A car has burst into flames after an accident on the Riverside Expressway in Brisbane's city centre.

A police spokesman said a vehicle had caught fire as a result of a traffic crash directly underneath Kurilpa Bridge on Friday.

The car goes up in flames on the Riverside Expressway on Friday afternoon. Credit:Snapchat

Police said the incident was near the Adelaide Street exit and delays were likely.

By 2.30pm, the Department of Transport and Main Roads had advised both northbound lanes had been reopened, along with the Ann Street on-ramp, with delays stretching back to Greenslopes.