is north of Chaparral, NM)!!
Title: Re: Iowa Interstate 880
Post by: The Ghostbuster on February 10, 2023, 06:18:15 PM
I think the closest El Paso could get to getting an "Interstate 210" , would be to renumber TX Loop 375 to 210.  A Fictional Highways idea if there ever was one!
Title: Re: Iowa Interstate 880
Post by: WhitePoleRD on January 27, 2025, 04:08:33 PM
880 should have been 329.

It doesn't come back to itself and the vast majority of traffic is WB from Des Moines to Sioux City.
Title: Re: Iowa Interstate 880
Post by: The Ghostbuster on January 27, 2025, 04:16:40 PM
Given it was Interstate 680 and Interstate 80N before, the Interstate 880 designation suits the corridor just fine. Maybe the US 20/US 75 bypass of Sioux City should have been Interstate 329 (or an extended Interstate 129).
Title: Re: Iowa Interstate 880
Post by: Revive 755 on January 27, 2025, 10:37:26 PM
Quote from: paulthemapguy on February 07, 2023, 09:46:54 AMI really didn't understand the need for a renumbering. I especially don't understand why Iowa used up all their even x80's so that no additional ones can be signed in the future. 429, 629, and 829 are all unused!

They could always try duplicating I-280 again (see GRM Barcodes 101277396 and 101277396 from the AASHTO route numbering archive)  :spin:
Title: Re: Iowa Interstate 880
Post by: Henry on January 27, 2025, 10:51:30 PM
Quote from: Revive 755 on January 27, 2025, 10:37:26 PM
Quote from: paulthemapguy on February 07, 2023, 09:46:54 AMI really didn't understand the need for a renumbering. I especially don't understand why Iowa used up all their even x80's so that no additional ones can be signed in the future. 429, 629, and 829 are all unused!

They could always try duplicating I-280 again (see GRM Barcodes 101277396 and 101277396 from the AASHTO route numbering archive)  :spin:
Given that an I-280 already exists in the Quad Cities area, this is not possible. Also, I don't see a problem with I-880, especially since it was I-680 for many years.
Title: Re: Iowa Interstate 880
Post by: Gnutella on March 10, 2025, 07:04:14 PM
To me, I-880 can be justified as the shortcut for long-distance traffic from I-80 westbound to I-29 northbound, and I-29 southbound to I-80 eastbound. I would venture that most of the traffic on I-880 uses it for that purpose, rather than bypassing Omaha. Besides, the former I-680 concurrency with I-29 seemed goofy to me, because a 10-mile concurrency between two different 16-mile segments seemed to break the continuity in the route.
Title: Re: Iowa Interstate 880
Post by: The Ghostbuster on March 10, 2025, 10:27:12 PM
I didn't mind the Interstate 29/680 overlap. Of course, I've never been along the 680 corridor. It was probably for the best that the former 680 east of Interstate 29 was renumbered to Interstate 880. At least, that was better than renumbering it back to Interstate 80N.
Title: Re: Iowa Interstate 880
Post by: SEWIGuy on March 11, 2025, 09:08:40 AM
Quote from: WhitePoleRD on January 27, 2025, 04:08:33 PM880 should have been 329.

It doesn't come back to itself and the vast majority of traffic is WB from Des Moines to Sioux City.

880 is fine.

Title: Re: Iowa Interstate 880
Post by: hotdogPi on March 11, 2025, 09:21:23 AM
Quote from: SEWIGuy on March 11, 2025, 09:08:40 AMthe vast majority of traffic is WB from Des Moines to Sioux City.

Assuming it's true, this is probably the most convincing reason it should have an odd first digit. It's one of those "straight lines" like IL I-155 and KS I-135.
Title: Re: Iowa Interstate 880
Post by: Rothman on March 11, 2025, 10:29:58 AM
Quote from: SEWIGuy on March 11, 2025, 09:08:40 AM
Quote from: WhitePoleRD on January 27, 2025, 04:08:33 PM880 should have been 329.

It doesn't come back to itself and the vast majority of traffic is WB from Des Moines to Sioux City.

880 is fine.



