By the end of 2022, an idea in the works for nearly two decades to build a multipurpose trail connecting downtown Fitchburg and downtown Leominster could be complete.

That idea brought more than 100 people to the DoubleTree by Hilton Hotel in Leominster Wednesday, March 13 for a public hearing sponsored by the Massachusetts Department of Transportation.

The trail will be known as the Twin Cities Rail Trail. It will stretch 4.7 miles, starting at Mechanic Street in downtown Leominster and ending at the MART Intermodal Transportation Center in downtown Fitchburg.

It is known as a rail trail because it would follow the path of a former railroad — in this case, the decommissioned Fitchburg & Worcester Railroad line that later was owned by the CSX Corporation.

“The purpose of this Project is to provide safer and improved transportation access for bicycle users and pedestrians,” stated a fact sheet on the Twin Cities Rail Trail distributed at last week’s hearing. “This project seeks to accomplish this through the construction of a shared-use trail facility for bicycle and pedestrian users via the former railroad corridor, which connects the central business districts of Leominster and Fitchburg.

“As envisioned,” it added, “this regional trail will connect areas of cultural, economic, social, and natural significance along the multi-community corridor and provide a non-motorized transportation and recreational alternative for people of all ages and abilities.”

The 12-foot-wide paved path would pass by areas like the Doyle Conservation Area, Leominster Hospital, Watertower Plaza, Doyle Field, Pine Grove Cemetery and Carter Park in Leominster, Fitchburg Municipal Airport, and the South Fitchburg Playground.

The trail would be completed in two phases, according to John Hendrickson from project designer Stantec. The first phase would be from Carter Park to 1st Street in Fitchburg, and the second phase would include the sections from Carter Park to Mechanic Street in Leominster, and 1st Street to downtown Fitchburg.

The Twin Cities Rail Trail will cost about $18 million, which includes funds from the federal, state and local governments. Money from the cities of Fitchburg and Leominster would be used to acquire the land, as well as any property easements needed for the project.

Last week’s hearing marked the 25 percent design milestone for the Twin Cities Rail Trail. A timeline provided by MassDOT stated that the completed design would be submitted by April 30. Bid advertisements for Phase 1 would be issued in September, and construction would begin in the spring of 2020. Phase 1 would include the installation of arched bridges over the Hamilton Street Brook and Route 2 (the Route 2 bridge would replace the current pedestrian span near Exit 31).

The final design plans for Phase 2 would be submitted in the summer of 2020, with construction occurring in 2021 and 2022. Additional time is needed for Phase 2, according to Hendrickson, because the City of Leominster is in the process of buying the railroad bed from Carter Park to Mechanic Street from CSX, and so the bridges on the Fitchburg section of the trail (including a five-span bridge over the MBTA line near downtown) could be designed.

Public comments on the Twin Cities Rail Trail project are being accepted by MassDOT for the next few weeks. They may be submitted by mail to Patricia A. Leavenworth, P.E., Chief Engineer, MassDOT, 10 Park Plaza, Boston, MA 02116, Attention: Roadway Project Management, Project File No. 608193. Submissions postmarked no later than Wednesday, March 27 can, if requested, be included in the public hearing transcript.