Center closed for reconstruction. D branch trains terminated at Park Street during peak hours and North Station at other times. All D branch trains resumed terminating at Government Center when it reopened on March 22, 2016. Work from 2018 to 2021 included a full modern signal system for the line between Beaconsfield and Riverside plus partial track replacements. Between October and December 2018, shuttle bus service replaced service between Brookline Hills and Reservoir every weekday evening and every weekend until after December 16. During 2019 and 2020, shuttle buses replaced service on 15 weekends and on all weeknights. The Fenway Portal project was completed on November 23, 2020. The track and signal work was completed in December 2021. Three nine-day closures of the whole D branch took place between September 24 and October 28, 2022, to allow for work including installation of a train protection system and track replacement between Eliot and Riverside. Accessibility Riverside station was rebuilt in the late 1990s, with raised platforms to provide accessible boarding on the then-under-construction Type 8 LRVs. Reservoir and Brookline Village were temporarily fitted with portable lifts for accessibility, with Brookline Hills added by 2003. Newton Centre, Reservoir, and Fenway were retrofitted with raised platforms around 2003. Woodland was rebuilt for accessibility in 2006, followed by Longwood and Brookline Village in 2009. Reconstruction of Brookline Hills station took place from September 2019 to January 2022 as part of the construction of an expansion of Brookline High School. Temporary work to make accessible was done in 2019–2020; a full reconstruction will begin in 2023. In 2019, the MBTA indicated that the remaining four non-accessible stops (Beaconsfield, Chestnut Hill, Eliot, and Waban) were "Tier I" accessibility priorities. A preliminary design contract for accessibility modifications at the four stations was issued in February 2021. Design was completed in late 2022, with construction planned to begin in mid-2023. Green Line Extension Original plans for the Green Line Extension called for the D branch to be extended through the rebuilt Lechmere station to Medford/Tufts station, with several intermediate stops. However, in April 2021, the MBTA indicated that the D branch would instead be extended to , with the E branch running to Medford/Tufts. The D and E branches were chosen for the extension because they serve the Longwood Medical Area; the D branch was assigned to the shorter Union Square Branch because its western leg is longer