PLoS ONE 14, e0223307 (2019)

Bridges in the United States and around the world are both ageing and deteriorating through a combination of increased demand and inadequate maintenance. Little is known about how individual components and overall bridge performance are likely to be affected by future thermal stress from climate change.

Credit: YAY Media AS / Alamy Stock Photo

Susan Palu and Hussam Mahmoud of Colorado State University, USA, evaluate the vulnerability of 89,089 supported steel girder bridges, by far the most common bridge design in the United States, under the combined effect of accumulated debris and dirt in the expansion joints and elevated temperatures due to climate change. Each bridge was evaluated in terms of the structural performance of the main girders under RCP 2.6, 6.0 and 8.5 scenarios and with alternative debris types. They find that bridges located in the Northern Rockies and Plains, the Northwest and the Upper Midwest are most at risk, regardless of the scenario. For a 1 °C increase in temperature, the integrity of the bridges is reduced by 2%. Other aspects of bridges will be impacted by climate change, and further work is needed to prioritize repair and maintenance.