I-89 Exit 16 Diverging Diamond Interchange

Target Construction: Spring 2020 - Fall 2021

The Vermont Agency of Transportation (VTrans) is improving roadway conditions along the U.S. Routes 2/7 corridor in the I-89 Exit 16 vicinity to improve mobility and safety.  The heart of the project is to reconfigure the existing tight diamond interchange to a Diverging Diamond Interchange (DDI).  Other improvements include:

  • Adding turn lanes at the Mountain View Drive, Hercules Drive and Rathe Road intersections.
  • Construction of dedicated pedestrian and shared pedestrian/bicycle facilities.
  • Modernizing traffic signals at South Park Drive, I-89 Exit 16, Mountain View Drive, Hercules Drive, Rathe Road and at Tigan Street in Winooski City.
A computer generated simulation of the DDI Southbound

A cgi rendering of the finished project depicting US 7 Southbound.

The DDI is an innovative traffic configuration where vehicular traffic crosses to the left side of the roadway (U.S. Routes 2/7) between the two signalized intersections with the on/off ramps. 

With traffic on the left side of the road, vehicles can enter and exit the freeway without needing to wait for a traffic signal to turn green creating a safer, more free-flowing, traffic condition. 

A computer generated simulation of the DDI Northbound

A cgi rendering of the finished project depicting US 7 Northbound.

The first DDI was constructed in Missouri in 2009.  DDIs are either constructed or planned in 46 states, with 98 in operation in 5 countries.  121 more DDIs are in advanced design or planning in the United States alone.


Project Milestones

Preliminary Plans

September 28, 2012


November 28, 2016

Right-of-Way Clear

Summer 2019

Bid Advertisement

Fall 2019

Contract Award

Winter 2020

Target Construction Schedule

Spring 2020 - Fall 2021

For more information on this project contact: 

VTrans Project Manager
Michael LaCroix