Not sure about the WTC but I know for rail, bridge, etc. there can be lots of environmental regulations to deal with in the US. Finding a butterfly in a field c

Not sure about the WTC but I know for rail, bridge, etc. there can be lots of environmental regulations to deal with in the US. Finding a butterfly in a field can be enough to stop the work while they do environmental assessments to see how it may impact that butterfly species. I know a little bit about this because my first job out of engineering college was working at a consultant company doing the drudge work for such an assessment. After 6 months of work, I felt we barely put out anything of value while burning consultant hours. The reports were cookie cutter format from previous contracts with a few facts filled in. A friend who works for the state transportation engineering agency mentioned finding a native american arrow while expanding a highway triggering another investigation. Then there is eminent domain, noise assessments, impact reviews, etc. So basically it is not the engineering costs but all the other demands of society that make these a slow and expensive venture.