Metro escalator refurbishment matches speed to the time of day
https://www.railwaygazette.com/metros/metro-escalator-refurbishment-matches-speed-to-the-time-of-day/62249.article
When it comes to adjust throughput, the number of doors per carriage about new rolling stocks is usually adjusted. But, to prevent overflow of passengers, speed of escalators should be adjusted. I didn't come up with this idea.
