America has a lot of bridges, more than 600,000. Many of them are in disrepair or are reaching the end of their planned lives.
According to the 2017 Infrastructure Report Card from the American Society of Civil Engineers, 9.1 percent of the country’s bridges were structurally deficient in 2016, meaning that drivers made an average of 188 million trips across a deficient bridge every day.
Inspecting bridges, then, is a critical activity for many states. Several states are looking at bolstering that activity by using drones, including Minnesota, which has been studying their use for years and is planning to make them a standard part of its bridge inspection toolkit.
Minnesota isn’t among the states with the highest number or percentage of deficient bridges, but it cited the increasing costs of bridge inspection as a reason for kicking off its study of drones for that use.
“We think it is really a good tool for bridge inspections,” says Barritt Lovelace of Collins Engineers, the principal investigator for the company, which headed up Minnesota’s study.
“It does a lot of things that really are advantageous if there are bridges with things that are difficult to access.”