Ever been at a bus stop tracking your bus on a mobile app only to see it disappear rather than arrive?
The developer of real-time travel application TripView thinks he knows what's happening with these so-called "ghost buses".
Most transport apps use GPS data to track buses as they travel along their route.
The system relies on both a device in the bus and real-time information from customers tapping on and off with their travel cards.
Regular bus timetable information and a log of when drivers sign on at work also helps determine the location of buses and when they should arrive.
Collectively this data - in NSW - is the Public Transport Information and Priority System.
The PTIPS data - provided by Transport for NSW - is estimated to be 99 per cent accurate for arrival times, a spokeswoman told AAP.
But sometimes things go awry.
If GPS data isn't available - for whatever reason - some travel apps revert to using old-school timetable information. Hence you may see a bus approaching when it doesn't actually exist.
It may have been cancelled or the bus itself switched off when the driver takes a break, for example.
Similarly, if travel-card consoles aren't working. apps may again switch to showing estimated arrival times.
"From a TripView perspective, a bus should only disappear from the map if there is no longer GPS data for that bus on Transport's real-time data feed," TripView developer Nick Maher told AAP.
"I sometimes receive reports of this where it turns out that the bus in question wasn't providing any real-time data. In this case, TripView would have just been showing the scheduled time."
A Transport for NSW spokeswoman acknowledged some external apps don't always use PTIPS data.
"At times they may apply their own logic to interpret (PTIPS) data ... which can in turn cause inconsistencies in tracking information," she told AAP.
Share
