WAFarmers says the report, Maintaining the State Road Network, highlights glaring deficiencies in the State Government’s management of the State Road Network which will take up to $800 million to fix.

WAFarmers transport spokesman, Colin Nicholl, said the report also reinforces WAFarmers calls on the Government to commit to repairing the State's narrow gauge rail network as a matter of urgency.

"With the recent closure of four regional rail lines, the number of trucks hauling grain is likely to quadruple, immediately placing lives in danger on a now proven defective road network," Mr Nicholl said.

"The Government can no longer sit on its hands playing bluff poker with the lives of regional West Australians.

"This report is an indictment on the mismanagement of the States road network by successive State Governments."

According to WAFarmers, among the Auditor's many findings are:

• The average age of the road network is steadily increasing, with nearly one third of the network having now reached the end of its design life.

• Roads are at increased risk of structural failure because levels of planned maintenance have declined over the past ten years.

• Addressing the overdue planned maintenance will be expensive and effectively targeting any restoration will be difficult for Main Roads due to a lack of some key information about the condition of the road network.

• The estimated cost of eliminating overdue maintenance may exceed $800 million.

"This Report highlights that the Governments ‘Plan B’ of using road instead of rail to transport grain is not economical or socially acceptable," Mr Nicholl said.

He said the Government needs to immediately break the current stalemate which is going to see massively increased truck movements on road and take responsibility for the safety of motorists in regional WA.

"Regional Western Australians are not interested in political posturing and pointing the finger of blame, they just want the problem fixed and the Government has a responsibility to do so," he said.