Why does the Town place sand/salt on top of the snow and then plow?

In addition to providing some traction improvement, the reaction of the salt mixture with the snow creates a brine solution at the road surface.  This brine helps to break the bond between the snow/ice and the road and ultimately facilitates easier removal with winter operations equipment.  Generally, after the roads have received a treatment of sand/salt, the plow trucks are then outfitted with the front plow blades and dispatched to remove the “slushy” snow.  Since the plow blades ride slightly above the road surface, the mixture is not entirely plowed off the road.