Iowa Notes

[Mav94]

Iowa does a pretty good job of blurring the lines between expressway and non-Interstate freeway. Which I appreciate; speed limits notwithstanding, I think that once signals and high-traffic intersections are removed in favor of interchanges and overpasses, there are better uses of funds than full freeway conversion.

That said, I know at least US 61 between Davenport and DeWitt does not allow farm machinery (Street View Link). I assume other longer full-freeway segments such as US 20 from Fort Dodge to Waterloo and US 218 south of Iowa City have similar restrictions, but I don't know what the length threshold is or what other roads would qualify.

I fully agree that many times an expressway with limited at-grade access is enough or more than enough for a road like US 20 in Iowa. The truck traffic is heavy enough to warrant the four-lane road but the overall traffic doesn't justify fully controlling the access, with all the bridges that would have to be built to let farmers move machinery.

The Des Moines Beltway notoriously does allow farm machinery because it crosses the Des Moines River.

(Also the continuous freeway section of US 20 ends at the Iowa 17 exit south of Highview; it doesn't quite make it to Fort Dodge. I only know this because I'm from the area originally and once had to make a blind left from 20 to Webster County P73 in a blizzard when I could almost see to the front of my car!)

[kphoger]

So the difference between some two lane state routes and the US 20 freeway will be 5 mph. I don't know of any states that allow 60+ on two lane roads that also don't allow 70 on non-interstate freeways

Minnesota doesn't have any non-interstates posted at 70.

I should point out that MnDOT could theoretically set a speed limit of 70 mph on a non-Interstate freeway, even if it weren't a trunk highway.

Transportation
Chapter 169 — Traffic Regulations
§ 169.14 — Speed Limits, Zones;  Radar
Subd. 4 — Establishment of zones by commissioner

On determining upon the basis of an engineering and traffic investigation that any speed set forth in this section is greater or less than is reasonable or safe under the conditions found to exist on any trunk highway or upon any part thereof, the commissioner may erect appropriate signs designating a reasonable and safe speed limit thereat, which speed limit shall be effective when such signs are erected. Any speeds in excess of such limits shall be prima facie evidence that the speed is not reasonable or prudent and that it is unlawful; except that any speed limit within any municipality shall be a maximum limit and any speed in excess thereof shall be unlawful. On determining upon that basis that a part of the trunk highway system outside a municipality should be a zone of maximum speed limit, the commissioner may establish that part as such a zone by erecting appropriate signs showing the beginning and end of the zone, designating a reasonable and safe speed therefor, which may be different than the speed set forth in this section, and that it is a zone of maximum speed limit. The speed so designated by the commissioner within any such zone shall be a maximum speed limit, and speed in excess of such limit shall be unlawful. The commissioner may in the same manner from time to time alter the boundary of such a zone and the speed limit therein or eliminate such zone.

Transportation
Chapter 169 — Traffic Regulations
§ 169.14 — Speed Limits, Zones;  Radar
Subd. 5 — Zoning within local area

When local authorities believe that the existing speed limit upon any street or highway, or part thereof, within their respective jurisdictions and not a part of the trunk highway system is greater or less than is reasonable or safe under existing conditions, they may request the commissioner to authorize, upon the basis of an engineering and traffic investigation, the erection of appropriate signs designating what speed is reasonable and safe, and the commissioner may authorize the erection of appropriate signs designating a reasonable and safe speed limit thereat, which speed limit shall be effective when such signs are erected. Any speeds in excess of these speed limits shall be prima facie evidence that the speed is not reasonable or prudent and that it is unlawful; except that any speed limit within any municipality shall be a maximum limit and any speed in excess thereof shall be unlawful. Alteration of speed limits on streets and highways shall be made only upon authority of the commissioner except as provided by law.

[Great Lakes Roads]

New bypass coming to US 30 in Missouri Valley.

[CtrlAltDel]

New bypass coming to US 30 in Missouri Valley.

Originally planned with 4 lanes, it will now have 2.

[Urban Prairie Schooner]

The 2025 Iowa Transportation Map has been released and has a very fluorescent style: https://iowadot.gov/travel-tools/maps/state-maps/iowa-transportation-map

[paulthemapguy]

I really like the Iowa DOT's map of the state. The formatting is one of the best of any state's official map.

[Molandfreak]

Good map! I just wonder why certain heritage routes and scenic byways (Loess Hills, Great River Road, Mormon Trail, Lewis & Clark Trail, and Lincoln Highway) have printed markers while others such as the Jefferson Highway and River Bluffs Scenic Byway had their markers left off.

[Great Lakes Roads]

The Wapello Bypass on US 61 will not begin construction until 2027.

