The MRA contains the entirety of the state's electrified rail network (save for the isolated Skitube Alpine Railway).

The MRA is owned by Transport Asset Holding Entity and maintained by Sydney Trains.

In preparation for the planned lease of the interstate and Hunter Valley networks to the Australian Rail Track Corporation (ARTC), the Transport Administration Act 1988 was amended in 2003 to define a "metropolitan rail area", to be managed by a new agency called RailCorp.

The northern section of the network extends 165 kilometres from Central and is electrified for its entire length.

[4] At its western extent, the MRA is bounded by the former station at Bowenfels, a few kilometres west of the town of Lithgow.