Your cell phone in your pocket can reveal the health status of bridges as you do your daily commute
The accelerometer and GPS sensors that are standard components in smartphones collect information that can show.
That's how bridges flex and vibrate, as the researchers report on Nov. 3 in Communications Engineering.
Measurement-collecting apps can keep passengers safe by alerting engineers that a bridge is in need of repair.
"This really applies to any type of bridge," says civil engineer Thomas Matarazzo of the US Military Academy at West Point in New York.
All you need, he says, is a way to get a smartphone — whether by car, in a pedestrian pocket or mounted on a scooter — and some way to monitor the device.
Bridge failures often come about because of uncertainties about structural properties, says Matarazzo.
Crowdsourcing data from cell phones may be the best and possibly only way to get lots of data across bridges around the world.
More than 600,000 bridges exist in the United States alone. Dedicated sensors that check for structural problems are expensive.
That's why most bridges are inspected by eye, usually every other year, says Matarazzo.