The US Federal Highway Administration (FHWA) has released the latest National Bridge Inventory (NBI) data, which suggests that there has been a decline of structurally deficient bridges to 55,309 (9% of nationwide inventory) in 2016 from 118,757 (21% of the inventory) back in 1992.

The new report also indicates that since last year alone, the number of deficient bridges has been dropped by 2,735, and the number of functionally obsolete bridges nationwide has dropped slightly from 80,461 in 1992 to 75,703 bridges last year.

Infrastructure Data Solutions president Mahmoud Halfawy said: "Despite overall condition improvements over the past 25 years, big challenges lie ahead.

"A big wave of structurally deficient bridges is expected to spike over the next 20 to 30 years."

"Based on our analysis, the average age of bridges nationwide is 36 years, and given that the average design life of most existing bridges is 50 years, a big wave of structurally deficient bridges is expected to spike over the next 20 to 30 years.

"To sustain past progress, agencies will need to get aggressive in implementing new efficiencies and introduce innovation in bridge preservation, programming, and project delivery."

IDS, a US-based technology company that developed software’s such as Bridge Optimizer and Roads Optimizer to help transportation agencies design and develop optimal long-range performance-based improvement programs.

The report also suggests that nearly one in five bridges in the US is in need of some improvement.

Many of these bridges will soon be due for major rehabilitation or replacement, and with existing funding levels available to the agencies, it is extremely challenging to keep up with the expected needs.