The thing is, we've been underestimating bridge failure potential for decades. At least with reinforced concrete bridges, corrosion is deadly and silent, and some substances took decades to slowly corrode the steel. It took unexpected catastrophic failure for us to understand how to build them better.
The real killer here is salt on the concrete in winter. It slowly leaches through the top level of the concrete and starts eating away at the steel. Very effective, totally invisible. Also lots of balconies at risk because of this.
Balconies and galleries in apartment buildings to avoid falls in winter.
There's a huge flap around that theme here in NL right now with 1000's of apartment buildings having to be inspected before mid-june because a building shed it's balconies.
