Mystic — While it's still in the early stages, the state Department of Transportation is proposing what Groton Public Works Director Greg Hanover considers “major intersection improvements” at the Interstate 95 north and south exit and entrance ramps with Allyn Street at Exit 89.

“The plan is to realign the entrance and exits at Allyn Street and install traffic signals at these locations as well as at Sandy Hollow Road,” a town document states.

The project is in the conceptual phase, and funding has not been allocated for it, but DOT representatives gave an overview of the project at this past week’s Town Council Committee of the Whole meeting to get initial feedback from the council.

Once the project is initiated, it would take two to three years for the design phase, said Marissa Pfaffinger, a DOT project manager. There will be public involvement and a public informational meeting as part of the design phase.

Pfaffinger said the purpose of the project is to address some of the operational and safety concerns, particularly at the northbound off-ramp where traffic backs up close to the exit.

In the three years between Jan. 1, 2018, and Dec. 30, 2020, there were 50 crashes in the area: 13 on the I-95 southbound ramps, 32 on the northbound ramps and five at the Sandy Hollow Road intersection, according to project engineer Emin Basic.

The concept to improve the interchange originally was proposed as part of a 2004 study of the east corridor of I-95 from New Haven to the Rhode Island border, Pfaffinger said.

A larger project for pavement and safety operational improvements on the main line started in the late 2000s but didn't advance to the construction phase due to funding and time limitations, she said. However, the design process did recognize the standalone benefits of improving the interchange.

DOT's Highway Management Unit began revisiting the idea last year and reviewing and updating some of the information and now has a concept in place, she said.

Pfaffinger said the potential for the redevelopment of the Mystic Education Center in the future did not factor into the decision to look at the exit, but the DOT is aware of it. She said DOT is incorporating the potential for future higher volume projections, including from a possible development, in its planning.

DOT estimates the project will cost $5 million and is expected to be funded with 80% federal funds and 20% state funds.

In addition to putting signals at the intersections, DOT is calling for further improvements.

For the I-95 southbound ramps and Allyn Street, DOT also proposes adding exclusive turn lanes on all approaches, removing the yield right turn onto I-95 southbound, and incorporating a minimum of a 4-foot shoulder throughout the eastern edge of Allyn Street.

For the northbound ramps and Allyn Street, DOT is proposing "minor geometric revisions" to the I-95 off-ramp and on-ramp and adding exclusive turn lanes to access the northbound on-ramp from Allyn Street.

For Allyn Street and Sandy Hollow Road, DOT is planning to improve the existing cross-section with minimal widening along the eastern edge of Allyn Street.

DOT also is proposing to "close the existing gaps in the sidewalk network in the immediate vicinity of Sandy Hollow Road."

At Tuesday's meeting, town councilors asked questions and offered initial feedback. The council plans to send a letter to DOT in support of the project concept.

k.drelich@theday.com