There is an interesting possiblity to add randomness into the game with the request stop feature. Each time you run a service, as you approach a station the game could do a random draw to see if a passenger will request a stop. If they do the driver is notified and has to make the stop and the timetable adjusts dynamically. This would mean that service routes are randomised in terms of how many stops there will be and at which stations. If service mode is considered too difficult, then perhaps a scenario could have random stops, like one of the LGV scenarios had random weather.
The TS classic routes already do this - a scenario marker on approach to a station will either trigger the request signal or sound the bong bong in the cab (and sometimes both) at random - I'd be surprised if the TSW version didn't have this implemented.