So was 680.
Title: Re: Iowa Interstate 880
Post by: kphoger on March 11, 2025, 11:07:53 AM
Quote from: WhitePoleRD on January 27, 2025, 04:08:33 PM880 should have been 329.

It doesn't come back to itself and the vast majority of traffic is WB from Des Moines to Sioux City.
Quote from: SEWIGuy on March 11, 2025, 09:08:40 AM880 is fine.
Quote from: Rothman on March 11, 2025, 10:29:58 AMSo was 680.

It should be 238.
Title: Re: Iowa Interstate 880
Post by: The Ghostbuster on March 11, 2025, 11:12:15 AM
There already is an Interstate 238 in the Bay Area, and that is already one too many.
Title: Re: Iowa Interstate 880
Post by: kphoger on March 11, 2025, 11:16:00 AM
Quote from: The Ghostbuster on March 11, 2025, 11:12:15 AMThere already is an Interstate 238 in the Bay Area

I-680 and I-880 say hi.
Title: Re: Iowa Interstate 880
Post by: PColumbus73 on March 13, 2025, 10:20:00 PM
Quote from: kphoger on March 11, 2025, 11:16:00 AM
Quote from: The Ghostbuster on March 11, 2025, 11:12:15 AMThere already is an Interstate 238 in the Bay Area

I-680 and I-880 say hi.

I-99 (W)  :awesomeface:
Title: Re: Iowa Interstate 880
Post by: kphoger on March 14, 2025, 10:26:43 AM
Quote from: PColumbus73 on March 13, 2025, 10:20:00 PMI-99

Yeah, I'd be OK with renaming Iowa Interstate 880 to I-99.  Good suggestion.
Title: Re: Iowa Interstate 880
Post by: webny99 on March 14, 2025, 10:29:38 AM
Quote from: kphoger on March 14, 2025, 10:26:43 AM
QuoteI-99

Yeah, I'd be OK with renaming Iowa Interstate 880 to I-99.  Good suggestion.

Good thing I-880 would become available for existing I-99.  :awesomeface:
Title: Re: Iowa Interstate 880
Post by: kphoger on March 14, 2025, 10:49:47 AM
Quote from: webny99 on March 14, 2025, 10:29:38 AMGood thing I-880 would become available for existing I-99.

The existence of I-880 in Iowa, as it is, has no bearing on the numbering of I-99 in Pennsylvania or New York.
Title: Re: Iowa Interstate 880
Post by: webny99 on March 14, 2025, 10:55:09 AM
Quote from: kphoger on March 14, 2025, 10:49:47 AMThe existence of I-880 in Iowa, as it is, has no bearing on the numbering of I-99 in Pennsylvania or New York.

But it sure would in the hypothetical scenario of I-99 being stolen for I-880 that I was responding to...
Title: Re: Iowa Interstate 880
Post by: kphoger on March 14, 2025, 11:07:11 AM
Ah, you're assuming there couldn't be two I-99s.  Gotcha.
Title: Re: Iowa Interstate 880
Post by: webny99 on March 14, 2025, 11:29:59 AM
Quote from: kphoger on March 14, 2025, 11:07:11 AMAh, you're assuming there couldn't be two I-99s.  Gotcha.

Well, technically there's *already* two I-99's that will hopefully be connected someday.

But yes, I am operating under the assumption that any duplicate interstate routes are either intended to be connected or could theoretically be connected following a general path in their signed direction.

I-99 is a north/south designation, so having one in Iowa and one in Pennsylvania would be a non-starter for that reason, among, of course, many others.
Title: Re: Iowa Interstate 880
Post by: Rothman on March 14, 2025, 11:43:18 PM
880 goes to Jersey Shore.
Title: Re: Iowa Interstate 880
Post by: Mav94 on March 26, 2025, 05:18:24 PM
I just want to point out one use case that, IMO, justifies the renumbering to 880. Prior to the renumbering, I-680 connected to I-80 at both ends, with about 30 miles of I-80 in between the two ends. When the joint section of I-29 and (former) I-680 flooded, the rest of I-680 would obviously remain open on the west and north sides of Omaha. Traffic coming from the west that wanted to head north on I-29 out of Council Bluffs would normally use I-680 as a shortcut.

