When taking the MRT to work, we are probably too preoccupied with our thoughts to notice what other commuters are doing.
But photographer Edwin Koo has managed to capture these moments, providing a peek into how travelling can be for the thousands who have to deal with the peak-hour crush.
Mr Koo started taking the photos in 2011 when he returned to Singapore from Nepal after two years.
He said: "When I saw how crowded Singapore's trains had become, I started to photograph the situation out of a sense of frustration and alienation.
"I was protesting against the system. When my anger died down, I realised that there are interesting things I could observe from the frozen moments at the train doors.
"Each scene presented a glimpse into the Singapore we live in today."
This insight inspired a new collection of photographs he took from last October to this February.
These have been compiled into a photobook called Transit, which is part of a series called TwentyFifteen. It is project initiated by a group of local documentary photographers called Platform.sg.
Platform.sg is funding TwentyFifteen, which will see 20 photo books published.
The sales of Transit, which costs $25, will go towards funding the subsequent books in the series.
Mr Koo's book was launched on Tuesday, Apr 7, at the National Museum of Singapore.
He also uploaded the pictures on Facebook last Thursday.
Since the upload, 12 people have come forward asking for prints of the photos they were featured in.