One of the questions that I’ve always wondered about is why it’s necessary to have, say, 12 major projects going on in Texas with light funding, so that they take an average of 15 years to complete (i.e., 180 project-years of traffic disruption).
Why not fund the projects better, so that you get them done faster - say in 5 years (tops)...so you triple the funding for each project, but cut the number of simultaneous projects down to 4. Then the disruption over 15 years is just 60 project-years, one third of the disruption, but just as much work completed. If you get the average down to 3 years, then just 36 project-years.
I realize there’s a limit to how fast a project can move, but I suspect most major projects, if optimized for speed can easily done in 5 years, if not 3 years. Now it will make the construction zones at any one time a lot longer (like 25 miles at a time, rather than 5 miles), but it doesn’t help much to have most of the highway free of construction, but still have a choke point where the work is going on. Just go there with a bunch of equipment, tear up everything at once, rebuild everything at once, AND BE DONE - and at no extra cost.
I suspect that the time to complete projects in Texas, especially near the Gulf Coast, has to do with the type of soil, especially if there are overpasses involved. Something to do with settling time I think. I’m not a civil/structural engineer.