▁to ▁be ▁completed ▁at ▁the ▁end ▁of ▁ 2 0 2 1 . ▁ ▁L ines ▁, ▁the ▁tram ▁network ▁in ▁Kar ls ru he ▁oper ates ▁on ▁ ▁of ▁route ; ▁the ▁total ▁line ▁length ▁of ▁the ▁system ▁is ▁. ▁The ▁network ▁compr ises ▁seven ▁tr aml ines : ▁six ▁lines ▁that ▁operate ▁daily , ▁and ▁a ▁sevent h ▁tram line ▁( Line ▁ 8 ) ▁that ▁oper ates ▁only ▁on ▁week days ; ▁an ▁e ighth ▁tram ▁route ▁is ▁operated ▁by ▁VB K ▁though ▁it ▁is ▁partially ▁owned ▁by ▁AV G ▁and ▁is ▁operated ▁as ▁part ▁of ▁the ▁Kar ls ru he ▁Stadt bahn . ▁ ▁All ▁daily ▁tr aml ines ▁run ▁during ▁the ▁day ▁on ▁week days ▁at ▁ten - min ute ▁intervals . ▁Line ▁ 8 ▁now ▁only ▁oper ates ▁once ▁or ▁twice ▁on ▁week days ▁as ▁a ▁school ▁tram , ▁thus ▁only ▁on ▁school ▁days . ▁Stadt bahn ▁Line ▁S ▁ 2 ▁runs ▁in ▁the ▁city ▁area ▁( R hein str ands ied lung ▁< -> ▁Re itsch ul sch lag ) ▁during ▁the ▁day ▁at ▁ten - min ute ▁intervals . ▁Services ▁operate ▁outside ▁the ▁city ▁limits ▁during ▁the ▁day ▁at ▁least ▁at ▁ 2 0 - min ute ▁intervals . ▁Add itional ▁Stadt bahn ▁services ▁are ▁operated ▁on ▁the ▁Kar ls ru he ▁tram ▁network ▁on ▁the ▁Kar ls ru he ▁model ▁by ▁Al bt al - Ver kehr s - G es ellschaft ▁( AV G ), ▁in ▁co operation ▁with ▁Verkehr s bet rie