Vermont’s First Diverging Diamond Interchange

The Vermont Agency of Transportation (VTrans) is improving the roadway along the U.S. Routes 2/7 (U.S. 2/7) corridor, in the vicinity of Interstate 89 (I-89) Exit 16, to enhance mobility and safety in Colchester, Vermont. The project area extends from in the Colchester-Winooski town line north for approximately 1 mile to just beyond the intersection of Sunderland Woods Road at U.S. 2/7. The core of the project is to reconfigure the existing tight diamond interchange to a Diverging Diamond Interchange at I-89 Exit 16.

Learn more about this and other improvements

Image of Interchange

Project Updates

Weekly Construction Update 3/31/2023

DATE: Friday, March 31, 2023


Crews will be onsite Monday through Friday between the hours of 6:00 a.m. and 3:00 p.m. Traffic impacts will be restricted to the hours of 6:00 a.m. and 3:00 p.m., Monday through Friday.

Starting Monday, April 3, and continuing through next week, crews will begin blasting activities behind the bridge piers on the west side of the interstate bridges over U.S. Route 2/7 (U.S. 2/7). This work will require the closure of the outermost southbound lane on U.S. 2/7 between the hours of 6:00 a.m. and 3:00 p.m. In addition, traffic will be temporarily impacted on U.S. 2/7 and Interstate 89 (I-89) as part of the blasting activities more specific information is provided below. These impacts will be restricted to the hours of 9:00 a.m. and 2:00 p.m., Monday through Friday.

On Friday, April 7, between the hours of 6:00 a.m. and 3:00 p.m., access to Highpoint Center (across from South Park Drive) will be reduced to one lane in each direction north of the existing median. Flaggers will be present to assist motorists.


Read more

Blasting Overview March 22, 2023

Blasting Activities

The Exit 16 DDI will be conducting drilling and blasting activities (blasting) to remove hard rock and ledge below the surface of the ground that cannot be removed using mechanical methods. Blasting is anticipated to begin the week of April 3rd and continue for approximately two months. The start of blasting activities is weather dependent.  Blasting will take place along U.S. Route 2/7 (U.S. 2/7) between South Park Drive and Mountain View Drive. Up to two blasting events will take place a day and will be restricted to weekdays, Monday through Friday (excluding holidays) between the hours of 9:00 AM and 2:00 PM, the exact time of each blast will vary.

Ledge has been located at depths as shallow as 4 feet beneath the roadway surface throughout the area. Blasting activities are required to facilitate the installation of the west side retaining wall off of the roadway behind the I-89 bridge pier (shown in red) and the relocation of underground utilities within U.S. 2/7 including the waterline (shown in blue) and electrical and telecommunication utility duct bank (shown in yellow). Portions of the waterline will be relocated to depths of over 12 feet beneath the roadway surface.

Read more

Construction Public Meeting Materials are NOW Available!

The Vermont Agency of Transportation (VTrans) held a Construction Public Meeting for the Exit 16 Diverging Diamond Interchange (DDI) Project on Thursday, January 12, 2023. The Construction Public Meeting included a presentation comprised of an overview of the project, the construction schedule and sequence, the anticipated impacts, and information about future blasting activities. A copy of the presentation can be found here or under presentations on the Documentary Library tab of the website!

Representatives from the project team, the contractor, S.D. Ireland Brothers Corp., and the blasting subcontractor, Maine Drilling & Blasting addressed comments and questions provided by attendees. A recording of the Construction Public Meeting can be found here or under presentations on the Documentary Library tab of the website!

Exit 16 DDI Winter Newsletter Released

No matter how you celebrate, the Exit 16 DDI Project Team would like to wish you and your loved ones a safe and happy holiday season!

The Winter 2022-2023 Exit 16 DDI Project Newsletter is now available. The newsletter includes project updates, winter travel safety tips and more! Check out the Winter 2022 Newsletter

Project Updates

Construction of the Exit 16 DDI project will be completed in two phases under two separate construction contracts which will be executed sequentially. The project has been approved for winter work and construction on the initial phase will begin as early as the last week of January 2023. Phase 1 construction will consist of utility relocation, waterline replacement, utility duct bank installation, retaining wall construction, and some ledge removal.

The construction public meeting will be held in early to mid January and including a presentation on the project overview, construction schedule and sequencing, the anticipated impacts, and information about future blasting activities with the opportunity to ask questions of the project team and contractor. Additional information including the exact time, date, and location will be shared in supplemental notices as the information becomes available.

Read more

Driving Animations

Experience Exit 16 DDI

Driving simulation traveling on US 2 West / 7 North through the DDI

Aerial view of the operating diverging diamond interchange at I-89 Exit 16

Driving simulation exiting I-89 onto US 2 East/7 South via Exit 16

Driving simulation traveling on US 2 East/7 South through the DDI

Driving simulation exiting I-89 onto US 2 West / 7 North via Exit 16