I'm not aware of any metro system in the world that has scheduled headways of under a minute. The Moscow Metro was tops for a long time with 95-second headways on some lines at peak (without full automation, mind you), but Paris Metro Line 1 was recently fully automated and can go as low as 85 seconds. Singapore currently has 120 second headways on its busiest line (East/West, which is not automated) and is working on getting that down to 100: https://medium.com/from-the-red-line/36-just-a-number-21011a...

Note that headway is measured between the arrival of trains, meaning the train has to come to a complete stop, let people get on & off, close doors, speed off and have another train stopped all within that period! So a 90-sec headway will feel like less than a minute to users.

Victoria line on the London underground does 100 seconds, with plans for the Northern Line to reach that too FWIW.

Doesn't really help much though. Sometimes you still have to wait 2 or 3 (or more!) trains before you can get to the front of the platform edge so that you can actually get on though!

TPH on Victoria line is now limited by platform constraints I think, you literally can't move passengers through stations like Stockwell any faster because of the size of the passageways.