No ND filter. Actually was blind luck... dark inside the station with bright light leaking from the streets and the gaps in the roof. Knowing my camera's auto-metering, the station would come out way under-exposed, so I dialed in +2EV compensation and fired. We were in a hurry to catch the train, don't even remember looking through the viewfinder. At home, blew out the highlights even more, pumped up the noise removal to cancel out distracting details and emphasize the lines.