The hideous rumbling and grinding sound of last Wednesday's bridge collapse in Minneapolis was, at least in part, the sound of natural consequences for being penny wise and pound foolish.

The I-35W bridge, only 40 years old, collapsed, and plunged dozens of rush-hour commuters 60 feet to the Mississippi River. Considering all of the motorists crowding the span when it collapsed, like huge concrete cards, we're somewhat amazed that the tragedy wasn't worse.

It's something that the nation's civil engineers say, too. Our nation has 590,750 bridges. The I-35W was among the 159,000 that the American Society of Civil Engineers dubbed "deficient" or "structurally deficient" in a 2005 infrastructure report.

It's frightening that the Federal Highway Administration's bridge inventory used the same words - "structurally deficient" - to describe about 73,000 bridges. The phrase "functionally obsolete," was applied to the 80,000 additional bridges that are carrying more traffic than they were designed for.

"Structurally deficient." "Functionally obsolete." What polite, meaningless jargon when all we want to know is whether we're rolling the dice if we decide to roll onto such bridges.

We're all for asking the feds and the state to start posting clearly stated bridge ratings. But, apparently, we aren't in real danger as long as we stay within Oregon. Washington was quick to announce Friday that its bridges were in pretty good shape, too.

We're fortunate in Oregon that we saw the potential for bridge collapses four years ago, and have since instituted an aggressive bridge replacement and repair policy.

What's more, the Van Buren and Harrison bridges have recently been inspected, and both are in better structural shape than many others in our vicinity.

But is that really comforting? We're a mobile nation, and we care about more than just the bridges of Benton County.

It's cold comfort, for instance, that the picturesque antique in Portland, the 1912-era Sellwood Bridge, is not meant to take all the traffic that it does. It was designed when draft horses and buggies hauling ice would have been considered a big load.

We are grateful that our state's bridge repair project has been in the works for four years, but we're also glad that, two years ago, Rep. Peter DeFazio brought home $2 billion in federal highway and transit projects to see Oregon through until 2010.

We're grateful for it now, as a huge chunk of it was earmarked for bridge upgrades.

Although we're pretty sure that the Oregon Department of Transportation already knows where the "deficient" bridges are, we're glad that Gov. Ted Kulongoski on Friday ordered a closer look at all the state's bridges, just in case.

But that leaves us, at the height of vacation season, and with loved ones scattered all over the country, wondering: What can be done to warn us which bridges out there are among the "structurally deficient" or "functionally obsolete" 159,000?