An intersection on US 30 in State Center will be getting an RCI, and construction should begin in 2026.

[brad2971]

New bypass coming to US 30 in Missouri Valley.

More than $90 million dollars for a short US30 bypass of Missouri Valley?! Especially when I-880 is only a few miles away? That is an abysmal waste of resources. Frankly, Iowa DOT would be better off giving Harrison County US30 from I-29 to Iowa 127 in Logan, then relocating US30 onto either a combination of I-29/I-880/US59 or relocating US30 onto north I-29/Iowa 127.

[DandyDan]

New bypass coming to US 30 in Missouri Valley.

More than $90 million dollars for a short US30 bypass of Missouri Valley?! Especially when I-880 is only a few miles away? That is an abysmal waste of resources. Frankly, Iowa DOT would be better off giving Harrison County US30 from I-29 to Iowa 127 in Logan, then relocating US30 onto either a combination of I-29/I-880/US59 or relocating US30 onto north I-29/Iowa 127.

People following

New bypass coming to US 30 in Missouri Valley.

More than $90 million dollars for a short US30 bypass of Missouri Valley?! Especially when I-880 is only a few miles away? That is an abysmal waste of resources. Frankly, Iowa DOT would be better off giving Harrison County US30 from I-29 to Iowa 127 in Logan, then relocating US30 onto either a combination of I-29/I-880/US59 or relocating US30 onto north I-29/Iowa 127.

I can tell you, having driven that route, that Missouri Valley is a slog to drive through while following US 30. There's just too much truck and farm traffic, plus there's local traffic.

I also believe Omaha area people who like to go to the Iowa Great Lakes area use US 30 for part of their trip up there.

[iowahighways]

Shifting gears: the US 61 bypass of Mediapolis opened on September 2, according to a Facebook post from the Des Moines County Sheriff. Work to connect the bypass with the existing four-lane segment north of Burlington is still going on.

[The Ghostbuster]

The bypass is shown on Google Maps: https://www.google.com/maps/@41.010213,-91.1821089,4085m/data=!3m1!1e3?entry=ttu&g_ep=EgoyMDI1MDkyNC4wIKXMDSoASAFQAw%3D%3D.

[Great Lakes Roads]

The BNSF Fort Madison Toll Bridge will no longer be accepting cash starting on December 1st.

*The bridge does not have an electronic toll tag or E-ZPass, but you will have to pay via credit or debit card with a swipe or tap function.

https://www.mississippivalleypublishing.com/the_hawk_eye/fm-toll-bridge-going-cashless/article_98effa9a-6dd6-4b2c-96c0-7daa7184952e.html

[Molandfreak]

The BNSF Fort Madison Toll Bridge will no longer be accepting cash starting on December 1st.

*The bridge does not have an electronic toll tag or E-ZPass, but you will have to pay via credit or debit card with a swipe or tap function.

https://www.mississippivalleypublishing.com/the_hawk_eye/fm-toll-bridge-going-cashless/article_98effa9a-6dd6-4b2c-96c0-7daa7184952e.html

This bridge has such a limited regional utility that I'm not angry the BNSF isn't adopting a toll-by-plate/E-ZPass system. Anyone know if there was a history of traffic backups with the previous booth system?

[Great Lakes Roads]

IowaDOT is advancing plans to widen I-35 from Huxley to Ames to six lanes. Price tag- $100 million

As part of this project, US 30 will be lowered at I-35 and the I-35 bridges over US 30 will be replaced.

Construction to begin in Spring 2027 and expected to be completed by Fall 2030.

https://iowadot.gov/news/2025-12-11/tell-us-what-you-think-about-proposed-improvements-us-30-and-interstate-35-starting-december-15

[rte66man]

IowaDOT is advancing plans to widen I-35 from Huxley to Ames to six lanes. Price tag- $100 million

As part of this project, US 30 will be lowered at I-35 and the I-35 bridges over US 30 will be replaced.

Construction to begin in Spring 2027 and expected to be completed by Fall 2030.

https://iowadot.gov/news/2025-12-11/tell-us-what-you-think-about-proposed-improvements-us-30-and-interstate-35-starting-december-15

Isn't that where the existing widening south to Ankeny leaves off?

[iowahighways]

IowaDOT is advancing plans to widen I-35 from Huxley to Ames to six lanes. Price tag- $100 million

As part of this project, US 30 will be lowered at I-35 and the I-35 bridges over US 30 will be replaced.

