The Massachusetts Bay Transportation Authority (MBTA) in the US has awarded a contract to Keolis Commuter Services for the second phase work and the third phase preliminary design of the Franklin Line Double Track Project.

The $30m contract was cleared by the MBTA’s fiscal and management control board.

Keolis Commuter Services carried out the first phase of the project in collaboration with the MBTA’s Railroad Operations team. The project added an extra four miles of double track between the Walpole and Norfolk stations.

Work included the design, construction and commissioning of two new signal interlockings and the delivery of subgrade preparation work. Phase one is expected to conclude by the end of this year.

The new track is slated to be commissioned early next year.

Phase two is expected to begin after the completion of phase one. This will include adding three and a half miles of track from the Norfolk Station to Frank Street. The additional track is expected to increase the line’s resilience while reducing travel time from 45 minutes to 35 minutes.

Expected to conclude in December next year, phase two work also includes subgrade preparation, drainage improvement work and two interlockings, among others.

The preliminary design work for phase three will coincide with phase two. Phase three will focus on the four-mile track section between the Walpole and Norwood Central stations. After the design and construction of phase three, a double-track line will be built in Boston, along the line between the South and Franklin stations.

Earlier this month, the MBTA announced plans to refurbish the Natick Center Station on the Framingham/Worcester line of its commuter rail system.