The older suburbs of Melbourne were once criss-crossed with back laneways for the discreet collection of...errr...nightsoil by a contractor with a horse and cart.
With the advent of the sewer system, some lanes became disused, or used for illegal activities. Many of them have since been sub-divided and sold to adjoining landowners.
In this suburb, street frontages are very small, so the lanes are maintained to allow vehicle access into the back yard if the property owner wishes. So where there was once an outhouse, there is now a small garage or carport.