side ▁third ▁rail ▁used ▁by ▁most ▁met ro ▁trains ▁and ▁some ▁main - line ▁rail ways , ▁A PS ▁does ▁not ▁pose ▁a ▁danger ▁to ▁people ▁or ▁animals ▁and ▁so ▁can ▁be ▁used ▁in ▁ped est rian ▁areas ▁and ▁city ▁streets . ▁ ▁A PS ▁uses ▁a ▁third ▁rail ▁placed ▁between ▁the ▁running ▁rails , ▁divided ▁elect r ically ▁into ▁ten - met re ▁rail ▁segments ▁with ▁three - met re ▁neutral ▁sections ▁between . ▁Each ▁tram ▁has ▁two ▁power ▁collection ▁sho es , ▁next ▁to ▁which ▁are ▁anten nas ▁that ▁send ▁radio ▁signals ▁to ▁energ ise ▁the ▁power ▁rail ▁segments ▁as ▁the ▁tram ▁passes ▁over ▁them . ▁At ▁any ▁one ▁time , ▁two ▁consecutive ▁segments ▁under ▁the ▁tram ▁will ▁be ▁live . ▁ ▁Use ▁in ▁Bor de aux ▁Modern ▁ground - level ▁current ▁collection ▁was ▁pione ered ▁by ▁the ▁Bor de aux ▁tram way ▁in ▁France . ▁The ▁public ▁had ▁assumed ▁that ▁the ▁new ▁system ▁would ▁use ▁a ▁traditional ▁condu it ▁system , ▁like ▁that ▁of ▁the ▁Bor de aux ▁tr ams ▁which ▁ran ▁prior ▁to ▁ 1 9 5 8 ▁and ▁object ed ▁when ▁they ▁learned ▁that ▁it ▁was ▁not ▁considered ▁safe ▁and ▁that ▁overhead ▁w ires ▁were ▁to ▁be ▁used ▁instead . ▁F acing ▁compla ints ▁both ▁from ▁the ▁public ▁and ▁the ▁French ▁Ministry ▁of ▁Culture , ▁pl ann ers ▁developed ▁A PS ▁as ▁a ▁modern ▁way ▁of ▁rep lic ating ▁the ▁condu it ▁system . ▁ ▁A PS ▁was ▁developed ▁by ▁In nor ail , ▁a ▁subs idi ary