WALTHAM, Mass. -- To verify the health of the nation's 600,000 bridges, state governments must conduct onsite inspections at least once every two years. For bridges deemed deficient, those visual inspections, which are costly, can occur every three to six months. But a start-up technology firm hopes to do the job wirelessly.

Senera, based in Waltham, Mass., proposes to mount sensors at different points on a bridge that measure stress and strain, gauge corrosion, watch temperature and sense vibration, according to an article in The Boston Globe. The sensors would form a "bridge area network" and would collect data from the different points and send it to Senera's data center via a cellular network, satellite or land line. Software would interpret the data and present it to a state highway department over a secure Website.

Shawn Burke, Senera's Chief Technology Officer, told the Globe that "a customer wants information that will let them better understand how a bridge is performing and make quantitative decisions about repair or replacement."

What makes Senera's solution appealing is that it would provide a highway department with objective data that would rank the bridge's condition. This information could be used to weigh decisions in the face of political pressure to make costly bridge repairs without full knowledge of the bridge's condition, according to one former transportation official.

But Senera acknowledges that it must first convince state agencies the system can save them money. According to The Globe, "that means supplying data that can show states that certain bridges they thought needed to be replaced may only require repair, or allowing states to rely on Senera's continual data feed instead of conducting frequent inspections of problem bridges."

While Senera is in discussions with three states in the northeast, including Massachusetts, state highway officials remain somewhat skeptical. "We're receptive to the idea," Jon Carlisle, spokesman for Mass Highway, told The Globe. "But until it's tested further, we wouldn't be willing to forgo the frequency of regular inspections by a human being."