Local trains in Mumbai carry more than 7.24 million passengers every day. The passenger density is unparalleled in any city railway system. The entire route is electrified and there are trains running every 3-4 minutes during peak hours.
The shot was taken in Vasai. The train was headed to Churchgate which is the last station in Western Railway on South Mumbai side. At the other end is Virar. Services in Western Railway have been now extended from Virar to Dahanu.
Shutter speed was 1/500 sec. at f/3.3. Focal length was 9.3 mm at an ISO speed of 100.
You can see the photo on my photostream in Flickr.