Dual gauge track in Columbus

[Myrtone]

If new rolling stock built for a network or line is a different gauge from the existing rolling stock, there needs to be dual gauge track wherever the old and new fleet share tracks. Dual gauge track may also be needed on a network if some parts get re-gauged while others continue to operate. If dual gauge track between any two standards is not possible, then it is not possible to convert any interconnected network without closing the whole thing, perhaps for an extended period of time.

[Myrtone]

Would the need to roll special rails for the dual gauge side add to the cost and complexity of converting existing Pennsylvania trolley gauge systems to standard? Could there be places, both in Pittsburgh and Philadelphia, where there is not enough clearence for dual gauge track, given that three-rail track means that the track centers of the two gauges are in slightly different locations?
I know there are no plans to change the gauge in either case, but could that be simply because it is not possible to change without closing some sections temporarily but for an extended period of time?