MR. SABRI BEN-ACHOUR
So here's a question, how often do you imagine ramming other cars when you're stuck in traffic? Is that just me? Well, never mind. My point is commuting is stressful, okay, which we all know. But it's just as bad for the roads and the bridges that carry us And that's the topic of our weekly transportation segment "From A to B."
MR. SABRI BEN-ACHOUR
Transportation reporter, Martin Di Caro, hit the road in northern Virginia this week to find out how transportation agencies are using high-tech equipment to measure stress on and in our local infrastructure.
MR. MARTIN DI CARO
As you whiz down the highway, you're focused on getting where you need to be, hoping you don't get stuck in bumper-to-bumper, maybe hating the Sunday driver in front of you in the left lane. You're not thinking about whether this highway sign might fall over. Men in hard hats kneel down around its space using a good old fashioned hammer to perform a preliminary inspection.
MR. CRAIG FREEDLINE
It's just a test to see if these nuts are loose.
Don't worry, the sign is sturdy. The reason why technicians at the Virginia Department of Transportation know that is that they're also using technology more advanced than a hammer or power drill.
MR. BERNIE SAVIA
It's an ultrasonic testing equipment using sound waves. What I'm holding now is actually emitting a sound wave through the rod.
This is cantilever sign structure.
Meaning that you have a vertical pole and then you have a horizontal arm that's suspended, that's attached to the pole and then suspended out over a traffic lane.
Near exit 160 here on 95 North in Prince William County is held down by four vertical rods. Technicians, Bernie Savia and Craig Freedline, are using ultrasound to see more than four feet down into the concrete if there are any stress-related problems in the rods.
I'm setting it now to a 100-inch rang and you can see that we have a spike at 51 inch.
51 inches down.
It's down. It's reading the length of the anchor bolt. That's the entire length of this bolt.
I don't know if you could possibly do this kind of inspection without that equipment. We're testing the bolt below concrete level.
These tests make clear, stress affects concrete and metal as much as our blood pressure and nerves.
Everything you can see on the road is being stressed out, whether it be another human being, their vehicle, the signs. Everything is stressed.
Nicholas Roper, VDOT structure and bridge engineer for northern Virginia explains how.
MR. NICHOLAS ROPER
An overload on the anchor bolts could be caused by very high winds, an exceptional ice storm that puts additional vertical loads on the sign that the anchor bolts eventually have to carry. If one bolt was cracked and became overstressed, that would put additional stress on the other three bolts.
To detect problems hidden from the naked eye, Roper's teams of technicians are employing the high-tech on hundreds of signs like this one and also on the hundreds of bridges across the interstate. They use ultrasonic devices, ground penetrating radar and infrared thermo graphics.
The way that works is you're looking for what we call dalamination, which is a separation of concrete into different layers.
Finding cracks and other problems deep inside structures lets VDOT stay ahead on maintenance that is so critical to commerce and commuting.
Inspections are the catalyst for just all the repair, rehabilitation preventive maintenance work that we do. The first thing you have to get is a good handle on the condition of the existing structure that you're examining. Everything else comes from that inspection.
Roper says Virginia has among the best bridges in the country, just under 8 percent fall into the category of structurally deficient. That rating means there are elements of a bridge that need to be monitored and/or repaired, not necessarily that it's unsafe.
Ideally, you're doing preventive maintenance before you even get to that so that you don't have to do repairs, but just that the number of assets that we have means that we can't deal with all of them in the appropriate amount of time.
No matter how much maintenance any state DOT performs, there's no way to turn back the clock on aging infrastructure. At the D.C. based think tank, Bipartisan Policy Center visiting scholar Emil Frankel, a former assistant transportation secretary under George W. Bush, says bridges on the interstate system are generally 40 to 50 years old.
MR. EMIL FRANKEL
The lifetime of bridges is estimated to be 40 or 50 years. Structural deficiencies even more serious risks than that are not unexpected. They're coming -- many of them are coming to the end of their lives, but the difficulty is what we do about it. We can discover the problems, but remedying the problems is quite another issue.
Until those investments are made, he says both our infrastructure and the commuters who use it every day will continue to shoulder more and more stress. I'm Martin Di Caro.
To see photos of the ultrasound equipment Martin talks about in his story, check our website, metroconnection.org. In a minute, how to support a family on a teeny tiny salary.
UNIDENTIFIED MALE ONE
I have a daughter. I have a family. I have other stuff, bills and all that stuff. I got to do it some way. I don't know how I do it, but I do it.
It's coming up on "Metro Connection," here on WAMU 88.5.
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