Wiener Linien[a], the people who run the public transport system in Vienna, have in their wisdom given me not just one tram line right outside the door, but two. We'll diplomatically skip over theoretical origins for it, but the trams do run on time. (No seriously, Vienna has, bar none, the best public transport system I've ever used.)
This blessing comes with a catch, though: Sometimes, the tracks have to be polished. Or welded. Or something. It takes a good while, at any rate. The picture below was taken July 4, of the crossing of the 49 and the 5 tram lines (Westbahnstrasse / Kaiserstrasse). Two tram lines, each having a track going each direction means four intersection points.
Ten days later, as I write this, they just moved from one corner to the next. It is kind of beautiful with the sparks flying, but the equipment makes a lot of noise.
One must have some respect for these guys, though - they work at least until 3 a.m. ever night. (That's when I fall asleep, track-polishing machine going at it at full decibels or not.)