In this Feb. 20, 2019, file photo, the ramp at the eastern end of I-395 in Brewer. Credit: Gabor Degre / BDN

Construction on a controversial $90 million project to extend Interstate 395 through Brewer, Holden and Eddington to connect it to Route 9 is scheduled to begin in September, according to the Maine Department of Transportation’s new three-year work plan released Monday.

The extension would start where I-395 currently ends at the Brewer-Holden town line and run six miles northeast until it reaches Route 9, also known as the Airline.

By price tag, it’s the largest of 2,180 individual work items the Department of Transportation has put on its plan for 202, 2022 and 2023. Those projects have a total value of $2.71 billion.

Both the value and number of projects are up slightly compared with the last three-year plan released in 2020 due to an increase in federal funding that offset a $30 million dip in money from the state’s Highway Fund. The plan also assumes $150 million in borrowing this year.

The Highway Fund has been challenged for years as a flat gas tax has become an increasingly outdated way to fund roads and bridges. It’s been especially challenged over the past year as travel has dropped in Maine and across the country during the coronavirus pandemic. A legislative panel formed to propose a long-term funding fix failed to propose a specific solution last year over thorny conversations about raising the gas tax.

The state has been planning the I-395 project for nearly two decades. It began acquiring properties in early 2019 to make way for the road, which is expected to affect dozens of property owners with land on or near the proposed route in Brewer, Holden and Eddington. The project would allow truck traffic from Down East Maine and Canada to access I-395 without using Route 46, which passes through Holden and Eddington, and Route 1A.

The state received a $25 million federal grant to pay for the project in 2018.

Aside from the I-395 extension, other projects in the three-year plan include bridge replacements in Old Town and Stillwater; continued work on the Acadia Gateway Center in Trenton; the replacement of two Maine State Ferry Service vessels; dredging in Searsport harbor; and rehabilitation work on U.S. Route 1 in Machias and East Machias.

To view and search the 2021 work plan, visit mainedot.gov.

BDN politics editor Mike Shepherd contributed to this report.