Good point. Most so called "feasibility studies" in the US are really delivery systems of needed conclusions for those in the position to pay for them. I am on the board of a community association and I participate in such studies from time to time. It is quite obvious from day one that conclusions are already scripted by the sponsor and the main point of such studies is to make these conclusions palatable to the public and create an illusion of "public participation."
Most of those project try to "study" demand before the service is in place or even though of as an option by potential users. Interestingly, private marketing operates in the exact opposite way - first comes the supply and then the demand for it is created by marketing blitz. So if the government were to operate in a business like manner - as the neoliberal spin-doctors talk ad nauseam - they would first built state of the art transit network, then launched a marketing blitz to sell it the public. In reality, the opposite happens. They create the necessary minimum, crappy service only when they absolutely have to and make everything possible to reduce the demand for that service.
Another point - the unspoken yet tacitly understood element of most of these "feasibility studies" is the apartheid factor. One of the key functions of transportation (and land use) systems in the US is to perpetuate apartheid without Jim Crow laws on the book - we are "number 1 democracy" after all and such laws would make us look bad. These systems are literally designed for particular racial groups - buses for blacks, cars for whites - and make them travel separate. Subway and rail are not as good in maintaining this apartheid and that is why they are so vehemently opposed by politicians and suburban whites - they code word here is to prevent spread of "crime."
So when a "study" of a capital intensive mode of transportation (e.g. rail) says that there is not enough public demand to warrant the expense, what it really means is "not enough white suburbanites are gonging to use it, because they do not want to sit with blacks, and the blacks who will ride it are not worth the expense, they can take the bus."
Wojtek