Leader comment: Queensferry Crossing a test of endurance

To the many accolades heaped on the new Queensferry Crossing '“ '¨its engineering skill; its grace and elegance '“ comes another: that it could endure for 150 years.

Final works being carried out on the Queensferry Crossing, the new road bridge over the Firth of Forth. Picture: Jane Barlow/PA Wire

Mike Glover, the bridge’s technical director, says the design life of 120 years may prove a modest estimate and that it could last some 30 years longer than previously thought.

Sceptics may scoff at such a claim. But is it really so unlikely? The rail bridge across the Forth, hailed across the world as a Scottish engineering masterpiece, is 127 years old – and looks as sturdy as ever.

The Forth Road Crossing, completed in 1964, was then the longest steel suspension bridge in Europe. It was hit by deterioration and structural issues and there was talk a decade ago of imminent closure. But maintenance work should ensure it remains in operation until at least 2020, giving it a lifespan of 56 years.

The new Queensferry Crossing will help address the relentless increase in road vehicle traffic. But who knows how we will travel in 2167? Perhaps by then our driverless cars will have flight capacity and speed us across on a simple command: “Alexa – beam me over!”