Boston’s MBTA unveiled plans to accelerate infrastructure projects for several subway and commuter rail lines during calendar year 2020 to improve service, safety, and reliability on a faster timeline. The projects will include additional diversions of weekend service on all rapid transit lines and several commuter rail lines. In addition to several weekend diversions on the Green Line, the MBTA is planning for two one-month shutdowns on the Green Line — the C Branch in July and the E Branch in August.

The 2020 Infrastructure Acceleration Plan will deliver these projects eight years faster than originally planned, and will result in track replacement, upgraded intersections, and station improvements.

In 2019, the MBTA executed a plan to expedite projects for customers, delivering projects 2.2 years faster than originally planned across the Red, Orange, and Green Lines.

• Much of this work was completed through 10 weekend shutdowns on the Red and Orange Lines through the core of downtown Boston.

• During those shutdowns, the MBTA was able to accelerate improvements by expanding traditional work windows and increasing the number of work activities that took place.

• Throughout those weekends, the MBTA accommodated customers by increasing existing parallel service while also providing robust replacement service where feasible during the diversions.

In addition to the full-month C and E Branch shutdowns, as previously announced, the MBTA has scheduled an 11-month suspension of regular Green Line service between North Station and Lechmere starting in May 2020. During the closure, the T will accelerate efforts to strengthen the historic Lechmere Viaduct in coordination with the rebuilding of the elevated segment of track through East Cambridge and the realignment of the track to a new, relocated Lechmere Station, which is being completed as part of the project to extend the Green Line to Somerville and Medford.

• During diversions of regularly scheduled rail service, the MBTA takes steps to provide replacement service to ensure customers can reach their intended destinations.

• In certain cases, the MBTA increases the frequency of parallel services to accommodate customers displaced by a diversion.

• In other cases, the MBTA provides accessible shuttle buses — operated by the MBTA or a private carrier — that are specially designed to account for passenger travel patterns during these diversions.