Hello, you are listening to Tap Target and I am Wei Lin Tan. This show is about the design decisions behind the things you use without thinking, and today it is one you probably touched this morning: a metro ticket gate. My guest is Marcus Ho, who spent three years designing a new gate for a very busy line, and he had a brutal target. From tap to open, under half a second, every time, for a commuter running late, a tourist with the wrong card and a parent with a pram. We talk about the beep nobody hears, the fake station they built to test it with two hundred volunteers, and the one thing he would change. You are listening on Witspeak Podcasts. Tap in, let's go.