The inner city bypass is heavily congested inbound after an accident in the RNA Tunnel that earlier closed the major arterial and left a car on fire.

The Queensland Fire and Emergency Services arrived at the scene a little after 9am, QLD Traffic Metro reports.

One lane inbound has since reopened, but traffic remains backed up on to Sandgate and Lutwyche Roads. The Queensland Police Service has asked motorists to seek alternative routes into the city.

Update: the accident has been cleared. Remaining delays should ease quickly.