Watch your Emissions: Persuasive Strategies and Choice Architecture for Sustainable Decisions in Urban Mobility

Persuasive technologies are suitable for encouraging green transportation behaviour towards CO2 emissions reduction. For example, such technologies can guide and support users in finding trips that cause low emissions and in the long term change their behaviour and habits towards more sustainable transport decisions. In this paper, we focus on persuasive strategies supported by a choice architecture approach and incorporated in a smartphone application, aiming at providing urban travellers with a solution that will influence them to consider the environmental friendliness of travel modes while planning a route. We focus specifically on the persuasive strategies of Reduction, Tailoring, Tunnelling, Cause-andEffect Simulation and Suggestion. The choice architecture approach leverages routing options and results of a commercial routing engine in order to provide proper default options as well as filter and structure the results according to user preferences and contexts while emphasizing environmentally friendly routes. Our approach is integrated in a route-planning assistant for everyday use that is implemented for Android mobile phones and follows a client– server architecture. An evaluation with 24 participants using the system for 8 weeks showed good acceptance of our approach, increased environmental impact awareness, and qualitative comments also conveyed instances of behavioural change.