When the joint section of I-29 and I-680 was impassible, it couldn't do that, obviously. So how do you redirect that traffic in a way that isn't completely confusing to (a) that traffic and (b) those drivers who needed to use the still-open section of I-680? You'd need to find a way to say "If you're going to I-29 north, don't use this end of I-680, use the other end, which by the way is about 30 miles down the road, but if you're trying to get to Dodge Street or US 75, go ahead and use this end of I-680." The easiest way to do that is to give the straightline spur between I-29 and I-80 a different number. They didn't have to give it that number, but numbering the whole thing I-680 created a problem. Not in Pottawatamie County, but in southwest Omaha.
Title: Re: Iowa Interstate 880
Post by: Bobby5280 on March 26, 2025, 09:13:54 PM
I have less of a problem with "I-880" being assigned to the former I-680 in Iowa than I do other signing choices on some other Interstate highway segments. Take I-865 in Indianapolis for instance. It has no exits between its start and end points at I-65 and I-465. The road is effectively just two fairly long exit ramps than a real Interstate.
Title: Re: Iowa Interstate 880
Post by: The Ghostbuster on March 27, 2025, 03:58:12 PM
I'm okay with the Interstate 865 designation in Indianapolis. I don't think it made sense to have the Interstate 465 designation go west, east and south from the 465/865 interchange. The redesignation of Interstate 680-to-Interstate 880 was also a logical redesignation.
Title: Re: Iowa Interstate 880
Post by: kphoger on March 27, 2025, 04:20:54 PM
Quote from: The Ghostbuster on March 27, 2025, 03:58:12 PMI'm okay with the Interstate 865 designation in Indianapolis. I don't think it made sense to have the Interstate 465 designation go west, east and south from the 465/865 interchange.

But the argument is that it wouldn't carry I- signs of its own at all.

From SB I-65, it would be signed "TO I-465 EAST".
From WB I-465, it would be signed "TO I-65 NORTH".
From NB I-465, it would be signed "TO I-65 NORTH".

The only information left out in that scenario is the fact that SB I-65 traffic can also use it to get to the 86th Street and 71st Street exits of I-465—which are not accessible by waiting till the 'proper' I-465 interchange.
Title: Re: Iowa Interstate 880
Post by: WillWeaverRVA on March 27, 2025, 05:45:03 PM
Quote from: PColumbus73 on March 13, 2025, 10:20:00 PM
Quote from: kphoger on March 11, 2025, 11:16:00 AM
Quote from: The Ghostbuster on March 11, 2025, 11:12:15 AMThere already is an Interstate 238 in the Bay Area

I-680 and I-880 say hi.

I-99 (W)  :awesomeface:

Use NCDOT logic. I-87.
Title: Re: Iowa Interstate 880
Post by: iowahighways on March 27, 2025, 05:45:36 PM
Quote from: Mav94 on March 26, 2025, 05:18:24 PMI just want to point out one use case that, IMO, justifies the renumbering to 880. Prior to the renumbering, I-680 connected to I-80 at both ends, with about 30 miles of I-80 in between the two ends. When the joint section of I-29 and (former) I-680 flooded, the rest of I-680 would obviously remain open on the west and north sides of Omaha. Traffic coming from the west that wanted to head north on I-29 out of Council Bluffs would normally use I-680 as a shortcut.

When the joint section of I-29 and I-680 was impassible, it couldn't do that, obviously. So how do you redirect that traffic in a way that isn't completely confusing to (a) that traffic and (b) those drivers who needed to use the still-open section of I-680? You'd need to find a way to say "If you're going to I-29 north, don't use this end of I-680, use the other end, which by the way is about 30 miles down the road, but if you're trying to get to Dodge Street or US 75, go ahead and use this end of I-680." The easiest way to do that is to give the straightline spur between I-29 and I-80 a different number. They didn't have to give it that number, but numbering the whole thing I-680 created a problem. Not in Pottawatamie County, but in southwest Omaha.

And that is exactly why the Iowa DOT made the change to I-880. Flooding of the Missouri River in 2011 and 2019 caused I-680 at the state line to close for extended periods of time.