The Invisible Man

I was driving today to work - and I was a bit late, therefore in a slight hurry (festina lente)... not much traffic, thank God. However, this traffic light, right, at a zebra crossing, right, suddenly turns red. All the cars grudgingly stopped, neatly, waiting for the pedestrian(s) to cross. What pedestrian(s)?! Nobody there! Well, it should have been someone, as the light won't turn red unless some damn cheeky pedestrian presses the button (when they have the audacity to want to cross the road).
But there was nobody there!
And I was thinking, you know (yes, it did hurt a bit in the process) - perhaps it was the Invisible Man who pressed the button. But why, me keeps wondering, why the f*** did the Invisible Man cross the road?!?!