Local authorities have a growing need for information on mobility, mainly due to the PDUs, Plan de Déplacements Urbains, or Urban Transportation Plans. Household travel surveys provide essential information on mobility. New challenges facing territorial authorities mean that existing resources must be adapted. Certu monitors local projects with a view to building on the experience and expertise gained, and also circulates the results of household surveys as widely as possible. Discussions and actions undertaken in the interests of sustainable have led Certu to work with European partners on improving the methods used to collect data on mobility. Surveys on urban and non-urban public transport services add to our knowledge of mobility by improving knowledge of the transport services available and help improve our understanding of changes and future prospects.