It reveals that Transurban would be compensated if it loses tolling revenue by closing traffic lanes on Citylink in order to build the tunnel. The payments would apply if the traffic disruptions were unforseen and had not been scheduled with Transurban. They could arise from planning approval delays, changes to the project's design or new laws affecting the road. If the road's builders CPB Contractors and John Holland are responsible for unforeseen CityLink disruptions, the joint venture would be slugged with the bill. This is designed to minimise unplanned impacts or extended delays to motorists. But the builders' bill is capped at an undisclosed amount, with the government to pay any outstanding fees. An independent auditor has been barred from calculating the compensation payments, the documents also show.