This project provides upgrades to BART’s 34.5kV subtransmission system including replacement of the left and right circuit cable sections between RCP traction power substation (TPSS) to RPD traction power switching station, RPD to RCN TPSS, RCN to RRI TPSS, RRI to future RYE TPSS and RYE to RRY TPSS. Concurrent with the subtransmission circuit replacement, installation of isolation disconnect switches at RCP, RPD, RCN, RRI, the future RYE site, and RRY substation locations. Additionally, 288 and 144 strand fiber optic (FO) cable is to be installed connecting the train control rooms (TCR) at all passenger stations from RCP to RRI and to the Richmond Yard TCR.