I'm not sure what the rules are in the US but in Australia the infrastructure service life is set by regulation. It's not an economic / financial argument or ev

I'm not sure what the rules are in the US but in Australia the infrastructure service life is set by regulation. It's not an economic / financial argument or even a benevolence / moral argument that causes this, it's a legal requirement. There are significant real world advantages of having a bridge last more than 25 years that are not reflected by a financial return on investment.