The 236-mile Kansas Turnpike was constructed in 22 months from 1954 to 1956. That is more than ten miles per month. Presumably, we have better tools today. Why in the world does it take (literally) two years replace a single bridge (I-70 near Lawrence) or 18 months to rework ten miles of roadway? Does this strike anyone else as odd?
The Los Angeles Times has a column that makes a similar point:
It took 410 days to build the Empire State Building; four years to erect the Golden Gate Bridge. The Pentagon took two years; the Alaska Highway just nine months. These days it takes longer to build an overpass.
While I have some guesses, I have no idea why construction, once started, takes so long these days. It isn't environmental regulation (once construction has started) as the Times suggests and, as I said, presumably we have better tools.
Does anyone have the answer? If you have expertise in this area, please write your thoughts in the comments area. Thanks!