I’m pretty sure they’re underestimating the costs of their proposed route change. It also adds quite a lot of extra travel required - in their scenario, you have to go quite a ways north that’s not strictly required. The US190 route is by far the more straight line.
It also goes through far fewer of the well known speed traps in the area and is in an area that is sparsely populated so it will qualify for the 80 or 85mph speed limit. This proposed route change would go through or near too many towns and would likely be limited at 70.
I say build it as originally planned and approved.
Anybody that went through the last oil boom in the Permian Basin knows this for what it is. Another boondoggle."bridge to nowhere".