Emergency vehicles should be given right of way, everyone will know that and the Traffic Reglament, articles 67 and 68 confirms that. General rule is that you should move as far to the right as possible, or even bring your vehicle to a standstill if necessary.
But how to react exactly on motorways with more than one lane? Pictures below will explain.
One lane for each direction – both drivers should move as far to the right as possible.
Two lanes going in the same direction – driver in right hand lane should move as far to the right as possible, driver in left hand lane as far to the left as possible.
Three lanes going in the same direction – driver the right hand land and the middle lane should move to the right, driver in left hand lane to the left.