TORONTO – Getting around the downtown core this long weekend will be a challenge after the TTC announced it would be closing a main section of the subway line to update the aging signal system.

The Yonge-University line will be shut down from Bloor to St. George stations on Saturday, Sunday and Monday. Shuttle buses will be running to accommodate riders.

However, the buses won’t run as far south as Union Station and will stop at King due to construction in the area. The TTC and the city are installing a second platform at Union.

“We’ll be running around 100 buses. There will be staff at all of the key locations — lots of customer service staff,” TTC CEO Andy Byford told CityNews on Friday.

“We’ll make sure we get everyone where they want to go this Thanksgiving weekend.”

The closure was previously scheduled for Oct. 19-20. The subway will now be running on those days after the repairs were pushed ahead.

Over the next five years, the TTC is upgrading its signal system, Byford said.

“From Finch all the way up to Vaughan, we are replacing 60-year-old signals … we’re plagued by far too many signal failures,” he said.

The signals won’t be replaced on a light-by-light basis, he said. Instead, the entire system will be replaced by a state-of-the-art grid in phases. The U-line is the most difficult, but Byford said there is a bright side.

“The new system will keep us good for another 40 years — and we’ll be able to run more trains safely, closer together. With more trains we’ll have more capacity and less crowding.”

Full subway service will resume on Tuesday at 6 a.m.