The State Opposition has accused the Transport Minister, Troy Buswell, of secrecy over a grain export deal in the South West.
The Government has given in-principle support for agribusiness, Bunge, to transport up to 500,000 tonnes of grain per annum through Bunbury Port from 2014.
Labor's transport spokesman, Ken Travers, says this would see an additional 1,000 trucks a week travelling along the Coalfields Highway.
The highway runs from Wagin in the Wheatbelt through Collie to the South West Highway.
Mr Travers says Mr Buswell has not told the public what routes the trucks will take and what impact there will be on local roads.
"They know it is going to be dramatic, it is going to actually put lives at risk," he said.
"The volume of trucks that we're putting onto roads that simply are not able to handle them is dangerous and it is just unacceptable that we keep that sort of information secret from the public.
"The impacts on a local community are not confident commercial negotiations, they are issues that should be made public." Mr Buswell says the Government has nothing to hide.
He says the company is yet to finalise contracts and once the truck routes are known, they will be made public.
"We're more than happy to share those with the public when it comes to the use of our roads," he said.
"Of course the Government is working with them [the company] so we can understand the impact of that transport effort.
"We'll make sure that the process is monitored and managed and if road upgrades are required as part of that then we'll look at how we go about funding that."