> Civil engineers don’t tell your mayor or your highway commission what to build, their only job is to figure out how it can be built.

I would disagree. The engineers absolutely steer the space of available solutions. Caltrans is a prime example, I have personally met Caltrans engineers who might as well have stepped out of a time machine from 1970. This absolutely influences the priorities of both the state and the cities that depends on the framework it sets up.

And yes city politics is separately a major problem.