I suspect the winning bridge design in Baltimore is going to include massive starlings, beyond what is normal, or some other mitigation factor for the last disaster.
So maybe earthquake-proofing is a fair comparison, cost-wise.
They’re just going to put more dolphins around the pylons. They had a few already but they were poorly placed and had an opening a container ship could slip through.
It definitely needs to be earthquake-resistant; we get earthquakes here constantly.
Another interesting fact about the Tokyo Gate Bridge (from the Wikipedia article): it's basically made of 3 sections, the two sides and one smaller piece in the middle to connect them. The two side pieces are cantilevers, so they're self-supporting. So if a big container ship managed to strike one side and knock it down, theoretically the other side would remain standing, rather than the whole thing collapsing like the Baltimore bridge.
So maybe earthquake-proofing is a fair comparison, cost-wise.