Estimates of population movements (human mobility) have traditionally been provided from relatively expensive sample surveys of individuals. What other data sources might now be available to replace or supplement survey data to provide insight into population movements on a daily basis? How could these sources be exploited? Please consider the types of application and analysis to be carried out, how this supplements survey data, and how the results would add to existing understanding of time use in the population. You may make plausible assumptions about the type of data available. You can assume that the data is available in consistent and well-documented format.