Lifespan of a Bridge

Yesterdays news of the collapse of the I-35W bridge in Minneapolis, Minnesota (which I've traveled across many a time) should give new light that the structures we rely on everyday have a life cycle much as we do.

Bridges don't just sit there shouldering the burden of daily commuters, trucks or trains. The are a living entity. They expand in the heat, contract in the cold, vibrate and shudder from the weight of the wheels rolling across them. The weather effects them as does things like salt in the winter months as well as the liquids that ooze from the vehicles they were built to carry.

All of this causes bridges to moan and groan both in an audible and silent form. We can hear the sounds of expansion and contraction. What we don't hear is the sounds of decay from corrosion or water trickling into cracks and crevices turning into ice during freezing temperatures. The ice expands cracking the concrete around it. Eventually this cycle of life impacts a toll on the life of the bridge.

Inspectors look for these signs of decay and disrepair, but we as society take for granted these vital components of our transportation infrastructure. Budgets are shifted elsewhere to more visible and seemingly tangible things like the roads themselves.
Pot holes get more attention than the beams of a bridge that carry us across a span. Unfortunately, this factor comes into play when inspectors look at a bridge's condition. Many minor flaws are deferred as a low priority due to funding for such repairs. As with things that effect our bodies, some things are accumulative and at some point become a problem. Usually with catastrophic results.

It is time America to re-prioritize where the funds we spend on our transportation infrastructure goes. Maybe a few potholes can go unfilled to save another bridge from falling into the river it spans. Remember that the next time you cross even a small bridge, you may be the one experiencing a momentary sense of weightlessness followed by a sudden impact as you crash to the bottom.