What are the problems with the I-270 and Dorsett interchange presently?

The Interstate 270 and Dorsett interchange is congested due to heavy traffic utilizing the interchange.

 

Where are we now?

The Missouri Department of Transportation held a public meeting Wednesday, October 24, 2007 on the proposed I-270 and Dorsett Road interchange project.  MoDOT experts discussed planned interchange improvements for I-270 and Dorsett and what the local community and motorists can expect.  Residents also shared their opinions and provided input on two proposed design options for the interchange.

 

What is the proposed solution?

After presenting two alternatives at the public meeting, MoDOT is proposing to construct the interchange as a diverging diamond interchange (DDI).  Some of the advantages of a diverging diamond interchange include free turns for motorists, meaning vehicles don’t cross opposing traffic. Traffic models indicate this type of interchange works well with areas of heavy traffic, such as Dorsett Road.

The city of Maryland Heights will also be relocating Old Dorsett Road and Progress Parkway while this project is under construction.

The diverging diamond interchange is a new type of traffic solution, meeting the needs of intersection safety, increasing capacity and decreasing congestion.  The U.S. Department of Transportation Federal Highway Administration has more information about diverging diamond interchanges at the web site below.

http://www.tfhrc.gov/safety/pubs/07048/index.htm

The Missouri Department of Transportation is proposing to build a DDI at the interchange of Interstate 435 and Front Street in Kansas City. It would be the first DDI built in the United States.

 

Will this project close lanes of I-270 during construction?

No, MoDOT plans to keep all lanes of northbound and southbound I-270 open during construction.  Work will not begin on the project until the I-64 re-construction project is completed.

 

How much will this construction cost?

 

MoDOT is contributing $10 million towards the $30 million dollar cost for this project.  Other contributors include the city of Maryland Heights, St. Louis County and federal funds.  MoDOT’s portion of funding comes from an economic development fund earmarked especially for roadway improvements linked to community economic development. In this case, Edward Jones is pledging the addition of 500 new jobs.

 

Current project timeline

 

Public meeting   Oct 2007

Open for bids     June 2009

Work Awarded   July 2009

Construction begins Jan 2010

Construction Completion November 2011

 

Additional Information:

 

Proposed I-270 and Dorsett Road Interchange Project (1 page, 17.8 MB)

Overhead view animation of Diverging Diamond Interchange (9.09 MB)

Driver's view animation of Diverging Diamond Interchange (22.6 MB)

Who do I contact for more information?

 

Contact MoDOT Project Manager Lee Hilner at 1-888 ASK MODOT (275-6636) or e-mail Lee.Hillner@modot.mo.gov

Contact MoDOT Area Engineer Larry Welty at 1-888 ASK MODOT (275-6636) or e-mail Lawrence.Welty@modot.mo.gov

Contact MoDOT Community Relations Specialist Jack Wang at 1-888 ASK MODOT (275-6636) or e-mail Jack.Wang@modot.mo.gov