This seems to be some kind of induction loop for communication between a
stationary tramcar and the signalbox. Like this one at the new station Weiden
Schulstraße in Cologne, I saw these things only at places where a tram
starts it's trip after changing the direction. Picture taken on 15 June 2002.
<p>
Digital photo by
<a href="http://www-users.rwth-aachen.de/christoph.schmitz2/index.html">Christoph
Schmitz</a>