Much of the cost increases you see in figures like those quoted for CAHSR are related to timelines.
First, projected infrastructure project costs in the United States are usually quoted (by agencies) in year of expenditure dollars, which means projected expenditures for each particular year are literally inflated. If you push a project back 15 years, you can easily see double-digit percentage increases in quoted total expenditures. I don't know the exact figure but AFAIU this is very much the case with CAHSR--a large fraction, and perhaps even a majority, of nominal cost increases is related to inflation adjustments as the timeline keeps getting pushed back and stretched. (Of course, that still leaves a large component that isn't.)
Secondly, pushing back timelines incurs all sorts of additional real costs. For example, you have to extend supply and labor contracts, which often means you end up getting less for your money because more people and equipment will end up sitting around idle for longer. You can also incur greater financing costs.
Also, I don't think any of the figures in that therichest.com link are inflation adjusted. AFAICT, they seem to just be tallying the year-of-expenditure or perhaps year-of-completion costs. This difference compounds inflation discrepancies even more. (There are other problems w/ those comparisons, too, such as that most of those airports were built far away from developed areas, but it's not worth going down that rabbit hole.)
Time is the themostcritical component in all large construction projects, public or private. Time is money isn't just a catchphrase. If there are any hand-wavy, magical solutions to the cost problem that can be easily applied, one of the simplest and most obvious is to finish projects as quickly as possible. Don't let them linger and get stretched out.
Unfortunately, there are often political and regulatory pressures that push things in the wrong direction. If political blowback causes timelines to be stretched out, directly or indirectly, cost increases become a self-fulfilling prophecy. After learning about the accounting methods for how projected costs are quoted, and in particular digging into CAHSR costs, I vowed as a voting citizen to never oppose a project once it got off the ground, even if I initially opposed it.
First, projected infrastructure project costs in the United States are usually quoted (by agencies) in year of expenditure dollars, which means projected expenditures for each particular year are literally inflated. If you push a project back 15 years, you can easily see double-digit percentage increases in quoted total expenditures. I don't know the exact figure but AFAIU this is very much the case with CAHSR--a large fraction, and perhaps even a majority, of nominal cost increases is related to inflation adjustments as the timeline keeps getting pushed back and stretched. (Of course, that still leaves a large component that isn't.)
Secondly, pushing back timelines incurs all sorts of additional real costs. For example, you have to extend supply and labor contracts, which often means you end up getting less for your money because more people and equipment will end up sitting around idle for longer. You can also incur greater financing costs.
Also, I don't think any of the figures in that therichest.com link are inflation adjusted. AFAICT, they seem to just be tallying the year-of-expenditure or perhaps year-of-completion costs. This difference compounds inflation discrepancies even more. (There are other problems w/ those comparisons, too, such as that most of those airports were built far away from developed areas, but it's not worth going down that rabbit hole.)
Time is the the most critical component in all large construction projects, public or private. Time is money isn't just a catchphrase. If there are any hand-wavy, magical solutions to the cost problem that can be easily applied, one of the simplest and most obvious is to finish projects as quickly as possible. Don't let them linger and get stretched out.
Unfortunately, there are often political and regulatory pressures that push things in the wrong direction. If political blowback causes timelines to be stretched out, directly or indirectly, cost increases become a self-fulfilling prophecy. After learning about the accounting methods for how projected costs are quoted, and in particular digging into CAHSR costs, I vowed as a voting citizen to never oppose a project once it got off the ground, even if I initially opposed it.