In the city of Calgary (where I do not live), homeowners are required to keep the walks in front of their house - ie, along the streets - clear of snow and ice. The walks ARE city property - but there are nowhere near enough resources to clear all the sidewalks in the city after a bad storm.

OT - in winter, the residential side streets get NO plowing at all...so the slowest speed zones in the city are filled with slippery grooves and ruts.