The LNP has called for a parliamentary inquiry into the state's toll road operators, saying Queensland drivers are submitting more complaints to the Tolling Customer Ombudsman than the rest of the country combined.

Opposition Leader Deb Frecklington said drivers are "being taken for a ride" and the toll roads are being underused, which is contributing to the south-east's congestion problems.

The Clem 7 tunnel entrance. Credit:Glenn Hunt

“Our toll roads are underused and our toll company tops the table for consumer complaints,” Ms Frecklington said.

“We should be busting congestion by making the best use of all our roads, tunnels and bridges.