Member for Groom Ian Macfarlane told The Gatton Star there was only a possibility of the bypass tapering down to one lane on the "western side" of the Toowoomba Range crossing.

"That's part of the proposal but the Commonwealth wants a discussion with the state about we can get best value for money, so there are a couple of issues to be resolved," he said.

"There is the size of the tunnel, whether or not it can take fuel and explosives to keep them out of Toowoomba, whether or not there are three or four lanes going to the west, on the Charlton side of the range."

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