@wild mary posted:
Additionally no special wiring is necessary with AC for reverse loops.
It's the three rails, not the AC, that eliminate the need for special wiring for reverse loops (as well as for wyes and turntables and any other track arrangement that turns trains around).
DC on three-rail does not require special wiring: Frank Ellison's Delta Lines was powered with DC and used outside third rail. Frank advocated three-rail over two-rail because of the complications in wiring two-rail.
The prototype (full-size trains) also use third rail or catenary which is electrically equivalent to a third rail. Prototype electrification uses both AC and DC.