They didn’t pay $150M just to find a good route. GoTriangle released a whole investigation on this earlier this year:
It also included detailed engineering drawings, field surveys that included underground work, a 700-page Environmental Impact Statement (which is ridiculous but also a standard amount of work for all public infrastructure projects in America, including interstate highways), value engineering (finding ways to build things more cheaply), purchasing of land for what would’ve been a maintenance yard, construction/resource scheduling in preparation for the day shovels hit the ground, and so much more.
The ugly truth is that a LOT of things need to be figured out to build a transit project. And Americans don’t pay people enough to do that sort of work in-house locally, and they also don’t invest in a central government agency where people could make a respectable career out of doing that heavy lifting on behalf of local governments across the country. Because of that gap in needs, private industry fills the gap while milking out profits, and this happens.
We talked about this before in the light rail thread, if you want to know more or you’d like to talk about that some more.