WCAX.COM Local Vermont News, Weather and Sports-The State of Vermont's Bridges

The State of Vermont's Bridges

Middlesex, Vermont - August 2, 2007

No Vermont bridge has failed to the point of collapse in more than 80 years, but many of the older bridges in the state are showing their age.

Of the almost 4000 bridges in the state, about 16% of them are considered structurally deficient.

Dryver Huston has been studying bridges for more than 25 years. As a professor of mechanical engineering at the University of Vermont, Huston knows all about the state of Vermont's bridges.

"The failures in Vermont have been much more graceful, but there have been numerous ones where bridges have become so degraded that they've been taking out of service and that's what we like to see from a design point of view, that they fail gracefully. Of course we would rather see them maintained and not fail at all," he says.

And so would the Vermont Department of Transportation, who says it has been working hard to fix bridges.

"It's going to take some time. We didn't get to this problem overnight. This is a problem that's been developing for decades, and it's one that's going to take a few years to get us on the right track," says Neale Lunderville, Vt. Transportation Secretary.

According to Lunderville, getting on the right track means almost doubling the money spent on bridge maintenance. The state spent about $16 million on bridge repairs in the last fiscal year.

"What we do know, is that we take the safety of these bridges very seriously. That's why we're out there inspecting them regularly. The ones that we find to be in worse condition, inspecting them more often, and really, like I said, having eyes on the ground everyday through our districts in looking at those bridges. If they see something askance, they are going to let the bridge inspectors know, and the bridge inspectors are going to take action by doing a more thorough inspection there," says Lunderville.

But the question remains. Is it likely that one of Vermont's bridges will collapse like the one in Minnesota?

Reporter:  "Do you think that something like this could happen in Vermont?

"Well, it could," says Huston.  " Big bridge failures in North America occur once or twice a decade.  Aside from earthquakes, they are their own separate issue, so it's possible.  But, again, if you're just looking at the odds, probably not likely."

It's important to note that just because a bridge has been deemed structurally deficient, that does not mean that it is unsafe.

When inspectors look at bridges, they rate three main categories from 1 to 10:

1. The Deck -- which is the main road structure
2. The Superstructure -- the span of the bridge that holds up the road
3. The Substructure -- holds the bridge to the ground on either side

If the average score of those criteria comes at a 4 or under, the bridge is considered structurally deficient.

If a bridge is found to be structurally deficient, one of four things can happen. The state can do nothing, meaning the bridge is still considered safe to drive over. It can also close the bridge, post a weight limit, or in the case of the Bridge Street bridge in Richmond, close one lane of traffic to reduce weight on the bridge.

Alex Martin - WCAX News