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 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

9/17/2026

Traffic Alert - The Exit 16 DDI Is Now Operational; New Traffic Patterns Are In Effect

The Exit 16 DDI Is Now Operational; New Traffic Patterns Are In Effect

DATE: Thursday, September 17, 2026

The new Diverging Diamond Interchange (DDI) is now open! Traffic on U.S. Route 2/7 (U.S. 2/7) at the I-89 Exit 16 Interchange in Colchester has transitioned to the new traffic pattern.

Time lapse photo of the Exit 16 Diverging Diamond Interchange in action.

Photo courtesy of Vermont Agency of Transportation Traffic Design Engineer Josh Bloomer.

The new traffic pattern briefly shifts vehicles to the left side of the roadway as they travel through the interchange, allowing drivers turning left onto interstate entrance ramps to do so without crossing oncoming traffic. Once vehicle travel through the interchange, traffic will return to the right side of the roadway. Traffic signals will control both crossover points. To learn more about how to navigate the interchange, please review the information below.

Drivers should stay alert, slow down, and pay close attention to roadway markings, signage, traffic signals, and traffic control personnel as construction activities continue and motorists become accustomed to the new traffic patterns.

Drivers may notice longer holds on U.S. 2/7 northbound at South Park Drive and U.S. 2/7 southbound at Mountain View Drive than they experienced before the DDI opened. Those holds are intentional and are designed to regulate traffic entering the interchange, balance traffic demand from all directions, and support efficient operations throughout the Exit 16 area. The goal is not to prioritize one roadway or movement over another, but to manage traffic across the entire interchange and U.S. 2/7 corridor as efficiently as possible overall. Motorists should also expect an adjustment period as drivers become familiar with the new traffic pattern. In addition, ongoing construction activities, including periodic lane closures and traffic restrictions, may result in temporary increases in congestion during work hours as the project continues toward completion in the summer of 2027.

10/9/2026

Weekly Construction Update - Friday, October 9, 2026

SPECIAL NOTICE: Crews will be off site starting at noon on Friday, October 9, in observance of Indigenous Peoples’ Day, and will return on Monday, October 12, at 9 p.m.

TRAFFIC IMPACT AND DURATION: Nightly, starting the night of Monday, October 12, through the morning of Friday, October 16, between 9 p.m. and 6 a.m., unless otherwise noted:

Monday and Wednesday night, the Interstate 89 (I-89) South off-ramp and I-89 North on-ramp will be fully closed from 9 p.m. to 6 a.m. Traffic will be detoured to Exit 17. The outer most lane on the west side of U.S. Route 2/7 (U.S. 2/7) between the interstate ramps will be closed. Two-way traffic will be maintained.
Tuesday and Thursday night, the I-89 South on-ramp and I-89 North off-ramp will be fully closed from 9 p.m. to 6 a.m. Traffic will be detoured to Exit 17. The outer most lane on the east side of U.S. 2/7 between the interstate ramps will be closed. Two-way traffic will be maintained.
Wednesday night, the outer most lane on the east side of U.S. 2/7 between the interstate ramps will also be closed. Two-way traffic will be maintained.

Daily, starting the morning of Tuesday, October 13, through the afternoon on Friday, October 16, between 9 a.m. and 3 p.m. unless otherwise noted:

The outer most lane on the west side of U.S. 2/7 between Whitcomb Street and the I-89 South off-ramp will be closed. Two-way traffic will be maintained.
The outer most lane on the east side of U.S. 2/7 between the interstate ramps will be closed. Two-way traffic will be maintained.
Short stoppages of less than 10 minutes will be in effect at the intersections of U.S. 2/7 at Mountain View Drive, Hercules Drive, and Rathe Road, starting at the U.S. 2/7 and Mountain View Drive intersection and working north. Traffic will be maintained in all directions by flaggers.

CONSTRUCTION ACTIVITIES: Nighttime work will take place between 9 p.m. and 6 a.m., starting the evening of Monday, October 12, through the morning on Friday, October 16. Throughout the week, crews will be installing the splitter islands on the interstate ramps within the Exit 16 interchange, under full ramp closures with detours to Exit 17 and lane closures. Additionally, crews will be removing overhead signage from the overpass bridges.

Daytime work will take place between 7 a.m. and 3 p.m., starting the morning of Tuesday, October 13, through the afternoon on Friday, October 16. Throughout the week, crews will be installing traffic signal equipment at the intersections of U.S. 2/7 at Mountain View Drive, Hercules Drive, and Rathe Road, starting at Mountain View Drive and working north, under short traffic stoppages. Additionally, crews will conduct preparatory work for future sidewalk installation along the west side of U.S. 2/7 between Whitcomb Street and the I-89 South off-ramp, and repairs to the eastern piers on the I-89 overpass bridges under single lane closures.

