Choose your speed according to conditions; weather & road. The speed limit applies to the best conditions. In winter, conditions are rarely so good that you can drive according to the speed limit.
Quickview of speed limits:
In populated areas, it's typically 50 km/h;
on thruways, it's often 60 km/h;
residential areas usually have a limit of 30 km/h;
and paved roads allow for speeds of up to 90 km/h.