NCB, he’s being more machmir than I. Since all poskim AFAIK asser taking trains and buses, according to RoB, elevators and escalators would likewise be universally accepted as assur under all circumstances.
I, on the other hand, while bringing opinions such as the Chelkas Yaakov and Rav Vosner, acknowledge that some poskim are more lenient with Shabbos elevators and allow it (AFAIK, only b’makom tzorech, with different poskim holding of varying degrees of tzorech necessary to permit).