Stadtbahn Stuttgart uses “normal track width” of 1435 Millimeter. They transitioned from a much smaller track width several decades ago and used special tracks in the meantime (mixed tracks which supported both track widths). I think this picture may show some leftover mixed track (note that it’s showing a steep climb where exchanging the tracks may not be easy).
Got this info from a quick glance at German Wikipedia. Maybe delve deeper if you’re interested:
EDIT:
Forget most of my post - this is a special track for steep climbs using a special friction track in the middle that is being grabbed by a special wheel under the wagon. Line 10 is the only line in Stadtbahn Stuttgart that uses this feature. Track width indeed is a metre (1000 millimetres).
Stadtbahn Stuttgart uses “normal track width” of 1435 Millimeter. They transitioned from a much smaller track width several decades ago and used special tracks in the meantime (mixed tracks which supported both track widths). I think this picture may show some leftover mixed track (note that it’s showing a steep climb where exchanging the tracks may not be easy).
Got this info from a quick glance at German Wikipedia. Maybe delve deeper if you’re interested:
https://de.wikipedia.org/wiki/Stadtbahn_Stuttgart
EDIT: Forget most of my post - this is a special track for steep climbs using a special friction track in the middle that is being grabbed by a special wheel under the wagon. Line 10 is the only line in Stadtbahn Stuttgart that uses this feature. Track width indeed is a metre (1000 millimetres).
https://de.wikipedia.org/wiki/Zahnradbahn_Stuttgart
Ahh, interesting. I was wondering what the thing in the middle was. Thanks!