Transportation infrastructure is an essential component of our economy, and must be developed in the most cost-efficient way and with the future of related technologies in mind. Unfortunately, the way this has been done in the past has often fallen short of this ideal. Financing and managing major infrastructure through the federal government has led to misallocation of resources, because the political process simply is not a good way to manage economic activity.
Even the past projects that are widely seen as having been "successful", in that they created something we use today, may not have been the best use of the resources involved – we see what was created, but we don't see what was not created because resources were diverted from them.
Financing projects through federal taxes also creates perverse incentives for state and local governments, who must fight each other for this "free" money. Of course that money isn't free at all – the federal government doesn't create wealth, it just takes it from us and redistributes it. But state and local governments are put in a position where they must play this game, for fear of not getting "their share" of the money that was originally taken from their own citizens.
We can see the disastrous results right here in California with the failed "high speed rail to nowhere" project that has squandered billions of dollars in tax money, lining the pockets of politically-connected consultants and contractors, with no prospect of ever producing a service that will be of practical use to the average traveler or commuter. All that money could have been, and should have been, spent on something more useful.
Meanwhile, advancing technology has opened up new ways to address real transportation needs. We are on the verge of a revolution in transportation, with electric vehicles soon to become predominant, self-driving cars close to a reality, and air taxis on their way. This is not the time to be wasting tax money on massive new projects that may well become outmoded before they are even completed.
This is, rather, a golden opportunity to move the financing of transportation back to the private sector. To cut gas taxes and let investors build roadways and bridges that will pay for themselves, to let Elon Musk build his hyperloops, to enable those who believe in rail to make investments without fear of tax-subsidized competition, and to let these and possibilities not yet even imagined compete to provide the best solutions for our transportation needs.