The £1.35bn bridge over the Forth - which opened to traffic in August 2017 - won the infrastructure category at this year's Rics Awards grand final.
It was built alongside the existing Forth Road Bridge and carries the M90 motorway across the Firth of Forth between Edinburgh, at South Queensferry, and Fife, at North Queensferry.
Judges hailed the crossing, the world's longest three-towered, cable-stayed bridge at 2,633m (2,880 yds), a "worthy winner".
Rics judges said the bridge had opened after "only four years' planning and six years in construction".
They added: "In addition to this impressive feat, the out-turn cost improved from the original budget of £3.2bn to a final cost of only £1.35bn.
"This new bridge is a worthy winner in this category and a tribute to collaborative teamwork..."