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Project Fact Sheet

PROJECT LOCATION:
U.S. Routes 2/7 (U.S. 2/7) in Colchester from Winooski town line north 1.05 miles to Sunderland Woods Road.

PROJECT OVERVIEW:
The Vermont Agency of Transportation (VTrans) is improving the roadway along the U.S. 2/7 corridor, in the vicinity of Interstate 89 (I-89) Exit 16, to enhance mobility and safety in Colchester, Vermont. The core of the project is to reconfigure the existing tight diamond interchange to a Diverging Diamond Interchange (DDI) at I-89 Exit 16.

Additional 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 such as sidewalks and shared-use paths.
Modernizing traffic signals at South Park Drive, I-89 Exit 16, Mountain View Drive, Hercules Drive, Rathe Road, and at Tigan Street in the City of Winooski.

WHAT IS A DDI?
A Diverging Diamond Interchange (DDI) is an innovative, modern interchange design that can relieve traffic congestion and improve safety for drivers, bicyclists, and pedestrians.

In a DDI, traffic crosses to the left side of the roadway allowing for ease of access to the interstate by eliminating difficult left turns. With traffic diverted to the left side of the roadway, vehicles making a left onto the interstate entrance ramps do not have to cross oncoming traffic, creating fewer conflict points. The reduction of conflict points reduces potential user collisions, thus improving safety and vehicle throughput. With left turn movements operating freely within the DDI, the traffic signals no longer require dedicated left turn phasing, improving overall traffic operations at the interchange. Additional benefits include reducing driver discomfort, fuel consumption, and lost time. Raised islands within the interchange create short crossing distances, which increase overall safety for non-motorized users such as pedestrians and bicyclists.

PROJECT COST:
In addition to the safety and operational benefits of the DDI, the construction of a DDI is cost effective. The DDI can be constructed utilizing the existing bridge structures eliminating the need to modify or replace them, reducing construction costs. The construction schedule of a DDI is much shorter than the construction of more common interchanges not only reducing overall cost, but also impacts to the traveling public.

CONSTRUCTION:
Construction of the Exit 16 DDI project is being completed in two phases under two separate contracts, executed sequentially. The first phase, which began in Winter 2023, consisted mainly of utility relocation, ledge removal, and retaining wall and drainage work and was completed in Fall 2023. The second phase of construction is anticipated to begin in Summer 2025 and will focus on the roadway construction, including the installation of the DDI, the addition of turning lanes, and the implementation of pedestrian and bicycle accommodations. The project is anticipated to be completed by Fall 2026.

During construction, weekly Construction Updates will be distributed to notify the public of construction activities and travel conditions for the following week. Project Updates and Traffic Alerts will be issued on an as-needed basis throughout the life of the project. Sign up to receive project updates on our website: www.Exit16DDI.vtransprojects.vermont.gov.

Contractor Phase 1: S.D. Ireland Brothers Corporation
Contractor Phase 2: TBD
VTrans Project Manager: Michael LaCroix
VTrans Resident Engineer: Chris Lavalette

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Proposed Changes to Route 2/7 at I-89 Exit 16 in Colchester

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