This is a wooden bridge carrying both the single track of the Cambrian coast railway line and an S1 toll road (suitable for light vehicles only), between Penrhyndeudraeth and Llandecwyn. The access to the bridge is manually controlled by two aspect traffic lights, from the toll booth at the bridge's northern end.
The bridge cuts the corner when travelling from the A487 Penrhyndeudraeth to the A496 for Harlech, shortening the journey by about eight miles.
At the present time (June 2009), the toll doesn't appear to be actively collected and the traffic lights are not used. Traffic flow is a free-for-all, with priority given to southbound traffic by STOP signs on the southern approach. The toll booth has been bricked up.
Construction began in March 2013 on a concrete replacement bridge. This will begin with the railway element of the new bridge, on the downstream side of the existing bridge, and a temporary road bridge on the upstream side. Then the old bridge will be demolished and the S2 road element of the new bridge will be built in its place. Then the temporary road bridge will be demolished.