Sanral's public notice on the Winelands tolling project was unlawful because the national roads agency never took a proper board decision committing to the project, the Western Cape High Court heard on Friday.

Geoff Budlender, for the City of Cape Town, argued that the SA National Roads Agency Limited (Sanral) had been "ducking and diving" to conceal the absence of such a decision, as it rendered their case invalid.

He was presenting argument for an urgent interdict preventing Sanral from going ahead with the N1/N2 Winelands Toll Highway Project until a court reviewed the project's legality.

The city wants a court order forcing Sanral to provide certain documents it had requested on the decision-making process, to assist it in the review which is pending in the same court.

Judge Ashley Binns-Ward stated that the court and the city did not know what evidence Sanral would lead in the review. Budlender said this was precisely the case because Sanral did not want it to be known.

"There was no board decision," Budlender said, adding that therefore Sanral's declaration published in the Government Gazette in 2008 was unlawful.

He said a ruling calling a halt to the project pending the review would assuage most of the city's anxiety.

Binns-Ward said he would give a ruling on the application "sometime next week".

The city had argued the decision-making process on the toll project was flawed. It believed there was evidence to suggest the environmental minister at the time authorised the project based only on its environmental impact, not the socio-economic impact on the surrounding communities.

The toll project has been in the pipeline for nearly a decade. A record of decision was first issued in 2005, then re-issued by then minister of tourism and environmental affairs Marthinus van Schalkwyk in February 2008.

Chris Loxton SC, for Sanral, argued that the city was approaching the matter in an "upside down" manner. He said the socio-economic impact could only be considered once Sanral had authority to upgrade the roads, because only then could it determine how to fund the work.

The steps to be followed in this regard were to start concluding a concessionaire contract, calculate the total costs involved, and then see if it was feasible to collect the funding required through tolls alone or through co-contributions.

It has agreed to hold off on signing a concessionaire contract with its preferred bidder until June 1.

At present, Loxton said on Friday, the costs were unknown.

In court documents, Loxton said the decisions into which the city was demanding insight were not part of the current court proceedings.

Furthermore, he said, the city had failed to explain why the documents would be relevant.

He suggested the city was abusing the court process to obtain a document on which it could build an argument to block the toll road, because it did not support the user-pays principle on roads.

"The city appears to hold the view that it is entitled to conduct an inquiry spanning many years, to establish whether or not there is some document that will assist it in obstructing the implementation of the user-pays principle.

"It is submitted that it may not use a judicial review process to do so."

Sanral criticised the city for taking three years to institute legal proceedings.

The proposed concession route along the N1 extends from west of the R300 interchange through to Sandhills. The N2 portion of the proposed toll road concession extends from west of the R300 to Bot River.

According to a diagram on Sanral's website, 106 km of the N1 and 70 km of the N2 would be tolled should the project go ahead.