Construction to begin in Spring 2027 and expected to be completed by Fall 2030.

https://iowadot.gov/news/2025-12-11/tell-us-what-you-think-about-proposed-improvements-us-30-and-interstate-35-starting-december-15

Isn't that where the existing widening south to Ankeny leaves off?

Yes.

[rte66man]

IowaDOT is advancing plans to widen I-35 from Huxley to Ames to six lanes. Price tag- $100 million

As part of this project, US 30 will be lowered at I-35 and the I-35 bridges over US 30 will be replaced.

Construction to begin in Spring 2027 and expected to be completed by Fall 2030.

https://iowadot.gov/news/2025-12-11/tell-us-what-you-think-about-proposed-improvements-us-30-and-interstate-35-starting-december-15

Isn't that where the existing widening south to Ankeny leaves off?

Yes.

I could not tell from the drawings whether they would move the southbound roadway to the west to provide a larger median like has been done at other places along 35.

[pianocello]

I could not tell from the drawings whether they would move the southbound roadway to the west to provide a larger median like has been done at other places along 35.

Looks like they will. They already did that for the new bridges over the South Skunk River, plus it makes maintenance of traffic during construction a whole lot easier.

[splashflash]

Iowa DOT studies possible closure of Peosta highway intersections, building interchange

https://www.telegraphherald.com/news/tri-state/article_1bcd9244-5712-4994-aaa9-762c5740ff90.html

PEOSTA, Iowa — Iowa Department of Transportation officials are considering options to close the U.S. 20-Cox Springs Road intersection and potentially build an interchange at Thunder Hills Road near Peosta.

The DOT recently released a feasibility study of potential improvements to the stretch of U.S. 20 between the Sundown and Swiss Valley road interchanges in Dubuque County. Two of the highway's at-grade intersections, at Cox Springs and at Thunder Hills roads, have long sparked safety concerns from area residents.

"Cox Springs is a nightmare," said George Nauman, owner of Jumble Coffee Co., which has a location in Peosta near that intersection. "It's super sketchy. I think anyone that's ever used the intersection is nervous."

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Weather conditions can make the intersection even more dangerous, Nauman said, recalling the foggy conditions Wednesday morning as he drove to Peosta.

The Iowa DOT made some safety improvements to the area in 2023, adding an offsetting right-turn lane on westbound U.S. 20 onto Thunder Hills Road and an acceleration lane onto eastbound U.S. 20 for drivers turning from Cox Springs Road.

Nonetheless, safety concerns remain, as expressed by many of the 472 respondents to a February survey, which was part of the DOT's feasibility study. Several of the comments state that some drivers fail to use the acceleration lane, while others state a westbound acceleration lane is also necessary.

Meanwhile, traffic continues to increase in the area. Peosta's population nearly tripled from 651 in 2000 to 1,908 in 2020, according to U.S. Census Bureau data, with several new developments built since, including apartments near the Thunder Hills intersection.

The study states that there were 22 crashes, none fatal, at both intersections combined from January 2024 to August 2025.

As part of the study, Iowa DOT evaluated four alternatives, though the first, making no changes, "does not address the identified safety and operational concerns and is not recommended." The study did not evaluate constructing an overpass at Cox Springs Road nor a folded diamond interchange at Thunder Hills Road due to "safety and/or constructability issues."

Alternative 2 would close access to U.S. 20 from both Cox Springs and Thunder Hills roads. A local road would be constructed connecting Adrina Drive to Enterprise Drive, thereby connecting Cox Springs Road to Peosta Street, just north of U.S. 20. Another local road would be constructed from Thunder Hills Road to Cottingham and Lost Canyon roads, giving drivers access to the Swiss Valley Road interchange. The cost of Alternative 2 would be about $10 million, the study states, about $9.4 million of which would involve the construction of the local road system.

Alternatives 3 and 4 also include completely closing off Cox Springs Road's intersection with U.S. 20.

Alternative 3 includes constructing the same local roads as in Alternative 2, but with the addition of an overpass of U.S. 20 at Thunder Hills Road, though shifted slightly east to avoid impacts to the nearby apartment complex. The overpass would connect to another future local road, 0.3 miles south of and parallel to U.S. 20, which drivers would take to access both the Sundown and Swiss Valley road interchanges. The cost of Alternative 3 would be about $21 million, the study states, about $12.1 million of which would involve the construction of the local road system.

Alternative 4 would provide direct access to U.S. 20 at Thunder Hills Road via a half-diamond interchange. There would be both off- and on-ramps on eastbound U.S. 20, an off-ramp for drivers coming off westbound U.S. 20, and a loop ramp onto westbound U.S. 20. The overall alignment of Thunder Hills Road would be shifted slightly east. The cost of Alternative 4 would be about $19 million, the study states, only about $2.3 million of which would involve the construction of local roads, because this alternative requires fewer of those.

