East Japan Railway Co. said Tuesday it will carry out test runs of automated trains with passengers aboard on Tokyo’s Yamanote loop line for two months starting around October. JR East has been testing the automated system on out-of-service trains on the line — one of Tokyo’s most congested — since 2018, and the operator intends to implement the technology around 2028. The move is part of measures to stem a possible shortage of drivers amid the nation’s shrinking population. When using the automated operations system, drivers simply push a button to speed up the train to depart. It also auto…