Commuters have been warned to expect delays on the Yanchep and Mandurah train lines. Transperth posted on social media on ...

Test trains started running on Perth's new $A 1.4bn ($US 840m) 17.5km Thornlie - Cockburn commuter line on January 20.

More than a decade after it was first floated, the long-awaited Ellenbrook rail line opened on Sunday morning, with the promise of shorter commute times for people in Perth's north-eastern suburbs.

The government says it will enter negotiations to reverse the privatisation of the state's freight rail network, but grain farmers say the damage has already been done.