Who has to do what (and when do they have to do it) after it snows?

Your street hasn't been plowed and the sidewalk next door hasn't been shovelled.

Whose responsibility is it?

Roads:

According to the City of Windsor, there are 21 "main routes" that take snow plow priority after the fluffy stuff falls, including E.C. Row Expressway, Transit Windsor routes and emergency routes. 

Once snow accumulation has reached about five centimetres, the plows come out — but salt trucks should have been out before then. 

Salt begins to lose its effectiveness at below –12 C during a snowfall - City of Windsor

Those main routes cost about $12,000 an hour to maintain during a normal workday. 

Once the main routes have been cleared, streets near schools come next, followed by intersections if the City deems them necessary.

Residential streets are only plowed when there's been more than 10 cm of snowfall — and then only after the main routes are done. 

Sidewalks:

Residential home owners or tenants are required to clear snow off the sidewalks within 12 hours of the snowfall ending. 

Commercial property owners have four hours to clear their walks following snowfalls during the day or four hours after sunrise if snow fell overnight. 

If a plow pushes snow back onto the sidewalk, too bad. You get four more hours to clear the way.

If you don't shovel your residential sidewalk, a by-law officer can issue a ticket of $125.

Corporations can't be given a ticket, but can be taken to court through a summons. A justice of peace can then determine a fine for the infraction which can't be more than $5000. 

Bus stops:

Priority bus stops (identified by Transit Windsor) are cleared if the snowfall accumulation is more than 15 cm and once the roads are done.