I thought I saw further upthread that someone involved in bustimes.org was a member here, or if not, perhaps someone else knows. I've had cause to wonder about how Bustimes shows the tracking data as to which journeys the service operated on.
Out bus watching on Tuesday, I saw a bus be pulled off one service to cover an otherwise missing journey on a less frequent service. It tracks it has having started both journeys. On another service which has 20-or-so minutes layover, buses are often tracked "leaving twice" - once shortly after they arrive, once shortly before (or, being Arriva, after!) they are due to leave. It appears the tracking feed is from when drivers enter the journey details on the ticket machine, rather than necessary anything to do with the timetabled time, and in that latter case, the second departure is when the driver restarts the engine after layover.
If anyone wouldn't mind confirming, that would make my deductions an awful lot easier, especially on services where one bus arrives just as, or at the same time as, another bus leaves (as is the case with one 10-minute service that has a 9 minute layover)!
Also, I presume it is intentional that you can access the timetable tab from the list of vehicles used on a service that particular day, but not the vehicle tab from the timetable, to avoid confusing the "normal people" (as it is, of course, first and foremost a public site)?
Thanks for anyone's input!