IIRC, this whole idea was based on a similar program from Winnipeg:
http://winnipeg.cityguide.ca/ellice-...7th-020468.php
Ellice will be hosting its 9th annual Ellice Street Festival next Sunday, June 7th from noon until 4:30pm. Streets from Langside to Sherbrook will be closed so that this great event can take place. There will be lots of face painting, magic, clowns, carnival, street hockey, basketball, BBQ and music by Billy Joe Green, Magnificent 7's, Coffieman, Hot Dogg.
http://osbornestreetfest.com/canadaday.htm
This year, Osborne Village will come alive for a day and a half, with the Street closing the evening of June 30th and all day July 1st. Over the Course of Winnipeg’s largest and longest running Canada Day Street Festival, with the assistance from Mother Nature, we shall see over 70,000 people through the festival site.
I don't know if these are the only ones, or how successful it is, or whether the closed roads are major routes.