A protected bike lane project that allegedly started construction a year ago is finally showing some visible signs of progress.
Boston's Massachusetts Avenue Better Bike Project will create a two-way protected bikeway along the western curb of Massachusetts Avenue from Melnea Cass Boulevard in Roxbury to Columbia Road in Dorchester.

Planning for the project began in the fall of 2019, and there had been little visible progress on the project until this month, when construction crews started building several new bus boarding islands along the western curb of the street (see photos above and below).

In between these islands, the city plans to install modular concrete curbs to protect the new two-way bicycle path from motor vehicle traffic.
Work appears to be moving from south to north; as of Thursday afternoon, excavators were digging out asphalt for a third bus stop and crosswalk at Allstate Road, near the South Bay Center strip mall.
When the project is complete, a new two-way, protected bicycle path will occupy the western edge of Massachusetts Avenue, providing a safer bicycle route between Everett Square in Dorchester and Melnea Cass Boulevard at the edge of the South End.
A few blocks to the north, work is continuing to build new protected bike lanes and improved crosswalks on Tremont Street, between Massachusetts Avenue and Interstate 90.
A few blocks of Tremont in the southwestern end of the project are nearly complete, like this intersection with Pembroke Street:

However, many blocks remain under active construction, so while it's tantalizingly close, it's not yet a great bike route between Roxbury and downtown Boston.
In the meantime, though, Tremont has already become much, much easier to cross on foot, and vehicle speeds feel like they're more reasonable, too. With the new median islands installed at most intersections, and ongoing construction at others, most of Tremont Street is now functioning as a two-lane street: no longer is it possible for bad drivers to swerve around slower or stopped vehicles, as they could in the street's former four-lane layout.