Pretty decent, actually. I'm in my apartment (Norway) looking out the window at the bus stop, the difference between actual buss arrival and the one on map was only 30 seconds. During rush traffic.

Here's a cool one for the London Underground - https://traintimes.org.uk/map/tube/

That's pretty cool too - no 3D wow factor, but as amazing as that looks (and it does) it is superflous; a 2D map is easier to read and of course much more performant.

Of course, this 2D map in particular appears to be built from raster images, so things look pixelated when you zoom in by pinching.

Surprised at first that there would be so many buses visible in Italy on the map, but then I also noticed "Vehicle position based on interpolated schedule data" so it means it's guessing the position based on the schedule. That could be waaaay off what's showing on the map, to the point where it's almost useless.

I was at first totally amazed that it knew where trains around me here in Sweden were. Turns out the datasource is "interpolation from schedule". Not as impressive :(