What tram signs taught me about interfaces

A sign has a few seconds and no undo. Someone is walking past it with a bag, a child, or a phone in their hand, and it has to work the first time.

Lead with the decision

Platform signs on Linea lead with direction because that is the decision you make on a platform. The line number comes second; you already chose it at the entrance.

Say it the same way everywhere

A station had one name on the map, a shorter one on the platform and a third in the app. We picked one and set it identically on all three. Interfaces drift the same way: a setting called one thing in the menu and another in the page it opens.

Test it in the place

We printed signs at full size and taped them up in a depot. Things that looked fine on a monitor failed at ten metres. The interface version is to test on the phone, outside, in the sun.