The ESG was kind enough to let me scan their information for posting on the site. Since then (2000), they have received Cityrunners.

Linz's streetcar system now includes a 1.9 km subway. A tram tunnel runs under the central railway station with 2 underground stations (Hauptbahnhof, Unionkreuzung) and one semi-underground one.

Underground Project Site

Photos courtesy Harold Jahn, www.tramway.at


Linz Streetcar Lines:
 
 

Line	Route	Length
Line 1	Universitat - Auswiesen	14 km
Line 2	Simonystraße - Ebelsberger Schlossweg	3.6 km
Line 3	Hauptbahnhof Linz - Bergbahnhof Urfahr	3 km
Bergbahn (Postlingerbahn)	Bergbahnof Talstation - - Postlingberg	2.9 km

If you want it graphically, I've scanned a map.
 

Read about the Postlingerbahn and the Grottenbahn.