LEOMINSTER – Preliminary design of the Twin Cities Rail Trail will be aired at a public hearing at 6:30 p.m. Wednesday at the Hilton Doubletree Hotel, 99 Erdman Way.

The hearing is the next step for a $20 million project started more than 15 years ago to connect downtown Fitchburg and Leominster with a 4.5-mile bicycle and pedestrian trail.

Before the hearing, starting at 6 p.m., people can look over the plans and meet the engineering team.

The state Department of Transportation expects to seek construction bids early next year, said Tom Skwierawski of Fitchburg’s community development office. Amy LeBlanc, senior project manager in that office, said final designs are to be submitted by May, with Phase 1 construction to start in spring 2020.

The trail will run along an abandoned railroad corridor from Mechanic Street in Leominster, over the Nashua River in downtown Fitchburg, to the MART intermodal transportation center in Fitchburg, according to MassDOT. It will intersect with 15 roads and driveways, according to MassDOT.

The first phase will go roughly from High Street in Leominster to the Nashua River in downtown Fitchburg. A second phase will extend the trail to the Fitchburg train and bus station, and on the other end to downtown Leominster.

“We are incredibly excited to see this project through to fruition,” Mr. Skwierawski said. “It has been the result of decades of effort from dozens of officials at the local, state and federal level. Projects like this can take a long time to happen and we are fortunate to be in this position to see it through to the finish line.”

He said studies show such projects improve residents’ quality of life and their property values.

Leominster Mayor Dean J. Mazzarella said the state is still “working on few spots” along the trail that need bridges.

“But that is no reason not to get started on Phase 1,” he said. “It is really going to be a boost. It will go through Doyle Field into downtown and Carter Park. ... We’re really excited.”

Ms. LeBlanc said MassDOT has committed $18 million in construction funds for the project, and construction is expected to take about two years. The state Executive Office of Environmental Affairs is providing around $2 million to fund the design, she said.

In 2017, the main body of the trail – about 3.8 miles of former rail corridor - was purchased from CSX Transportation for $2.8 million, with most of the money coming from MassDOT and the Federal Highway Administration. EOEEA provided $140,000, Leominster funded $342,000, and Fitchburg funded $87,000 through Community Development Block Grant funds.

“Phase 2 will be put out to bid while Phase 1 is being constructed,” Mr. Skwierawski said.