Spring 2022 Highway News Roundup

The Chestnut Street Pedestrian Plaza Project to Get Underway in Stillwater

As part of the ongoing effort to revitalize its waterfront and reclaim its downtown from the traffic in the wake of the St Croix Crossing opening, Stillwater is prepared to rebuild a two-block section of Chestnut Street leading up to the lift bridge. After having been barricaded off with temporary concrete, it will be built into a more proper pedestrian space. As Chestnut Street is still technically a trunk highway, the street will be owned by MnDOT and leased to the City of Stillwater.

Img 2509r
The corner of Chestnut and Main (photo by author)

There are several reasons the street was not turned back to the City. MnDOT wants veto power over the design due to the need for maintenance vehicles to access the Lift Bridge and to ensure a design compatible with the historic nature of the bridge. Also, it would in theory require a statewide referendum for a constitutional amendment to turn back. The original 70 charter trunk highways can in theory only be changed by a constitutional amendment. (See A History of Minnesota Trunk Highways, the original version on Streets.mn or the revised and updated version on my blog North Star Highways).

The description of Constitutional Route 45 specifies a terminus “on the banks of the St. Croix in the city of Stillwater”. So the St. Croix Crossing in Oak Park Heights doesn’t count. For some other constitutional route turnbacks including MN 50 through Lakeville MnDOT used the loophole “you can still get from town A to town B using the trunk highway system”, but there doesn’t seem to be any getting around this one.

Chestnut Street Plaza, original design
Chestnut Street Plaza, original design (graphic by city of Stillwater)

The original design that was favored by Stillwater was something more resembling a park, but this was vetoed by MnDOT as well as the state historic preservation office. Seems something resembling a street leading up to the bridge is important for the historic integrity of the bridge. Besides not resembling a street with distinct street, curb, and sidewalk, specific objections mentioned included large canopy trees blocking the view of the bridge from downtown, and the red pavers being a color not originally present.

Here is the revised design that maintains the feel of a street. The “street” portion is slightly narrowed from 24 to 20 feet to allow wider sidewalks; the “parking” area is for bicycles and benches. The trees are to the side and will be upright, columnar trees that won’t block the view of the bridge from downtown. The clear space in the middle will also provide an ideal location for portable stages. The streetlights will be retro-styled warm white LED “acorn lights” that will soon replace all the existing lighting in downtown.

New design (graphic by City of Stillwater)

The Purple Streetlights of St. Paul

Purple Street Lights of St. Paul
Purple Streetlights of St. Paul (photo by author)

Some of the new LED streetlights in St. Paul are turning purple. It’s not a tribute to Prince or the Minnesota Vikings, but a manufacturing defect. “White” LEDs are fundamentally blue, but use phosphors to convert some of the blue light to red and yellow, and the overall result appears white to us. But due to a defective batch of LED chips, the yellow phosphors are prematurely failing, leaving the red phosphor and the original blue light, with the result being an overall blue to purple cast.

The affected models are the Autobahn ATB Micro, ATB0, and ATB2 made by American Electric. MnDOT never used these particular models on the freeways (the Autobahn ATBM model that MnDOT does use is unaffected). But St. Paul and other cities have, and there’s numerous news reports of similar failures in other cities including Eau Claire, Charlotte, and Cincinnati. These lights are covered by the manufacturer’s warranty and should be reported to the appropriate jurisdiction for replacement.

The Rural Intersection Conflict Warning System (RICWS) Program Crashes

RICWS (photo by MnDOT)

A few years ago, MnDOT began a program to try to reduce crashes at dangerous rural intersections. Via use of sensors, signs would warn motorists on the main road that there might be side traffic entering, and motorists on the side road that that there was traffic on the main road. From an initial test installation at US 52 and County State Aid Highway 9 in 2013, eventually 66 were installed in the state. It sounds like a wonderful use of technology, but then someone decided to actually do a study to see how well they worked, and found that… they don’t.

Crash data was collected before and after RICWS was installed, and found that crashes actually increased by 0.25%. Further attempts to analyze intersection characteristics found clear crash reductions only at intersections with one or more of:

  • Low traffic volume on the side street (crashes actually increased statistically after activation with high traffic volumes, over 2500 vehicles a day)
  • Commercial development on one or more quadrants
  • Straight, rather than curved approaches
  • A speed limit of 55 mph

With no overall benefit to the program, it’s likely MnDOT will put the brakes on further expansion.

Interchange Design for US 52 and I-90 Unveiled

Currently motorists heading south on the US 52 freeway south of Rochester suddenly encounter a folded diamond interchange that they need to navigate to continue on to I-90 west. This interchange dates from the time US 52 was a two-lane country road and Rochester was half its current size. The I-90 bridges are now at the end of their service life and need to be replaced.

Construction will occur in 2024-2025. Along with replacing the bridges, the new design has high speed ramps for motorists between the south and the west. Replacing the ramps for the other directions isn’t planned due to low usage, the non-freeway status of US 52 to the south, and the steep hill to the east.

US 52 and I-90 Layout
Proposed Layout Graphic by MnDOT

About Monte Castleman

Monte is a long time "roadgeek" who lives in Bloomington. He's interested in all aspects of roads and design, but particularly traffic signals, major bridges, and lighting. He works as an insurance adjuster, and likes to collect maps and traffic signals, travel, recreational bicycling, and visiting amusement parks.