Lanes will be reduced on Queen Street between Bathurst Street and Spadina Avenue for watermain and road repairs from May 9 to October 8.
There will only be one lane in each direction with work to begin on the north side of Queen Street followed by the south side.
The city says pedestrians will still have access to businesses and residences during construction.
The 501/301 Queen route will divert both ways via Spadina Avenue, King Street West and Shaw Street.
Shuttle buses will run between Spadina and Shaw to help with service.