For example, the nation's bridges. Most of us don't think much about bridges until one we need is closed or is damaged or collapses, as the I-35W one did in Minneapolis in 2007, killing 13 people.
Yet engineers all over the country who really know about such things say we ought to be thinking about bridges a lot more.
And here is something we should consider: One in four of our bridges is either in need of repair or obsolete in terms of handling modern traffic and loads.
That startling fact comes from the American Society of Civil Engineers, which every few years consults with dozens of the nation's experts on all sorts of infrastructure matters. The society gives U.S. bridges a grade of C.
And bridges aren't the only problem in what we could call the State of the Union's Infrastructure. Roads, airports, water supplies, railways, dams, schools and on and on it goes; all are, according to the engineers' latest report in 2009, in pretty dire shape.
Compared with trucks, railways are much more efficient for moving goods: using about 20% less energy per mile if used properly. But comparatively little has been invested in expanding U.S. railroad capacity. Rail gets a C minus.