Iowa Highway Ends (etc.)

August 16, 2021: Looking straight ahead as the freeway bends, you can see the grading for the ramp from southbound I-380 to eastbound I-80. There’s also grading for the future ramp to westbound 80.

The I-80/I-380 interchange project has reached a big milestone: The final interior loop ramp from the original construction is shutting down.

According to an e-mail from the Iowa DOT, the new flyover ramp from southbound I-380 to eastbound I-80 will open Friday. The PDF is here, but its address indicates that it’s one that will change for other updates.

For now, the Exit 0B and 0A designations for the ramps to Des Moines and Iowa City remain intact, because there isn’t a unified exit point before a split. However, the Iowa City exit will now come before the Des Moines exit. The flyover ramp goes over I-80 but then under US 218 before merging with I-80 near the Clear Creek bridge. Here is a full diagram of the finished interchange.

Information on another stage of the Northeast Mixmaster was released online and in a public meeting August 9. This project is about expanding I-80 between I-35 and US 65.

The PDFs are here. The expansions shown in the “full build” — adding lanes on I-80, widening or replacing bridges, and making northbound 65 to westbound 80 two lanes — are years in the future. The grading/bridges component is programmed for 2024, according to the short video linked in the meeting.

Last month, WQAD did a story about the lane markers on the I-74 bridge. Each white line has a black counterpart and is called “contrast marking”. The story says the Iowa DOT is planning to add this type of marking to Iowa interstates over the next five years.

The video is embedded above, but is a set size and so the whole thing might not be seen. The video on the website does NOT autoplay.

A project 40 years in the making and project that only seems like it will have been 40 years in the making are in line for Iowa DOT public meetings in the next week.

An in-person hearing on the US 30 Missouri Valley bypass is tomorrow in that city. A bypass was first proposed in the 1980s and got so far as to be included on five-year plans, then was shelved following an Army Corps of Engineers study and public opposition in 1991.

But non-construction then, plus lessons learned from three decades of intermittent flooding, offers an opportunity. “The timing of the Iowa DOT and USACE projects creates the potential to combine a portion of the new levees in the same location as the new US 30 corridor using a single embankment that combines the levees and roadway,” says the environmental assessment that is online already (large PDF).

The bypass on the south side of Missouri Valley will start just east of the I-29 interchange and end near the F58 intersection just south of the Welcome Center.

The other meeting, scheduled for next Tuesday, is about the Northeast Mixmaster in Des Moines. Work is imminent on the most pressing need, the I-35 northbound flyover ramp. A virtual meeting (and, I hope, PDFs) will be available online that day and afterward.

The Iowa DOT has put out a “corridor preservation notice” for two areas along four-lane roads. “Corridor preservation is a tool the Iowa DOT uses to preserve land for future highway needs,” the press releases say. One location is an interchange we know is coming, and one is for an intersection that, for now, will remain so.

The first preservation zone is at the X20 intersection in Springville. Interchange proposals here were already in the public presentation stage nearly a decade ago. I can’t find earlier notices if there were any, so/but doing it now seems really delayed.

The second preservation zone is on US 20 east of the Peosta interchange. The press release does not mention an interchange. However, the newest five-year plan includes “grade and pave” at the Cox Springs Road intersection in the preservation zone. This area had an issue three years ago (KCRG), when construction of a subdivision closed a nearby road, and the city of Peosta wasn’t in complete control of the situation because the developer built the road. There was a non-fatal accident at Cox Springs Road in 2018.