For more information on data sources and other articles see:
Valuing Household Transport in the UK
http://www.statistics.gov.uk/themes/economy/Articles/General/extracts/dec01.asp#valuing
Department for Transport, Local Government and the Regions (DTLR)
http://www.dtlr.gov.uk
Labour Force Survey
http://www.statistics.gov.uk/ssd/surveys/labour_force_survey.asp
National Travel Survey
http://www.statistics.gov.uk/ssd/surveys/national_travel_survey.asp