travelinedata


How is the quality of the data measured?

There are three measurements Completeness, Timeliness and Accuracy.

These measures have been devised by the traveline Data Management Working Group and agreed by the Board. They are measured on a regional basis though some regions give a breakdown for parts of their region.

The figures are calculated by the regional coordinators and submitted for publication nationally.

Completeness

This measure is a percentage of the total registrations, routes or timetables that are in the journey planner at a particular point. The date of measurement is usually midway between the BT questionnaire response dates.

At the DMWG meeting on 14 December 2005, slight amendments were made to the data definitions agreed on 9 March 2005:

NOTE: Defined Minimum. All registered services up to AREPs but does not have to include: school service if registered and open to the public; school service registered but with ticket restrictions; school service not registered; demand responsive service; park and ride service; registered road work deviations; temporary service for special events; Megabus or EasyBus service; National Express local sections; community transport section 19 not registered; services with restrictions; free services not registered (eg Supermarket); tram route even though not registered; ferries, Underground and light-rail services.

The standard is 100%. Therefore it is expected that a region should have all the timetables in their system.

Timeliness

This measures whether data has been entered sufficiently in advance of the change date. It also takes account of whether the local authority has been notified of the final timetable 56 days in advance of the service change in accordance with the PSV regulations or PSV regulations (Scotland).

There are 4 key dates which should be recorded at the point of entering the registration into the data system:

These dates are sufficient to determine the standards and targets in any given period. At the DMWG on 14 December 2005 (DMWG/016), it was agreed that there should be one standard and four associated provisional targets: Although the measures are normally listed in the order given above, it may help to see them categorised in the following table:

Timeliness measures (and targets) Of total Available by start date Available with 14 days notice
All Registrations number % (>60%) % (>50%)
Received with 28 days notice number % (>80%) % (>75%)
Received with 56 days notice number Not Used % (100%)

See an example of how to calculate the timeliness measures

Can you enter data before the registration is received?

This will depend on the systems and policies in place in your region or authority. Nevertheless there are some good reasons for doing this if it is possible:

In using non registered data you will be taking greater responsibility for information given to passengers. For some people this is sufficient reason not to use such data. Others are able to use their experience and expertise to ensure that passengers get a much better information service.

These issues are closely associated with the "Look Ahead" period in the journey planners. Most journey planners allow passengers to plan further ahead than the 56 day registration period and all the regions data is in Transport Direct with at least a two month look ahead period. With processing time and a high number of short notice registrations, timetable data based only on registrations is unlikely to reflect all the known changes.

If there is a long look ahead it is important that the internet journey planners and call centres advise passengers to recheck their journey information nearer to the time of travel.

Go to an example of how to calculate the measures

The Reporting Period dates are listed on the list of meetings dates.

Accuracy

There is no national agreed approach to this yet. However regions are encouraged to record information of errors or failures that are discovered once the data is entered.

The data processes vary between regions and different views may be taken as to what is the point of entry of the data. Although accuracy can be improved if downstream checking of the data causes it to be returned and corrected, this can result in a minor error causing a whole service change to be lost with consequences for timeliness. Therefore it may be better to use quality assurance processes to supply the data to a high standard and assume it meets the timeliness checks with any problems on subsequent testing regarded as accuracy errors.


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© Traveline 2011, Last updated: 26 May 2011