Yes — this kind of image can be made in-camera with a single long exposure. Based on the discussion and the photographer’s own comments, the shot was made on a tripod with a long shutter speed, around 2 seconds at about f/8 and ISO 100, and no ND filter. A station roof or otherwise dimmer light can make that exposure possible without extra filtration.

The effect comes from moving people blurring during the exposure while subjects who stay still remain much sharper. They do not need to be perfectly frozen — just relatively motionless compared with the people walking through the scene. In a busy station, that contrast can happen naturally.

Some viewers noted that parts of the blur look a bit “stuttered,” which can sometimes suggest layered shorter exposures, but in this case the photographer reportedly said the only post-processing was contrast adjustment. So compositing was not necessary for this image.

To try it yourself: use a tripod, low ISO, a mid aperture, and experiment with shutter speeds from about 1/8 second up to a few seconds depending on how much blur you want and how bright the scene is.