The Metropolitan cars were also the catalyst of change for their respective systems as the high-level boarding required all stations in the electrified zone to be rebuilt between 1966 and 1968, and the increased power demand forced the LIRR to update its third rail power supply from 650 V DC to 750 V DC to take advantage of the car's performance. On December 30, 1968, the M1s went into revenue service, with the first revenue train being an 8-car local from Babylon to Penn Station.
The Metropolitan cars triggered a shift in their respective systems, as high-level boarding necessitated the rebuilding of all stations within the electrified zone between 1966 and 1968. The increased power demand prompted the LIRR to upgrade its third rail power supply from 650 V DC to 750 V DC to accommodate the car's performance. On December 30, 1968, the M1s entered revenue service with the first revenue train being an 8-car local from Babylon to Penn Station.