Steel deck bridges have been a topic of concern regarding their performance and safety over time. The study looked at old steel deck bridges in Europe and the US to see how well they held up. Some bridges are over 15 years old, while others are from the 1930s. After 27 years of service, the steel decks of these bridges were found to be in good condition, showing that with proper maintenance, steel decks can last a long time without significant deterioration.