Starting Saturday, April 11, Metrolinx crews start three projects to improve train infrastructure in the Union Station rail corridor.

Crews are upgrading signals in the corridor between Bathurst and York Streets. They’re enclosing and installing cables and working on the foundation for the “bungalows” — the housing for signal and communications computers that control switches, crossings and other such controls, relaying information to and from the rail traffic control. They’re also insulating rail joints.

They work overnight from 8 p.m. Saturday, April 11 until 5 a.m. Sunday, April 12 and continuing overnight nightly. The crews must take tracks out of service to complete this work so they can only work on the project during off-peak times, when there is less train traffic. Nearby residents will notice activity from power tools (grinding, hammering and welding) and equipment moving during this time resulting in overnight noise.

Crews continue upgrading the signals overnight nightly until 5 a.m. April 18.

Other crews are installing caissons in the area of Lower Spadina Avenue and Front Street West. They start working from 7 until 10 p.m. Saturday, April 11 and continue nightly until further notice.

From 8 p.m. Saturday, April 12 until 5 a.m. Sunday, April 12, crews are also replacing the track ties between John Street and Union Station.