During an inspection along Interstate-95 in Prince William
County, technician Bernie Sevilla places an ultrasonic
transducer atop an anchor bolt. The sound waves show no crack or
irregularities in the roads, which are scheduled to inspection
every five years. "I am setting it now to a 100-inch range, and
you can see that we have a spike at 51 inches down," he says.
"It's reading the length of the bolt, the anchor bolt." Sevilla
and a few other technicians with the Virginia Department of
Transportation are using new technology to monitor the state's
infrastructure stress. Over time, roads, bridges, and even
highway signs eventually begin to wear down under the weight of
countless cars and rigs, so staying ahead of maintenance is
important. "I don't know if you could do this type of inspection
without this equipment," says VDOT technician Craig Freidline.
"We are testing the bolt below concrete level." To detect
problems hidden from the naked eye, the inspection teams employ
high-tech devices on hundreds of sig