Risk analysis, traffic analysis, and unusual factors

Canadian terrorists strike again: apparently we are responsible for taking down a major piece of transportation infrastructure, vis, the I-5 bridge over the Skagit river at Mount Vernon.

A friend in Seattle assures me that, while he is disappointed in us, he holds no grudges, and is willing to warn us if he hears of any drone strikes planned for north of the border.

(Allow me, for a moment, to examine this “oversized load” on which everyone is blaming the collapse.  Image 2 in the slide deck [if they don't change it] is this “oversized load.”  You will notice that it is basically an empty box with the two sides missing, and has, relatively, zero structural rigidity.  If a ding from that kind of load brought the bridge down [and didn't even collapse the load itself], the bridge was definitely unsafe.)

I drive that route regularly, and, when I heard that a bridge had gone down, that bridge was the first one I thought of.  I have always felt unsafe crossing it.  There is a wrongness about it you can just feel.

It’s also ugly.  And I am reminded of an essay by an engineer who said that bridges were the most beautiful products of all forms of engineering.  A properly designed bridge has curves, and those curves just feel right.  They are beautiful.

So, if you ever have questions about a bridge, and you don’t have enough facts to go on, just look at it.

If it’s ugly, don’t cross it.