Peter Davidson Consultancy Ltd

Census Matrix Tools

Everyone in the UK was in the 2001 Census, but not everyone made their trip to work. You can't afford to build matrices without 2001 Census Matrix Tools.

2001 Census Matrix Tools:

Department for Transport (DfT) commissioned Peter Davidson Consultancy Ltd to update the Census Matrix Tools with the new 2001 ONS National Census, the National Travel Survey and the Labour Force Survey so as to produce work trip matrices for transport planners and the result is Census Matrix Tools. The census is an important data source. However there are problems with using the 'raw' census data as follows:

  1. Census data table entries of 1 or 2 were rounded either up to 3 or down to 0 randomly
  2. When tables at census output area when aggregated to ward level they did not match-up with the ward level tables. Cross tabulations were also randomised in this way
  3. The census asked respondents to give their normal journey to work and on many days people did not make this journey. The census 'journey' is inconsistent with our definition of a 'trip'
  4. For many uses, the work trips need to be split by different types of household car ownership
  5. Census data is rarely used on its own and variances are needed to combine data sources

The 2001 Census Matrix Tools software overcomes all of these. It produces origin-destination matrices containing the number of trips to work from each home census output area to every workplace census output area in England, Scotland and Wales. (This is a much finer level of detail than the 1991 version, which only went down to ward level). Census output areas can be aggregated to Wards, Districts, Counties or Regions or can be grouped according to any user-defined zone combination. The output is a set of trip matrices representing any year between 2001 and 2003 which can be printed, tabulated, manipulated, put into a spreadsheet, transport database or model.

Trip matrices can be annual averages or for a neutral month. They can be for a neutral weekday, average weekday, Saturday or Sunday. They can be split by mode (e.g. car driver, car passenger, bus, train, tube, walk, cycle, motorcycle) or by car availability: (0 cars, 1 car in 1 adult household, 1 car in a 2+ adults household, 2+ cars). Trip matrices can be Home-to-Work or Work-to-Home. They are provided with their variance (index of dispersion) matrix so that they can be statistically merged with other trip matrices according to the DfT matrix merging methodology.

The census was 100% and is therefore a data source you can't ignore. The DfT's 2001 Census Matrix Tools software is set to be a standard reference for preparing LTP's and monitoring for best value. It has been supplied to DfT, SRA, TRL, many of the multi-modal studies, consultants, Local Authorities and others. It is available for PC's running Windows 2000 or above and is priced by DfT at-cost. We can also provide the matrices themselves. Contact our Census Matrix Tools project manager or visit our websites www.peter-davidson.com and www.transport-modelling.com or purchase on-line at www.visual-transport-modeller.com.

The 2011 Census Matrix Tools is currently being planned.