Green Line to be shut between BC and Kenmore for 12 days for track work and installation of system to keep trolleys from slamming into each other

The MBTA said today the B Line will be shut between BC and Kenmore starting Monday "to conduct much needed track upgrades while also installing Green Line Train Protection System equipment across the system."

Shuttle buses will replace trolleys through July 1, the T says.

The announcement comes one day after the Federal Transit Administration gave the MBTA 30 days to come up with a series of plans to improve safety and almost a year after a driver crashed his trolley into the back of another on the B Line, causing multiple injuries.

The train-protection system includes a series of sensors along the tracks and equipment on the trolleys in a system designed to first warn drivers if they are going too fast or have blown past a red signal, then to stop the trolley if the driver doesn't. Initially planned for 2025 completion, the T now says it hopes to have the system working by the end of 2023.

The construction work will also include track work at three locations along the B Line:

A majority of construction efforts will occur at Linden Street in Allston, the Washington Street Crossover in Brighton, and the Cardinal Crossover located near Boston College. Crews will replace special track work as well as doing full-depth track reconstruction creating a safer, more dependable ride for B Branch riders. This closure is one of four that will be taking place across the Green Line this year. In completing just one 12-day closure, the Green Line Transformation team saves six months of weekend diversions.