TH - Butt's Florist - ROS - 300x250 - Oct 3 2025 - Jun 26 2026
In July, Iowa DOT announced plans to establish a corridor preservation zone for U.S. 20 from about 0.4 miles west of Sundown Road to about 0.5 miles west of Swiss Valley Road. Establishing such a zone allows the DOT to preserve land for its future needs, not by entirely restricting development but by allowing the department a chance to review proposed developments when notified by the city or county.

Hector Torres-Cacho, Iowa DOT district planner, said the alternatives represented potential "long-term solutions." He said the Thunder Hills interchange option could not realistically be completed for "at least" a decade.

However, Torres-Cacho acknowledged many area residents want more-immediate solutions, which he said the DOT is also exploring, including lowering the speed limit or posting advisory speed limits in the area.

"The soonest something could happen is in spring when the ground thaws enough for us to install updated signs," Torres-Cacho wrote in an email to the Telegraph Herald.

As of now, it is unclear how the cost of any of the alternatives would be split up. Some of the proposed local roads would be in Peosta, while others would be in unincorporated county land.

"That's a conversation we're going to be setting up with the city and county — what the cost share is," Torres-Cacho said.

Both Peosta Mayor Russ Pfab and Dubuque County Board of Supervisors Chair Harley Pothoff said they have not yet had the chance to discuss the study with their respective bodies, but they expressed a desire to address safety concerns at the intersection.

"I will be more than willing to work with the state on any project," Pothoff said. "... A lot of people have been injured and property damaged."

However, Pothoff said the county would likely need state or federal aid in constructing some of the proposed local roads.

Pfab said he wants to have Peosta residents involved in the process of making a decision about the proposals.

"It's not just us looking at it and talking to DOT — we're definitely having the citizens involved," Pfab said.

Torres-Cacho encouraged area residents to review the study, which can be accessed at Dubuque County Library District's Peosta Branch, 8342 NICC Drive

[Molandfreak]

Here is a PDF visualizing the proposed alternatives. Seems like an interchange would be nice to separate local traffic from business traffic at the existing interchange.

[Fredddie]

An intersection on US 30 in State Center will be getting an RCI, and construction should begin in 2026.

This is no longer the case. It's now going to remain as a standard intersection, but the right turn lanes off of US 30 will be offset.  The local population didn't care for the J-turn. https://www.timesrepublican.com/news/todays-news/2026/03/iowa-dot-no-longer-planning-j-turn-intersection-at-highway-30-intersection-in-state-center/

[Molandfreak]

An intersection on US 30 in State Center will be getting an RCI, and construction should begin in 2026.

This is no longer the case. It's now going to remain as a standard intersection, but the right turn lanes off of US 30 will be offset.  The local population didn't care for the J-turn. https://www.timesrepublican.com/news/todays-news/2026/03/iowa-dot-no-longer-planning-j-turn-intersection-at-highway-30-intersection-in-state-center/

I feel like oftentimes DOTs just don't see the bigger picture when these sorts of decisions are made in rural areas. Reduced conflict intersections work just fine in urban areas or outside of the harvest season, but I'm sure a lot of farm implements are using that intersection to cross into State Center in the warmer months.

[ElishaGOtis]

https://evrimagaci.org/tpg/iowa-senate-advances-legislation-on-handheld-device-ban-and-speed-limit-increase-269762

Iowa might be upping the speed limit on certain undivided paved highways from 55 mph to 60 mph... reminds me of what Minnesota did years ago.

Now official!
https://governor.iowa.gov/press-release/2026-06-01/gov-reynolds-signs-list-bills-law-june-1-2026

So the difference between some two lane state routes and the US 20 freeway will be 5 mph. I don't know of any states that allow 60+ on two lane roads that also don't allow 70 on non-interstate freeways

Minnesota doesn't have any non-interstates posted at 70.

Does Oregon count? I know they have a couple 2-lane roads explicitly authorized in statute for 70, but I don't know of any non-interstate freeways posted at such?

Technically speaking, I think Iowa DOT has the authority to put higher limits themselves but doesn't?

[xonhulu]

Does Oregon count? I know they have a couple 2-lane roads explicitly authorized in statute for 70, but I don't know of any non-interstate freeways posted at such?

There's exactly one 2-lane road with 70 mph speed limits, and that's US 95 in the southeast corner of the state.

Other than that, the only other 70 zones in Oregon are on most of I-84 east of The Dalles, and Oregon's short section of I-82. So you're right, no non-interstate freeways have 70.