Scheduled to open to traffic in December this year, the bridge now has around 1,300 workers employed on its delivery.

Bosses said the cable-stayed bridge would take its full shape by the end of summer, before work begins on surfacing the road.

A total of 34 of the crossing’s 110 concrete decks – each weighing up to 800 tonnes – are already in place, with its three towers also complete. Major road links on both sides of the crossing will be completed over the next 11 months.

Michael Martin, project director for the construction joint venture, told the BBC: “I believe we can get traffic over the bridge by the end of the year. It’s not a guarantee as it will depend on the weather but I believe it is possible.

“I believe I’ve got a team of people here who are capable of doing that and who are committed to achieving that if it is possible.

“We programme optimistically and then we face the conditions that arrive.

“When we simply can’t do anything we have to accept it’s not possible but we don’t accept that willingly.”

David Climie, the project director for Transport Scotland, added: “We are on target for the end of 2016 to have traffic on the new crossing providing we get average weather.”

Plans are already under way for a series of events which will give the public a “once in a lifetime opportunity” to cross its 1.7-mile span on foot before it opens to traffic.

Mr Climie said full details on opening plans would be released by early autumn.