Roller?

My sister stayed over night and joined Louise and I for an early morning walk to Number 16 Beach for a coffee and then via the Peninsular Pantry for another coffee but unfortunately, it was too busy to stop. On the way we pasted a vacant block of land in a relatively suburban street and this piece of machinery was "parked" just near the road just where it has always been for the last 12 months. I wonder what it is for?