All fo these complaints about violations of our Constitutional rights are pretty meaningless in the context of public transportation, but they do illustrate a very important point. The whole notion of "public transportation" has no foundation in Constitutional law, since the Constitution could not possibly have envisioned a scenario in which government agencies would oversee the operation of this kind of public infrastructure.
The only "Constitutional" approach to this situation is to shut down the damn subway system and fill all those tunnels with concrete. This type of thing simply isn't conducive to a free society.