Why are the automatic platform gates taking so long to install?

posted by  Yubi | 8 years, 8 months ago

Yesterday, a near-blind person fell on to the tracks and got killed, at a subway station in Tokyo.

Tokyo Metro, the subway operator, says that it will take another year for them to complete installing the platform gates that can easily prevent these accidents.

What makes it take so long to install them? I know that there are many stations, but are there any other reasons?