The province of British Columbia has not yet mandated that true winter tread tires be used during the winter months on all highways. However, one can only legally operate in the ice and snow using all season or summer tires if they are not traveling on posted highways or are carrying tire chains that are the appropriate size and type for the vehicle. This does restrict the use of all season tires in most areas of the province.
A posted highway is one that is marked with a sign advising motorists that they must use winter tread tires or carry chains once they have passed the sign. For the purposes of the sign, a winter tire is one that is advertised or represented by its manufacturer or a person in the business of selling tires to be a tire intended principally for winter use.
An all season tire is designed to be a compromise and operate in both summer and winter. It is not designed principally for winter use. Only those tires displaying the mountain and snowflake symbol on the sidewall are winter tires that fit this definition.
Should you choose not to follow the advice on the sign, police may prevent you from traveling further until you are in compliance. They may also choose to issue a traffic ticket that carries a penalty of $121 and 2 points, or about the price of a good winter tire or set of chains.