In the US, most of the train technology is old and not cross compatible, making each installation difficult and expensive. Looking at the NY metro area trains a

In the US, most of the train technology is old and not cross compatible, making each installation difficult and expensive. Looking at the NY metro area trains and driveways, there are frequent mechanical issues, both on the trains themselves and on the train instructions such as switch problems, sometimes necessitating reversing back a few stations in order to switch tracks.