How do bus stop displays work (Bucks)

[PeterC]

Locally in Bucks the displays on town centre bus stops are regarded as a joke. Sometimes buses aren't shown, sometimes the time to arrival will drop by 15 or 20 minutes in one go. The errors aren't consistent so I can't put it down to an error in how the routes and times have been entered.

Since discovering the real time map on bustimes.org I have checked this against the time and found that they are pretty accurate about the location of the buses. I have found, however, buses showing on the map with the wrong route number or supposedly travelling to the terminus that they are heading away from. The latter instance was the bus that I was waiting for and there was no countdown showing at the stop.

Is the local authority's system simply wrong or are they using a source other than the accurate GPS readings that bustimes have?

I am guessing that issues over buses going the "wrong way" are down to drivers not resetting route displays properly. The worst offending route terminates in loops at both ends so there is no obvious point where you can say that the outbound trip has finished and the inbound started.

 

[Contains Nuts]

The tracking feed to the RTI system is likely to be from the same source as Bustimes. What is more likely, and common in many areas, is that some elements of the TransXChange data that feeds the timetable data to the system is either wrong, incomplete or missing altogether.

 

[PeterC]

The tracking feed to the RTI system is likely to be from the same source as Bustimes. What is more likely, and common in many areas, is that some elements of the TransXChange data that feeds the timetable data to the system is either wrong, incomplete or missing altogether.

I think that I follow despite the jargon, however an error in the data would be expected to lead to a consistent error in the output. eg the bus would always be considered 20 minutes away at point X even though it is only 5 minutes drive away. What is observed is that the error isn't consistent, on one day the RTI suddenly jumps from 20 minutes to 5, on another the bus is shown as 15 minutes away as it pulls up at the stop.

Before seeing that accurate GPS data existed I assumed that the RTI location was based on a manual setting on the ticket machine. As mid-day services on local routes are largely used by pensioners who are not buying tickets the driver wouldn't necessarily need to set the location at each fare stage (something that I have seen some drivers do).

 

[Stan Drews]

The system (used to show the real time display) first needs to know the scheduled information. This has to match the scheduled data in the ticket machine (or any other alternative system within the bus) in order that the ‘actual’ can be compared with the ‘scheduled’, and the expected time at that location shown. It is very common for the systems not to match, which can be because the operator hasn’t sent an updated schedule to the local authority (LA), or that the LA simply hasn’t loaded the correct schedule.
The ticket machine generally relies on the accurate input of duty, journey number etc by the driver, so any errors with those, can also lead to incorrect real time displays.
It’s great when it works, but it doesn’t take too much for the gremlins to take control.