Contingency funds have been deployed to cover any cost blowout in Brisbane City Council's $650 million Kingsford Smith Drive upgrade.

These funds will likely be spent as Lendlease, the company contracted to deliver the project, reported a $47 million blowout.

Under questioning from Labor about the project, Lord Mayor Graham Quirk acknowledged the project had seen delays and additional costs.

Councillor Quirk said all major projects have a contingency fund set aside to cover any unexpected financial shortfall.