Statistics User Forum

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The Statistics User Forum (SUF), supported by the Office for National Statistics, aims to be the strategic voice of users of official statistics. The Forum acts as an umbrella organisation for user groups, each of which covers a particular area across the spectrum of official statistics. Through the Forum we enable open and constructive dialogue between users and producers of official statistics and encourage communication across the user community.

DfT Journey Time statistics

  • 1.  DfT Journey Time statistics

    Posted 15-12-2017 10:58
    D​​ear colleagues
    Has anyone else been having trouble making sense of the latest set of published Journey Time statistics (Journey time statistics - GOV.UK
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    Journey time statistics - GOV.UK
    Information and statistics on journey times.
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    The data for my authority looks very odd, especially the car journey time data.  While we have some rural areas, we also have big urban areas like Eastbourne.  My interest was piqued when I noticed that, in contrast to the 2014 data (100%), only 97% of Eastbourne residents could apparently access a Town Centre by driving within an hour in 2015.  Now the traffic in Eastbourne can be terrible but I thought this was unlikely, so I started to look at other parts of the data and noticed that apparently only 90% of people living in the City of London can access a town centre within an hour by car, which is more obviously nonsense.  When I started to delve further into the data I found that in one LSOA in Eastbourne, located around 200m from a large Asda superstore (and with plenty of smaller food shops around too), the data suggests that only 12% of people can drive to a food store within an hour - 88% of people in this LSOA in a large urban area cannot drive to a food shop within an hour!
    And in the City, in City of London 001A (around the Barbican and Museum of London), only 81% can drive to a food shop within an hour.  Just to clarify - the data says that 19% of people in the City of London could not reach a food shop within an hour by car (or a bicycle).

    I have raised the issue with DFT (Subnational stats) and been told that they have been through the data in detail and that 'the methodology and calculations are correct ...It looks as though it's an issue of changing populations and an artefact of the methodology we use, and we are working on a more detailed understanding of this and some guidance for users of the statistics'

    I use TRACC (the software they are using for the journey time data) and know that it can produce some odd results, but would suggest that if the results presented look like nonsense, it will be difficult to convince our customers that the data is useful or  that we should be using these results to shape transport and infrastructure policies.  Perhaps the team need to raise the issue with Basemaps to find out what would be causing these anomalous results.

    The webpage says 'All of the statistics published are official statistics. The department's view is that all statistics which are not designated as national statistics are robust and have been produced to a suitable standard.'

    These numbers do not give me confidence that the standard is suitable.
    I welcome the thoughts of people in this group.  Merry Christmas.

    Lenna Santamaria
    Planning Research Officer
    East Sussex County Council