snow "plows"
If you can find any old pictures, you will find that the first snow plows had large V-shaped blades, like an agricultural plow [plough]. I suppose that on the narrower roads before WWII, they could run the plow down the middle and it would throw up the snow to both sides, clearing the whole road. With the wider roads now common, you need at least 2, sometimes 4 trucks with the rectangular flat blades running side by side to clear the whole width of a road at one go.