In part three of this three-part series, I explain the ways in which layouts can host modern transit and modeling-relevant operations, giving examples for layouts small, medium, and large for how to realistically and entertainingly model walking, bicycling, busses, streetcars, trams/straßenbahnen, light rail, stadtbahnen, tram-trains, DMUs, heavy rail subways, schnellbahnen/RERs, intercity rail, long distance/night trains, High-eR Speed Rail (HRSR), and High Speed Rail (HSR).