This study started with an initial inquiry on older adults’ out-of-home mobility carried out in four European cities in 1995 (Mollenkopf et al. 2004a). The German parts of the investigation—on which the present study is based—were carried out in the cities of Mannheim (western Germany) and Chemnitz (eastern Germany). Both of them are middle-sized industrial cities with diversified settlement structures and public transportation (tram and bus lines) as well as rail connections and national roads. The quantitative part of the study included N = 804 persons aged 55 years or older, which resulted from a randomly drawn sample of addresses from the population registers of the Municipality Registration Offices of Chemnitz and Mannheim. Thirty-five of the participants were selected for additional in-depth interviews because they showed a particularly low or high degree of mobility. Five years later (2000), 271 respondents from the original sample could be reassessed in an initial follow-up as part of the project entitled “Mobilate: Enhancing Outdoor Mobility in Later Life” funded by the European Commission in the Fifth Framework Programme (Programme Area no. 6.3, Project QLRT-1999-02236). The comparative findings of this international and interdisciplinary project, including data from Finland, Germany, Hungary, Italy, and the Netherlands, have been published elsewhere (e.g., Mollenkopf et al., 2003, 2005, 2006; Mollenkopf, Ruoppila, & Marcellini, 2007). Another 5 years later (2005), a third assessment took place in the German cities and resulted in N = 82 participants, or approximately 30 % from the first follow-up and 11 % from the original sample. Hence, the present study covers these participants over a 10-year period.
Well-trained interviewers from the USUMA research institute (Berlin) conducted the German interviews in 1995 and 2000. The 2005 Chemnitz interviews were also conducted by USUMA interviewers, and the interviews in Mannheim were conducted by the project staff.