Bridge builders mostly don't have to design for adversarial attacks.
And the ones who do focus on portability and speed of redeployment, rather than armor - it's cheaper and faster to throw down another temporary bridge than to build something bombproof.
This is exactly the problem. You can't build bridges if the threat model is thousands of attacks every second in thousands of different ways you can't even fully predict yet.
And the ones who do focus on portability and speed of redeployment, rather than armor - it's cheaper and faster to throw down another temporary bridge than to build something bombproof.
https://en.wikipedia.org/wiki/Armoured_vehicle-launched_brid...