There has been a further delay to the re-opening of the Trans-Australia Railway.
Flooding in a key section of the line across the Nullarbor between Kalgoorlie and Rawlinna in WA has been slow to recede.
As a result, the freight train network remains at a standstill.
"Due to persistent water levels at one location, reopening of the rail line will not occur before Wednesday next week," Australian Rail Track Corporation said yesterday.
ARTC had hoped the line could be re-opened on Sunday after being closed back on March 11.
Some regions in the arid south-east of WA received their yearly rainfall in just a few days earlier in the month flooding inland areas and closing transport routes.
ARTC says it is working with specialist consultants, technical experts and crews hoping to provide a more accurate assessment of a possible re-opening date soon.
Triple road trains up to 53.5 metres in length have been approved to help solve the freight crisis across the Nullarbor.
Trucks have been moving across the re-opened Eyre Highway for almost a week now from South Australia to WA but the Trans-Australia Railway remains shut.
The rail network carries the bulk of food and other essential supplies into WA.
The National Heavy Vehicle Regulator late last week temporarily approved the crossing of the triple-length road trains over the Nullarbor until the rail network can be repaired.
NHVR chief operations officer Paul Salvati said the notices give consent to increased access for road trains up to 53.5 metres, between Port Augusta in SA and the WA border, and then internally into WA.
Mr Salvati said the notice would provide heavy vehicle drivers and operators with increased flexibility and expedited access to critical routes, facilitating the efficient transport of essential supplies and emergency relief for communities cut off by flooding.
"Truckies have had to take huge detours to reach their destination due to this flooding, and the NHVR recognises the importance of delivering essential items to the affected communities," he said.
"However, we are also urging drivers to exercise caution when travelling through these conditions, prioritising safety above all else.
"Due to the heightened risk and uncertainty, the NHVR will be proactively patrolling the region to ensure all heavy vehicle drivers are travelling safely."
The NHVR has powers to permit the triple trailers "to allow increased freight capacity on alternative road networks during a period when regular rail and road freight routes are cut by natural disaster".