Pont Briwet demolition plans approved by Snowdonia National Park

Pont Briwet has a single-lane road and carries a railway line

Plans to demolish of a rare Grade II-listed wooden viaduct and replace it with a new road and rail crossing have been approved.

Pont Briwet, near Penrhyndeudraeth, Gwynedd, carries the Cambrian Coast railway and has a single-lane toll road for cars.

Snowdonia National Park approved the demolition and the new bridge, which will include cycle paths.

Pont Briwet has stood since 1867 and was partially rebuilt in 1932.

The bridge crosses the boundary of Snowdonia National Park, and carries only cars and trains.

Lorries and buses face an extra 8m (12km) journey from Penrhyndeudraeth to the Harlech road.

'Significant advantages'

The new crossing is a joint project between Network Rail, Gwynedd council, Snowdonia National Park and the Countryside Council for Wales.

A Snowdonia National Park report said the old bridge was "very rare".

"The current bridge is recognised as an iconic structure and it forms a striking and memorable access for travellers reaching the National Park from the direction of Penrhyndeudraeth," said the report.

"The Countryside Council for Wales considers it to be a crossing that is nationally important in terms of landscape and it is very rare in context of the United Kingdom."

The report described how the national park's planning and access committee had given "detailed attention" to demolishing the listed bridge.

Following a meeting last month, the committee said the redevelopment would create "significant advantages to the community that would outweigh the loss as a result of the demolition".

The report said the applicant wanted to provide a road that was "suitable for use by all vehicular traffic groups".

It added: "The proposed combined bridge is of concrete construction. It will be approximately 18m wide in comparison with the 8.5m of the existing bridge."

Construction of the new bridge is due to start this year and should be completed within two years.