10/2/2026

Weekly Construction Update - Friday, October 2, 2026

REMINDER: Traffic at the Interstate 89 (I-89) Exit 16 Interchange in Colchester has permanently transitioned to the new Diverging Diamond Interchange traffic pattern on U.S. Route 2/7 (U.S. 2/7).

Motorists should remain alert and use caution while traveling through the area. Please slow down, follow roadway markings and signage, obey traffic signals, and watch for traffic control personnel as construction activities continue and drivers acclimate to the new interchange configuration. To learn more about DDIs and how to navigate them, visit the project website.

TRAFFIC IMPACT AND DURATION: Daily, starting the morning of Monday, October 5, through the afternoon on Friday, October 9, between 9 a.m. and 3 p.m. unless otherwise noted:

Lane closures along either side of U.S. 2/7 between South Park Drive and Mountain View Drive. Two-way traffic will be maintained. The traffic signals within the interchange will continue to be operational and control crossover traffic.

CONSTRUCTION ACTIVITIES: Daytime work will take place between 7 a.m. and 3 p.m., starting the morning of Monday, October 5, through the afternoon on Friday, October 9. Throughout the week, crews will continue installing the center islands along U.S. 2/7 and the splitter islands on the interstate ramps within the Exit 16 Diverging Diamond Interchange under lane closures. Crews will also adjust roadway structures and construct sidewalk in this area. Additional repair work will continue on the I-89 overpass bridge piers between the I-89 North and South ramps. This work will take place off the roadway.

9/25/2026

Weekly Construction Update - Friday, September 25, 2026

SPECIAL ANNOUNCEMENT: Traffic was transitioned to the new Diverging Diamond Interchange at the Interstate 89 (I-89) Exit 16 interchange in Colchester on Thursday, September 17. The new traffic pattern is now permanently in effect on U.S. Route 2/7 (U.S. 2/7).

TRAFFIC IMPACT AND DURATION: Daily, starting the morning of Monday, September 28, through the afternoon on Friday, October 2, between 9 a.m. and 3 p.m. unless otherwise noted:

Lane closures along either side of U.S. 2/7 between South Park Drive and Mountain View Drive. Two-way traffic will be maintained. The traffic signals within the interchange will continue to be operational and control crossover traffic.

CONSTRUCTION ACTIVITIES: Daytime work will take place between 7 a.m. and 3 p.m., starting the morning of Monday, September 28, through the afternoon on Friday, October 2. Throughout the week, crews will work to install the center islands along U.S. 2/7 and the splitter islands on the interstate ramps within the Exit 16 Diverging Diamond Interchange under lane closures. Additional repair work will continue on the I-89 overpass bridge piers between the I-89 North and South ramps. This work will take place off the roadway.

9/18/2026

Weekly Construction Update - Friday, September 18, 2026

SPECIAL ANNOUNCEMENT: The new Diverging Diamond Interchange (DDI) is now open! Traffic on U.S. Route 2/7 (U.S. 2/7) at the I-89 Exit 16 Interchange in Colchester has transitioned to the new traffic pattern. Drivers should stay alert, slow down, and pay close attention to roadway markings, signage, traffic signals, and traffic control personnel as construction activities continue and motorists become accustomed to the new traffic pattern. To learn more about DDIs and how to navigate them, visit the project website.

TRAFFIC IMPACT AND DURATION: Daily, starting the morning of Monday, September 21, through the afternoon on Friday, September 25, between 9 a.m. and 3 p.m. unless otherwise noted:

Lane closures along either side of U.S. 2/7 between South Park Drive and Mountain View Drive. Two-way traffic will be maintained. The traffic signals within the interchange will continue to be operational and control crossover traffic.
Periodic lane closures controlled by flaggers at the intersection of Tigan Street and U.S. 2/7. Traffic will be maintained in all directions.

CONSTRUCTION ACTIVITIES: Daytime work will take place between 7 a.m. and 3 p.m., starting the morning of Monday, September 21, through the afternoon on Friday, September 25. Throughout the week, crews will be working to install the center islands along U.S. 2/7 and the splitter islands on the interstate ramps within the Exit 16 Diverging Diamond Interchange. Crews will be installing temporary traffic signals at the intersection of Tigan Street and U.S. 2/7.