this paper contributes to the literature by providing new behavioral insight to improve policy measures that promote the adoption of autonomous systems of collective navigators as promising instruments for reducing urban traffic congestion and the related level of emissions, fostering the ecological transition by larger adoption among consumers of sustainable modes and choices of transportation. We contribute by the implementation of a laboratory experiment in which we adopt an original variant of the threshold public good game, designed to analyse the presence of externalities both in terms of congestion and CO2 emissions and to evaluate the behavioral response of individuals in front to the possibility to be driven toward the optimal social welfare in presence of heterogenous mobility costs. To the best of our knowledge, our design represents a novelty in the threshold public good game literature. Additionally, the discussion of the results of the experiment can provide interesting insights both for transportation policies and environmental ones.