This is a sight you don't often see in America, at least not any more. It's something I never saw before I got to Europe.
I like tram lines because they're like mechanical spiderwebs. I like them because they remind me of long exposure photos, the kind where you see not only a person but the trail of their movement hanging behind them in the air.
Trams are ways of connecting places, and tram lines are those connections hanging in the air, before and after the cars go past.