You may have hit on something there.

The (rail) transit business lives on Federal and State money, so they're always chasing the regulations and political process that goes with the money. It's also a very small market, so there's not much potential for competition and not enough ongoing business to keep multiple suppliers working. For practical purposes, all rail transit products are custom because even if they're a variation on a previous model because the "line" has to be restarted each time from scratch with modified designs that address the parts currently available -- so the cost of starting the factory for, probably, one order will of course be charged to that contract with a suitable profit margin. Ask the Air Force how that works ... the $500 toilet seat actually has a logical if laughable explanation.

Standardization like the PCC won't work now either since the Feds would have to be involved (not another Standard LRV, please!) to make it legal for public contracting. There are also of course the political situations, which I suspect occur with private companies too but since they're not using taxes it's less obvious, and far less of a problem because it's self-correcting as the real mistakes get trashed early.

Crazy thought: if transit could be set up as a quasi-private operation similar to, say, Amtrak with a more logically selected Board of Directors and management structure, could they bypass some of the less productive monkey-motion imposed by Fed money and general governmental requirements? Remember, government isn't supposed to be efficient; if it were, it would be scary (paraphrasing something seen in a Tom Clancy novel).