>>> More than 26%, or one in four, of the nation's bridges are either
>>> structurally deficient or functionally obsolete.
>
> Schafer's reply to this (from article at the link above):
>>
>
> A "structurally deficient" bridge can safely stay in service if
> weight
> limitations are posted and observed and the bridge is monitored,
> inspected, and maintained. A bridge designed in the 1930s could be
> deemed "functionally obsolete" because it's narrower than modern
> standards dictate or because its clearance over a highway isn't up
> to
> modern snuff, not because it's in danger of tumbling down. (The
> Department of Transportation's 2004 inventory found 77,796 U.S.
> bridges
> structurally deficient and 80,632 functionally obsolete, for a
> totally
> of 158,428 deficient bridges.)
Did you look at the ASCE's bridge page? Did you see this?
<http://www.infrastructurereportcard.org/fact-sheet/bridges>
"These bridges are not unsafe, but must post limits for speed and weight. A functionally obsolete bridge has older design features and geometrics, and though not unsafe, cannot accommodate current traffic volumes, vehicle sizes, and weights. These restrictions not only contribute to traffic congestion, they also cause such major inconveniences as forcing emergency vehicles to take lengthy detours and lengthening the routes of school buses."
Also, something happened in 1992 that reduced dramatically the number of deficient bridges. They're in a rising trend since:
<http://www.fhwa.dot.gov/infrastructure/asstmgmt/vmt02.cfm#ex0206>.
> None of this is to suggest that we needn't worry about repairing or
> maintaining bridges, only to observe that the state of the nation's
> bridges ain't as dire as the press makes it out.
>
> <snip>
>
> So credulous is press coverage that reporters almost never ask
> whether
> some Rust Belt bridges might be redundant or economically
> superfluous
> because industry and population have moved on. And just because a
> bridge occupied a place on the traffic grid once shouldn't give it a
> right to eternal service.
But is this really the case? Or is Shafer just pulling this out of his ass?
As the ASCE says: "While some progress has been made in recent years to reduce the number of deficient and obsolete bridges in rural areas, the number in urban areas is rising." That suggests that, as my late friend John Liscio used to say, there's a code brown on Shafer's data.
And, like I said, bridges got the best grade in the ASCE's infrastructure report. What about the rest of it?
> For those of us who track infrastructure madness in the press, the
> current round is mighty familiar. As deplorable as our bridges may
> be,
> they're better than they were a generation ago. Today, the
> government
> classifies about 25 percent of U.S. bridges as structurally
> deficient
> or functionally obsolete. A July 18, 1982, New York Times article
> headlined "Alarm Rise Over Decay in U.S. Public Works" cites
> government
> statistics that classify 45 percent of U.S. bridges deficient or
> obsolete.
>
> <end excerpt>
>
> That last stat gives me a little pause. We improved by almost half
> in the last 25 years? When government has been starved and there's
> been zero alarms? In that case, Why shouldn't the figure 25 years
> from now be 12% just following business as usual? I'm not saying it
> will. I'm just being a devil's advocate -- why shouldn't it, if the
> secular trend has been radical improvement?
As the ASCE says: "A $17 billion annual investment is needed to substantially improve current bridge conditions. Currently, only $10.5 billion is spent annually on the construction and maintenance of bridges." That's probably why.