Why are public works projects like the Honolulu Rail project nearly impossible to stop once they have been approved, even if later cost estimates skyrocket?

There are several reasons why this type of projects are nearly impossible to stop once they have been approved, even when costs skyrocket.

First, it is difficult to stop these projects because, when these start, a lot of moeny is put into them. When the cost begins to skyrocket, people believe that to stop the project would mean wasting all the money already invested. This prevents people from stopping the projects.

Another reason is the fact that many different companies, investors and institutions are involved in these projects. Coordination is difficult, and pmany parties have a vested interest in the completion of such works. This makes it difficult for the different parties to agree on the right moment to stop.