The Wheatbelt is facing more trucking hell with the crisis in the grain freight rail network spreading to a key line north of Perth.
The Tier 2 line has been downgraded to operate at half capacity and there are growing fears of more closures or partial closures for this season's harvest.
CBH will brief communities and shire councils on the likely impact next week. Even the best case scenario will see tens of thousands of extra truck movements on crumbing roads.
It is increasingly likely rail downgrades, section and line closures will impact on communities and road safety over a much bigger area than revealed so far, from Miling in the north to Narrogin in the south.
Concern has centred on Tier 3 lines - with leaseholder Brookfield Rail closing the Merredin to Trayning and Quairading to York routes. But the Tier 2 Miling to Bolgart line is on death row after its downgrade.
Brookfield has told CBH, which pays to cart grain on the rail network, the line will close within two years.
Nationals MLA Shane Love said it was an alarming development because in 2010 the State Government committed almost $190 million of taxpayers' money to ensure the future of Tier 1 and Tier 2 lines.
Mr Love said no money had been allocated to upgrade roads in his electorate in anticipation of extra road train movements.
He has written to Transport Minister Troy Buswell about the issue and is lobbying for details of the Government's controversial lease agreement with Brookfield to be made public.
"I think that with Tier 2 now under threat public interest demands there be an examination of the terms of that contract," Mr Love said.
"If taxpayers are being asked to invest to the extent that we have and growers are paying day-to-day access charges, we have a right to know exactly what the expectations are on us and what the expectations are on Brookfield."
An Auditor-General's report released this year was scathing of the Public Transport Authority's oversight of the lease. It revealed PTA advice that there was nothing to stop the tabling of the contract in Parliament.
CBH and Brookfield are poles apart on an agreement to keep remaining Tier 3 lines open, with grain growers weeks away from starting work in earnest on a bumper 13 million tonne harvest.
CBH logistics manager Andrew Mencshelyi said growers faced increased freight costs as a result of the Miling to Bolgart line downgrade. Districts on the line were expected to produce more than 370,000t this season and the downgrade would force much of it into road freight.
Brookfield Rail chief executive Paul Larsen said it would be inappropriate to respond to the claims while in confidential commercial negotiations with CBH.