I took this at the zoo stop on the DPML (Liberec) tram system. The dual gauge is in order to facilitate operation to Jablonec, which has a 1-metre narrow-gauge tram system. Actually, as pre-1990's tram lines go, this route is relatively new, having not been completed until 1955. Since 1969, however, the line to Liberec has been the only surviving tram line in Jablonec, and is now operated by DPML. Even the line to Liberec saw sporadic use in the 1970's and 1980's, as reconstruction work was done, and planning argued over. The current operation dates to December 17th, 1989, exactly one month after the Velvet Revolution. The line is currently under reconstruction again, so I'm not aware of what the current service disruptions are. It is proposed as part of the new rebuilding to convert the Jablonec line to standard gauge, but I didn't see evidence of this for certain when I was in Jablonec or Liberec.