A local operating area consists of at least one local operating zone. The zone groups elements that can be worked locally. Zones can be disjoint, touch or even overlap. Adjacent zones can be independent, or can merge into a bigger zone to allow seamless shunting movement between them. Local control over the zones is taken in a given order, given by rank, e.g. 1-2-3. Handing back control is the inverse- operation, e.g. 3-2-1.