Thousands of runners are gearing up for the annual GoodLife Fitness Toronto Marathon featuring a full marathon, half marathon, 10K run, 5K run and 5K walk.
Meanwhile non-marathon drivers will be gearing up for congestion in the heart of the city.
Closures affect areas from North York to Ontario Place.
Starting at 6:00 a.m. a major closure will be Yonge Street from Finch Avenue to Davenport Road.
Some Gardiner Expressway and Don Valley Parkway ramps will be closed from 7 a.m. to 3 p.m. including:
Gardiner eastbound ramp to Jarvis Street
Gardiner ramp to northbound Spadina
Spadina ramp to the westbound Gardiner Expressway
Don Valley Parkway to Bayview/Bloor ramp
Lane restrictions will include the area bounded by Bayview Avenue, South Kingsway, Lake Shore Boulevard and Finch Avenue.