I-70 Cave Springs to Fairgrounds
Design-Build

Project Description

This project will make interchange and outer road improvements along I-70 in St. Charles County, between Cave Springs Road and Fairgrounds, in order to make the corridor safer and more efficient. This section of I-70 is one of the busiest and oldest section of the interstate highway in Missouri. The increase in population due to residential and business expansion requires an improved traffic flow in the area.

The need for this project came from the I-70 Planning and Environmental Linkage Study (I-70 PEL) completed in 2018. More information about the process that study followed, along with the final report, can be found here. The I-70 Cave Springs to Fairgrounds Project falls in Sections 2 and 3.

Project Map

Corridor Issues

  • This section of I-70 is one of the oldest interstate highways in the country and busiest in Missouri. It was built in the 1950s and 1960s. The interchanges at Zumbehl and Cave Springs were built in the 1960s and modified in the 1980s Over the past five years, there have been approximately 3,000 crashes (significantly higher than comparable interstates).
  • The interchanges are congested and inefficient, sometimes even backing up onto the interstate. Specifically, the exits at Zumbehl and Cave Springs are so congested at rush hours that traffic backs up onto the highway.
  • The outer roads are not used effectively because they are discontinuous, putting more local traffic on the interstate.
  • The outer roads, whether due to traffic mitigation countermeasures such as restrictive islands or due to simply not existing yet, are discontinuous and inefficient, increasing traffic on the interstate for local trips. Example: NOR does not exist from Fairgrounds to Zumbehl. Crossing the highway, whether to continue on the cross street or to access the interstate or outer roads, is time consuming due to four or more signalized intersections and hundreds of conflict points.
  • MoDOT has tried different strategies to improve traffic flow in the interchanges such as modifying signal timing and installing a concrete island at Cave Springs which prevents WB traffic on SOR from going through or turning left – the only option is to turn right toward the highway
  • Bridges and roadways in this area need rehabilitation work – it is more efficient to do mobility improvements simultaneously with such rehabilitation work.
  • There are not many opportunities for pedestrians to safely cross the interstate in this section
Car traffic
  • We have tried different strategies to improve traffic flow in the interchanges such as modifying signal timing and installing a concrete island at Cave Springs which prevents WB traffic on SOR from going through or turning left – the only option is to turn right toward the highway
  • Bridges and roadways in this area need rehabilitation work – it is more efficient to do mobility improvements simultaneously with such rehabilitation work.
  • There are not many opportunities for pedestrians to safely cross the interstate in this section

Possible Alternatives to Fix Problems

MoDOT is using the Design-Build method to design and construct this project. A design will be selected as the best-value proposal after the confidential proposal development in 2021. For information on some strategies MoDOT has used historically here and elsewhere in the state to improve traffic flow, click here

Project Schedule

Complete

Letters of Interest

Complete

Project Advertisement

November 2, 2020

Complete

Industry Meeting/ RFQ Release

December 7, 2020

Complete

Virtual Public Open House

December 8, 2020
Click here to view a video from the open house.

Not Started

SOQ Shortlist

January 18, 2021

Not Started

RFP Released

February 5, 2021

Not Started

Proposals Due

TBD

Not Started

Award at MHTC Meeting

June 2021

Not Started

Construction Begins

TBD

Not Started

Construction Complete

TBD

Project Goals

  1. Maximize improvements within the program budget of $62 million.
  2. Improve safety and efficiency of the transportation network while supporting connectivity for the local community.
  3. Provide a durable and maintainable transportation infrastructure allowing for future expansion.
  4. Minimize impacts to the traveling public during construction while safely delivering the project by November 1, 2023.
  5. Deliver the project using a diverse workforce.

Funding Information

missouri dot logo St. Charles County logo
MoDOT & Federal Funding
$52 million
St. Charles County Cost Share
$10 million
Total: $62 million

Disadvantaged Business Enterprise (DBE) Goals

14% for construction activities

20% for professional service activities


Federal Workforce Diversity Goals

14.7% Minority

6.9% Female