This paper investigates the factors that are implying a change in the attitudes to mobility of Millennials in Barcelona. For this purpose, a web-based survey has been designed and conducted to detect revealed-preferences and attitudinal aspects of transport users. A descriptive analysis of the data has shown that Millennials are delaying their lifecycle milestones in comparison to previous generations, that they own less private vehicles, and that they travel more and for longer than any other user. The motivation of the paper is to find the latent factors behind those new travel patterns. First, different factor analyses have been tested to show a methodical way to correctly extract the factors of multiple attitudinal items. Then, the selected factor analysis has been conducted for each population segment (i.e. Millennials and older adults). It has been found that the structure of the factors has been generally maintained among generations, with slight variations in the way in which each group defines and perceives the same factors. In addition, there is a clear willingness among Millennials to change their transport mode. Second, factor analysis has been tested through estimating different mode choices models, to evaluate the relative contribution that the extracted attitudinal factors have on explaining behaviors over the choice of Millennials. The model has been better adjusted by including the extracted attitudinal factors. In this case it is striking that the factors related to time sensitivity and the use of time are more explanatory than the time spent travelling itself.