Every transit rider does it at one time or another.
He buys coffee, tea or soda before he enters the subway, gets on the train, and sips his drink during the long train ride.
Then, at the station where he leaves the train, he disposes of the container in a trashcan on the subway platform.
However, if the MTA has its way, there will be fewer and fewer places on the subway system where you can do this.
Starting on Sunday, Sept. 2, MTA New York City Transit is expanding its pilot program to remove trashcans from stations.