Its entire length is a dual carriageway primary route, with the exception of the point where it crosses the Britannia Bridge over the Menai Strait.

The design was first used in a shorter span at Conway, and followed by the much larger Britannia Bridge.

The plan calls for construction of a bridge (Britannia Bridge) crossing the Ottawa River.

By 1840, a Treasury committee decided broadly in favour of Stephenson's proposals, with final consent to the route including Britannia Bridge given in 1845.

The most popular use of the name is for the stretch between the Britannia Bridge and the Menai Bridge.

Where the girder carries its "content" inside the box, such as the Britannia Bridge, it is termed a tubular girder.

March 5 - Opening of the Britannia Bridge over the Menai Strait.

Locally it has been called the Ethelfleda Bridge but more widely as the Britannia Bridge.

His expertise with beams led to his retention, along with Fairbairn, as consultant on the novel tubular design for the Britannia Bridge.

Cross Porthmadog High St and the River Glaslyn across the Britannia Bridge with street running.