Incorrect analogy. Bridge construction is a clearly algorithmic process. All bridges resemble each other, and from an engineering perspective, designing one is not rocket science. Construction itself is a set of well-studied steps that can be easily calculated. If I were to write my operating system 100 times, I could give an estimate accurate to within 10%, but every task I’ve ever done in life is unique, and I have nothing to compare it to except intuitive judgments. Returning to bridges: there is 1% of projects that are unique, and their design can take decades, while construction might not even begin