Québec has three thaw zones, in which the start and end of the load restriction periods are slightly lagged over time. This division of Québec’s territory into three zones was established by accounting for the geographical realities, the usual frost depth and the thaw trends in the different regions, the spring weather conditions and the traffic of heavy vehicles in the east-west axis.
Detailed map of thaw zones (6 MB)
Zone 1 includes the Québec territory located south of the following demarcation line, hereinafter referred to as the "demarcation line between zones 1 and 2.
From the intersection point of the centre line of the Ottawa River (Québec-Ontario border):
Zone 2 includes Îles-de-la-Madeleine and the Québec territory contained between the "demarcation line between zones 1 and 2" heretofore described and the following line, hereinafter referred to as the "demarcation line between zones 2 and 3".
From the intersection point of the parallel of latitude 48° 00’ north and the Ontario border:
Zone 3 includes the Québec territory located north of the "demarcation line between zones 2 and 3" heretofore described.
© Gouvernement du Québec, 2017