Yes they certainly succeeded in making it look robust! You are correct in saying that this desire was based on a previous accident where a bridge collapsed - although it a bridge in a different location (over the Firth of Tay at Dundee rather than the Firth of Forth near Edinburgh).
One interesting thing if you like Science Fiction is that Iain (M) Banks grew up in North Queensferry, which is right under the north end of the Forth Bridge - which completely dominates the wee town. I remember hearing in an interview that Iain claimed that his fascination with megastructures (e.g. Culture GSVs and Orbitals) probably came from growing up in an environment dominated by a Victorian megastructure.
He even set one of his novels on a fictionalized mega-sized version of the Forth Bridge: