NOVA Build a Bridge
Classic game from PBS.com that has you pick the right bridge design for certain scenario. This is a very basic game and good for younger ages.
A collection of old Bridge Building games. I played most of them and enjoyed them, but they are aging now and may not work on newer computers.
A Bridge Design Game
Free and Open Source bridge design game. You have to make a free account at codeproject in order to download the game.
The Bridge Designer
Perhaps the most famous bridge building game, it certainly is a good one. Originally developed by engineers from the United States Military Academy for a worldwide contest, this is a free program for anyone to use and enjoy. The contest is no longer active, and the software hasn’t been updated since 2016, but it is still a great program and I highly recommend it.