PHOTO BY J. MORRISON The Interstate 80 bridge over the Mississippi River, officially named the Fred Schwengel Memorial Bridge for an Iowa congressman, is scheduled to be replaced at the end of this decade. It’s seen here from the Illinois welcome center looking toward LeClaire, Iowa, Nov. 3, 2022.

The second-most-expensive project in the Iowa Department of Transportation’s 2027-31 highway construction program needs more money.

The Gordon Drive Viaduct in Sioux City is scheduled to be replaced in 2027-30 at a cost of $206 million. It’s marked as “underfunded” with the note that it’s eligible for funding from other sources.

The other underfunded project is converting the at-grade intersection of Iowa Highway 27/58 at Greenhill Road in Cedar Falls into a full interchange in 2029 for $54.65 million. (All figures in this story are rounded, with fiscal year or years of significant work.)

The biggest project, cost-wise, in the $4.2 billion highway plan that was approved by the Iowa Transportation Commission on June 9 is replacement of the Interstate 80 bridge over the Mississippi River. The Illinois Department of Transportation is the lead agency in the project, which also includes rebuilding the I-80/88 interchange. If things go as planned, Iowa will contribute $241.2 million in 2028-30 for a replacement on the downriver side of the current bridge.

The third-largest project is a milestone one: completion of the U.S. Highway 61 expressway in eastern Iowa. The segment from Mediapolis to Iowa 78, which includes a new roadbed and interchange, will wrap up soon. The segment between Iowa 78 and Iowa 92, including a bypass of Wapello, is slated for $165.7 million and will last the entire five-year span.

Following that is the perpetual construction zone known as Interstate 35/80 in Des Moines’ western suburbs. The ramp from southbound I-35 to eastbound I-235 at the west mixmaster is being changed from a cloverleaf loop to a flyover ramp. This $125 million project is hitting the ground running; construction lettings are set for July 28, the first availability in the fiscal year. That’s in addition to finishing lane expansion between University and Douglas avenues ($13.3 million).

Rounding out the top five projects in cost is the U.S. 30 Missouri Valley bypass ($103.7 million, 2028 and 2031).

Here is a collection of the most expensive and/or interesting items in the plan. Both Dickinson and Hardin counties have no projects scheduled.

Interstates

The big stuff for upgrading I-380 to six lanes between the North Liberty and Swisher exits starts in 2030. So far, $56.2 million has been allocated. This entry includes the rare mystery-box category of “miscellaneous.”

After I-35 is six-laned between Iowa 210 and U.S. 30 in the next year ($58.5 million), a separate project to expand/replace the U.S. 30 interchange itself will start in 2029 ($65.74 million).

Completion of the expansion of I-80 between the northeast mixmaster and U.S. 65 is in 2027 ($33.25 million).

A $34.1 million grade-and-pave for the northbound lanes of I-35 from the Cumming exit into Polk County in 2027 is intriguing because it connects to where the interstate expands to three lanes. Perhaps that will be extended southward.

New bridges for I-80 capable of carrying three lanes of traffic in each direction are still ahead for the exits at U.S. 169 ($30.4 million, 2028 and 2030), U.S. 63 ($33 million, 2029/31), Iowa 21 ($17.7 million, 2027-28), and Iowa 149 ($32 million, 2027/29).

The southbound lanes of I-29 between Iowa 175 and the Blencoe exit will be replaced in 2028 ($25 million).

Original rest areas to be replaced are on I-80 eastbound near Mitchellville ($17 million in 2028-29, with a massive expansion of truck parking), I-29 in both directions near Onawa (northbound 2027, southbound 2029, $10.25 million), I-80 westbound near Underwood ($6.2 million, 2031), and the eastbound I-80 truck parking site north of Wilton ($7 million, 2030).

Intersections with four-lane roads

The U.S. 151 Springville exit remains set for 2028 ($27.3 million).

Ideas for U.S. 20 on the west side of Dubuque have gone through multiple iterations dating back to 2013. The final plan, $12.5 million in 2028, adds a frontage road to the south side of 20 but keeps at-grade stoplights with Old Highway Road, Northwest Arterial, and Crescent Ridge.

It will cost $32 million to build an interchange for U.S. 30 on the west side of Nevada in 2028-29. Once the exit for 610th Avenue/18th Street, by Van Wall Equipment, is completed, all remaining at-grade intersections from the east side of Nevada to Ames will be closed, making U.S. 30 a full freeway there.

As part of a $2.9 million Revitalize Iowa’s Sound Economy grant for De Witt to expand an industrial park, the intersection of U.S. 30 and 300th Street will become the second “reduced conflict intersection” in the state. This type of intersection, also known as a “J-turn,” which bans direct left turns from the intersecting road, has met stiff resistance elsewhere in the state. That includes in State Center, where residents successfully persuaded the DOT to install offset right-turn lanes on U.S. 30 instead. Those will make it easier for through traffic to change lanes.

An offset right-turn lane is also coming to westbound Iowa 100 at 44th Street in Marion ($500,000 Traffic Safety Improvement Program award). Nearby, next year, left turns will be banned from Munier Road onto eastbound Iowa 100.

Two roundabouts will be placed on U.S. 30 on the south side of Boone in 2027 ($6.7 million).

Speaking of roundabouts

In the upcoming year alone, they’re coming to the U.S. 18/71 intersection on the north side of Spencer ($5.7 million), the U.S. 59/Iowa 2 intersection just south of Shenandoah ($2.8 million), and U.S. 69/126th Street west of Elkhart ($3.2 million, a surprise addition).

The project to replace the U.S. 30/59 bridges over the Union Pacific tracks in Denison in 2029 includes turning the intersections with U.S. 30 on both ends into roundabouts. These somewhat complicated three-way intersections have not changed since they were implemented in 1962.

Notable bridges

Replacement costs for two bridges on Iowa 175 have skyrocketed. The bridge over the Des Moines River near Dayton first appeared in the 2022 plan, scheduled for 2026, at $8.4 million. It’s been delayed twice and is now programmed for 2028 at $15.5 million. A bridge in Lake View is still set for 2029, but it’s gone from $3.9 million to $8 million.

The Burlington Street (Iowa 1) bridge over the Iowa River in Iowa City is technically a bridge pair that falls under two jurisdictions. The state has $6.9 million included for replacement in 2030, but the city of Iowa City expects overall costs to be in the neighborhood of $30 million.

The long U.S. 34 bridge over the East Nodaway River and Union Pacific Railroad by Corning will be replaced in 2030 ($21.2 million).

Rehabilitation of the Iowa 149/Business U.S. 63 viaduct in Ottumwa has been pushed back, from $33.8 million in 2029 to $36.9 million in 2031. A paving project just to its north, from Second Street past Woodland Avenue, will take place in 2028 ($7 million).

New to the list this year are new bridges on opposite borders of the state: Iowa 175 at Decatur, Nebraska, and U.S. 67 (the Centennial Bridge) at Rock Island. Those won’t start until 2031 at the earliest, and the latter has $60 million set aside that year alone.

Southeast 14th Street in Des Moines

U.S. 69, “Des Moines River to N of Maury Ave in Des Moines (State Share),” has managed to go on a journey while going nowhere. It originally appeared in the 2019-23 plan, scheduled for 2022, at a cost of $752,000. Then it kept getting pushed back, and now it’s scheduled for 2027 at a cost of $3.3 million.

If you have ridden the Iowa State Fair shuttle to the State Capitol or Center Street parking garage, you are indirectly familiar with the need for this project. This is where the shuttle buses turn left off Martin Luther King Jr. Parkway onto 12th Street, then left again onto Maury Avenue, then left again onto Southeast 14th Street. A March 2025 map shows the plan to close Maury on the west side of the intersection, taking out the Git-N-Go gas station in the process, and create a curved connection from MLK to Southeast 14th.

This project includes widening the median enough to create a southbound left-turn lane onto Harriet Street, just south of the once-iconic La Pizza House. That building was demolished in 2025, the same year co-founder Abbie Polito died.

The Maury Avenue project is separate from two substantial projects on Southeast 14th to the immediate south and north: replacement of the Des Moines River bridge in 2029 ($25 million) and replacement of the MLK/railroad viaduct in 2030 ($52.1 million).

And finally

The Legislative Services Agency estimates the Iowa DOT has nearly 1,800 signs that will need $52 overlays or $171 replacements when the speed limit on rural two-lane roads increases from 55 to 60 mph on July 1. Sammy Hagar, eat your heart out.