As you might expect, the photo is a mix of planning and luck
While the scene in itself is pretty much as I planned it, the taxi in the photo is quite random. The Rosenthaler Platz in the centre of Berlin is a very busy traffic hub connecting 5 or 6 streets and some tram rails.
First my plan was to enlighten the crossing with light trails, when suddenly the taxi had to stop for a full exposure (6 seconds). So I decided to build the photo around the taxi and then added trails from other exposures.