Boulard, CécileCastellani, StefaniaColombino, TommasoGrasso, Antonietta2019-04-232019-04-232019In the context of addressing global warming issues, one of the possible approaches is to provide individuals with tools that support change toward greener practices, as for example around commuting. This paper illustrates a study that we conducted on the effectiveness of self-tracking of commuting data where participants received daily feedback on the financial costs and CO2 emissions associated to their mobility practices. In the results, we describe situations where users do not accept the data and the models utilized to represent them, highlighting a limitation that diary instruments (and underlying models) of this type would have in supporting people to question and possiblychangetheirmobilitychoices. Onthebasisofthestudyfindings,wealsodescribe a new model aimed at overcoming some of the limitations that the study showed, in particular by better connecting the individual environmental impact with the collective one.enText/Conference Paper10.18420/ecscw2019_ep122510-2591