Iowa Highway Ends (etc.)

A “preferred alternative” for a northwest Oskaloosa bypass of US 63 has been selected and many preliminary studies have been completed. A meeting Nov. 2 at the Oskaloosa library Middle School, the first in nearly three years, will have information about the bypass. The PDF is already online.

Under the bypass plan, US 63 would follow existing IA 163 around the southwest side of Oskaloosa, then northwest on 163 to a new interchange northwest of what was the end of IA 432. A two-lane road would angle northeast to just south of the Skunk River. This will eliminate 63 through Oskaloosa, creating an open route (save for the new interchange ramps) from US 34 to New Sharon.

The bypass would also mark the westernmost point of US 63 north of the Arkansas-Louisiana line. The Louisiana portion of 63 (the existence of which I have ranted about before) hovers roughly along the same line of longitude as the Eddyville-to-New-Sharon segment in Iowa, but is just a bit more west at Junction City.

ca. 1960: The Northeast Mixmaster was an integral part of Iowa’s interstate system from the beginning. Photo via Iowa DNR’s Historic Aerial Photo Project because the Iowa Orthographic website wasn’t working (noooo!).

The most complex interchange in Iowa is going to be turned into the most advanced interchange in Iowa.

The Northeast Mixmaster opened to east-west traffic in 1960 and north-south traffic in 1965 and 1967. In the 2000s, new north-south through lanes were built, and the north-south loops modified, but the east-west left exits remained in place.

Sixty years later, that’s all going to change. A meeting tomorrow night in Des Moines is the public’s first glimpse of a future long-term reconstruction of the Northeast Mixmaster that will eliminate the last left exits in Iowa (since I-29/480 is also going to change).

The biggest component programmed in so far, aside from rebuilding nearby surface-street bridges to accommodate changes, is a new two-lane ramp from eastbound 80 to northbound 35 plus. Currently, this is a one-lane left exit signed at 45 mph. That won’t be done until mid-2023. Along with that would be the two “farthest-out” exit ramps: WB 80 to NB 35 and EB 80 to SB 235. Here’s a map with only the earliest part shown (PDF).

Then, in 2024 and later, more new bridges and big flyover ramps would be built (PDF). The middle of the mixmaster would have three levels. Every exit with two exceptions would be two lanes. Those exceptions are the lightest traveled: EB 80 to SB 235 and NB 235 to WB 80, the latter being the only interior ramp left in the whole thing.

All of the exits would start farther back than where they are now, and all would have a single point of exit from the mainline. That is, all traffic to both directions would exit at the same time and split later.

We’ll still have what’s around now for a while, but big things are in the future.

July 5, 2013: West junction of US 30 and US 169 between Ogden and Beaver. There used to be a weigh station to the right. This is 30’s last at-grade intersection with a numbered route until IA 21.

In light of this summer’s go-ahead for “prioritization” of US 30 corridors in Iowa, one segment has a little leg up on the others.

In 1982, with the help of an early CAD program, the Iowa DOT drew up a right-of-way acquisition plan for the west US 169 interchange between Ogden and Beaver. It’s online at the Document Portal.

The four-lane running west from its current end would have to dip southward at 169, to account for the bridge over the railroad that’s just north of the current intersection. The north side of the interchange is at the current location of the intersection, with an inside loop ramp for southbound to westbound. The four-lane would rejoin current 30 (the westbound lanes) at P54 near Beaver.

The plan might require some modifications to meet current standards, but this looks like solid groundwork to move forward.