Minnesota Department of Transportation

511 Travel Info

Hwy 169, Hwy 22 Minnesota River Flood Mitigation

Mankato, Saint Peter

Traffic impacts

Motorists using Hwy 169 to access St. Julien Street and Hwy 22 in the St. Peter area are using a re-designed intersection (Reduced Conflict Intersections) for improved safety now that the 2014 project is complete.

Hwy 169 intersection designsflood mitigation overview map

Driving Graphics

Why Reduced Conflict Intersections?

Reduced Conflict Intersection. RCIs are intersections that decrease fatalities and injuries caused by broadside crashes on four-lane divided highways. In some parts of the country, RCIs are sometimes referred to as J-turns or RCUTs. Learn more about how they improve safety and how to drive them in the video below.

About this project

Summary of work

This project involves raising Hwy 169 and Hwy 22 one foot above the 100-year flood elevation to maintain traffic during high water events. When these highways were originally constructed in the early 1960’s, the Minnesota River high-water elevation was assumed at 751 and the roads were constructed accordingly. The actual 100-year flood elevation in this area ranges from about 756.0 to 756.6. View project overview map (PDF).

Key issues

  • Unsuitable soils in reconstruction areas
  • Impacts to 6(f) environmental properties of Seven Mile Creek and Riverside Park
  • Coordination with rehabilitation of Hwy 99 bridge over Minnesota River at Saint Peter
  • Management of traffic during construction and access to businesses during construction

Cost

Cost estimate (millions) 2014 2015 2016
Construction 10.7 2.5 22.6-26.7
Construction-related costs 1.1 0.15 1.6-1.9
Engineering 1.5 0.5 4.5-5.3
Right of way 0 0.05 0.1
Total $13.3 $3.2 $28.8-$34