What do they do through Mississauga, Oakville, Burlington, Pickering, Oshawa, Whitby, etc etc etc etc
Mississauga: depends on where it is. They applied for, and received, permission to eliminate whistle blowing at the 7 crossings of the Oakville Sub many years ago. And while Mississauga has been trying to do that to as many level crossings as they can - particularly in residential areas - they haven't gotten them all yet.
Oakville: Had received permission to eliminate whistle blowing on their 5 level crossings of the Oakville Sub several years ago (and Burloak was done in concert with Burlington). They've also done that with all of the crossings on the Halton Sub within their borders.
Burlington: The only level crossing on the Oakville Sub is at Burloak. There are also a couple of level crossings on the Halton Sub, and the one furthest south - Mainway Dr. - has had the whistle blowing requirement eliminated. Burlington also seems to have an active program to grade separate its level crossings, with several being done in the past decade or two.
Pickering: Has only one level crossing on the Kingston Sub, Rodd Ave. Whistle blowing has been eliminated at this crossing for several years. There is one additional crossing on the CN York Sub, but it's in a rural area, and whistles have not been eliminated there. I don't have any information on the CP lines, unfortunately.
Oshawa: None of the crossings of the Kingston Sub in Oshawa have had their whistle blowing eliminated.
Whitby has no level crossings of the Kingston Sub, and I don't have information on the CP line.
Dan