The I-270 North Design Build Project is the next step toward improvements along Interstate 270 North (I-270N) from McDonnell Boulevard to Bellefontaine Road. The Project will improve safety and reliability within the I-270 corridor, link communities, and enhance traffic operations so the public has a durable and maintainable transportation network.

Challenges within the corridor include safety, aging infrastructure, and minimal accessibility for pedestrians and bicyclists. These challenges are demonstrated through:

  • Traffic volumes: I-270 is one of the heaviest traveled interstates in Missouri;
  • 140,000 vehicles, of which 18% are heavy trucks, travel it daily
  • Limited pedestrian facilities
  • An aging infrastructure including bridges and pavement, originally constructed during the 60’s
  • The need to improve how people, vehicles and goods move throughout the interstate and on the outer road system


The I-270 North Project is the next step toward improvements along interstate 270 from I-70 on the west of the Riverview interchange. This follows the completed I-270 North Environmental Assessment (EA) that addressed impacts of safety and congestion, as well as accessibility and aging infrastructure, along I-270. The project goals include:

  • Reconstruct interchanges at North Lindbergh, Hanley/Graham, New Florissant, Washington/Elizabeth, West Florissant, New Halls Ferry, Old Halls Ferry, and Lewis and Clark
  • Additional driving lane in both directions on I-270 from North Lindbergh to Lewis and Clark
  • Improve accessibility for bicyclists and pedestrians with a multi-use path from Lindbergh to Breezy Point along Dunn, and from Hanley/Graham to Old Halls Ferry along Pershall
  • Improve safety with an updated outer road system that includes removal of all cross over slip ramps
  • Signal updates and replacements
  • New and replaced bridges


  1. Deliver the project by December 1, 2023 within the program budget of $278 million.
  2. Maximize reliability and safety while linking communities for all users.
  3. Provide a durable and maintainable transportation network making Interstate 270 the conduit for a prosperous region.
  4. Grow and utilize a diverse workforce.
  5. Minimize and mitigate impacts to customers through innovation.


I-270 North has a higher crash rate than comparable roads in our region. Reports show that both directions of I-270 have higher than average rates of severe crashes. They also indicate higher than average crash rates, with Eastbound I-270 showing an average crash rate 30% higher than the statewide average for interstates.

Some crashes can be attributed to traffic congestion, roadway design, and different vehicle travel speeds. An aging outer road system, developed many years ago to support much lower traffic volumes, also contributes to concerns about safety within the corridor.

Our project will improve mobility on the corridor and help reduce crashes related to traffic congestion. This project will make geometric improvements that address locations with high crash rates.

Traffic Congestion

I-270 North is one of the heaviest travelled roads in Missouri. On average more than 140,000 vehicles travel on I-270 North each day (Average Daily Traffic). The highway was originally constructed when traffic volumes were much lower during the 1960s. In addition, deteriorating pavement and bridges that were originally constructed during the 60’s, exist throughout the corridor.

The I-270 North Design Build Project will improve mobility on the mainline, at the interchanges, and on the outer roads. It aims to reduce traffic congestion faced by local users and interstate travelers.

Traffic congestion on I-270.
Traffic congestion on I-270.
Traffic congestion on I-270.

Deteriorating Infrastructure

I-270 is showing its age. Bridges and pavement are breaking down from many years of heavy traffic volumes. Traffic signals, signing, drainage structures, and lighting are all deteriorating. The existing infrastructure is breaking down and resulting in emergency maintenance repairs. This project will address deteriorated infrastructure and ultimately will result in fewer work zones along I-270 for years to come.

Image showing deteriorating infrastructure
Image showing deteriorating infrastructure
Deteriorating Infrastructure