Counties Impacted
St. Charles
Route Impacted
Work Type
Intersection Improvements
In Progress

Project Timeline

Design Plan
Fall 2021
Final Design
Summer 2022
Project Awarded
Fall 2022
In Progress
Construction begins
Spring 2023
Not Started
Expected construction completion
Summer 2024

What is the problem?

Traffic has increased in this area of St. Charles County as residential growth continues. As a result, drivers experience increasing congestion during the afternoon commute on Route 79.

What is the proposed solution?

MoDOT proposes the construction of a Continuous "Green T" (CGT) intersection at Route 79 and T. R. Hughes Boulevard.  This CGT intersection would allow northbound Route 79 traffic to never have to stop, greatly reducing afternoon traffic backups and helping to increase safety. 

A Continuous "Green T" intersection is a type of  three-legged intersection. In this specific case, Route 79 traffic flows north and south, and drivers on T.R. Hughes have the option to turn either north or south. When construction is complete, the northbound lane of Route 79  will be able to travel straight through the traffic signal without stopping. In addition, a lane will be added on southbound Route 79 from the T.R. Hughes intersection south to the start of the four-lane highway. 

There are at least three other Continuous "Green T" intersections in St. Charles County and they have also been built in several other states, including Florida, Nevada and Utah. These types of intersections are used in Australia, Canada and New Zealand. 

What are the anticipated impacts during construction?

Drivers may encounter narrowed lanes, periodic lane shifts and and off-peak lane closures during construction.

What changes can drivers expect as part of the project?

Drivers on northbound Route 79 will be able to proceed through the intersection without having to stop, reducing travel time and the likelihood of delays and congestion. Drivers on T.R. Hughes wishing to access southbound Route 79 and on T.R. Hughes Boulevard wishing to access northbound Route 79 will follow the traffic signal indications as they do today. 

What are the benefits of a Continuous Green T intersection?

Drivers can expect less delays while traveling in this intersection. By reducing the delay and backups, rear-end crashes typically are reduced, vehicles use less fuel passing through the intersection, and emissions are diminished.

How much does the project cost?

The estimated project cost is $2.1 million. MoDOT received $1.5 million in Federal Congestion Mitigation and Air Quality (CMAQ) funds for this project. 

An example of a Continuous Green T Intersection by the Virginia Department of Transportation
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What if I have questions?

Contact Photo
Andy Tuerck
Area Engineer, St. Charles County
Contact Info

Office: (314) 453-5046

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Chris's Portrait
Christopher Kelly
Project Manager
St. Louis District
Contact Info