Unfortunately in the 60s and 70s steel concrete was the miracle building solution which was used for bridges was promised to stand the test of time for at least 100 years. Unfortunately road traffic grew much faster and steel concrete wasn't up to corrosion and other issues. So now 50 years later road infrastructure is crumbling. Your recent trip to Boston shows the US has a lot of these issues as well. As do most Western countries.
Unfortunately in the 60s and 70s steel concrete was the miracle building solution which was used for bridges was promised to stand the test of time for at least 100 years. Unfortunately road traffic grew much faster and steel concrete wasn't up to corrosion and other issues. So now 50 years later road infrastructure is crumbling. Your recent trip to Boston shows the US has a lot of these issues as well. As do most Western countries.