Iowa Notes

[74/171FAN]

[Rothman]

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"Railroad cheaped out on the bridge." -- Onondaga Lake Parkway Bridge

[Sani]

Apologies if this has already been discussed elsewhere and I missed it, but is there a long-term plan to widen I-80 east of Des Moines by taking more right-of-way to the south? I noticed a few areas where the eastbound lanes shifted to the south a bit onto new pavement before shifting back to the north — for example, at the Iowa 146 interchange at Grinnell.

[Revive 755]

^ I cannot recall Iowa ever moving towards a firm widening plan for I-80 between Des Moines and Iowa City.  The construction near Grinnell could just be the way Iowa reconstructs some of their interstates.  I-35 south of Des Moines had the southbound lanes reconstructed on a shifted alignment (compare the 2011 Streetview to the 2015, the 2021, and 2024 Streetview.

I do recall a slow plan to six lane I-80 all the way between Iowa City and Quad Cities (not that I can find any websites to back this tonight).

[edited to correct spelling error]

[rte66man]

Apologies if this has already been discussed elsewhere and I missed it, but is there a long-term plan to widen I-80 east of Des Moines by taking more right-of-way to the south? I noticed a few areas where the eastbound lanes shifted to the south a bit onto new pavement before shifting back to the north — for example, at the Iowa 146 interchange at Grinnell.

The I35 rebuilds both north and south of Des Moines factored in having a much wider median. The bridges were rebuilt way before the roadways were moved, hence the jogs you still see in places. I was happy to note the bridges will accomodate an extra lane when widening is needed.

[pianocello]

I attended a public meeting in 2018 where Iowa DOT presented long-range conceptual ideas to widen I-80 across the state. I can't seem to find anything about it now, or if it's even in the works still.

It was early enough in the process that they were only presenting alternatives, I remember some sample typical sections shifting one of the directions to the outside and others filling in the median, but they told me the shifts were more likely to be selected for design due to the lower cost for drainage. I guess the road would be torn out and rebuilt in either case.

I don't remember what the project limits were, I assume I-680 I-880 on the west side and I-280 on the east side. My guess is that the urban sections were covered under separate contracts/design phases.

[Sani]

Is the current construction at the Northeast Mixmaster working to construct this ultimate configuration from 2017 that I found, or has the project been broken down into smaller phases? It was a mess when I went through there last weekend on my way between KC and Chicago.

[Plutonic Panda]

Why do we the mainlines on Interstate 80 curve like that and not straighten them out?

[pianocello]

Why do we the mainlines on Interstate 80 curve like that and not straighten them out?

The N-S bridges aren't that old (mid- to late- '00s), so it's to align the roadways below them so that they don't need to be replaced. At least that's my assumption.

[Plutonic Panda]

Why do we the mainlines on Interstate 80 curve like that and not straighten them out?

The N-S bridges aren't that old (mid- to late- '00s), so it's to align the roadways below them so that they don't need to be replaced. At least that's my assumption.

Do you know as much as I do like straight alignment? I'm actually glad to see these preserved if they haven't reached the end of their lifespan. I don't like it when DOTs tear out bridges for projects before the end of their lifespan

[Fredddie]

The new Black Hawk Bridge is set to open on November 6!

https://www.desmoinesregister.com/story/news/iowa/2026/10/06/lansing-iowa-bridge-mississippi-river-opening-date/92118383007/
https://iowadot.gov/modes-travel/roads-highways/major-construction-projects/mississippi-river-bridge-lansing

[Revive 755]

US 20 has had the number of through lanes reduced at Holstein.  Google aerial.

[Mav94]

US 20 has had the number of through lanes reduced at Holstein.  Google aerial.

This is probably a better idea than widening the road to put in turn lanes. I imagine the effect on traffic is pretty minimal.

[kphoger]

US 20 has had the number of through lanes reduced at Holstein.  Google aerial.

This is probably a better idea than widening the road to put in turn lanes. I imagine the effect on traffic is pretty minimal.

Interestingly, nothing I see in GSV indicates that those are turn lanes at all.  Legally, I suppose you could simply drive straight through in either lane.

[Mav94]

US 20 has had the number of through lanes reduced at Holstein.  Google aerial.

This is probably a better idea than widening the road to put in turn lanes. I imagine the effect on traffic is pretty minimal.

Interestingly, nothing I see in GSV indicates that those are turn lanes at all.  Legally, I suppose you could simply drive straight through in either lane.

From the aerial view they look like left turn/merge-from-left-turn lanes to me. I drove this road a few times a year before it was four-laned.  Back when I was in high school we happened to witness a fatal accident at the junction of US 20 and US 59 east of Holstein. It's always been a troublesome stretch of road.