“…The popularity of these concepts resulted in numerous empirical studies investigating the influence of the built environment on travel behavior, thereby statistically controlling for differences in socio-economic factors such as income, car ownership and household composition (Bagley and Mokhtarian, 2002;Chen et al, 2008;Mokhtarian and Cao, 2008;Van Acker et al, 2011a;van Wee et al, 2002). However, more recent research has shown that within homogeneous socio-economic groups different travel behavior can still be observed, indicating that not only 'objective' (or hard) variables, like the built environment and socio-economic factors, influence travel behavior, but that 'Subjective' (or soft) variables should also be included in the analysis (Mokhtarian and Cao, 2008;Van Acker et al, 2011b;van Wee et al, 2002). According to various studies, personal lifestyles and attitudes have an important impact on travel behavior (Anable, 2005;Bagley and Mokhtarian, 2002;Kitamura et al, 1997;Mokhtarian, 2005a, 2005b;Steg, 2005;Steg et al, 2001).…”