Ecological issues in traffic become more and more pressing as personal transportation is one of the greatest contributors of CO2 emissions. Means to help people reducing their ecological impact are urgently needed. To answer this need Peacox provides travellers with personalized multi-modal navigation tools that allow, help and persuade them to travel and drive ecological friendlier. To convince users in making more sustainable travel choices Peacox will enrich navigation systems with innovative approaches and features:•\tPeacox integrates automated travel mode detection based on real-time GPS data into the trip planning thereby minimizing the need for explicit user input.•\tPeacox has the capability to automatically detect users' trip purpose through the analysis of behavioural patterns allowing tailoring trip suggestions to these purposes.•\tPeacox builds dynamic user models allowing personalizing recommendations based on prior trip choices and individual preferences.•\tPeacox develops advanced door-to-door emissions models that provide accurate feedback on the ecological/carbon footprint and exposure levels in planning as well as during travelling and car driving activities.•\tPeacox develops and utilizes persuasive interface strategies to give feedback about the ecological impact of individuals' behavior as well as make the ecological friendliest behavioral pattern visible and attractive.The system will be developed in two iterations following user-centred and agile design approaches, and extensive field trials in Vienna and Dublin will ensure high quality and impact of the developed Peacox system. The Peacox consortium unites expertise from navigation systems, transportation sciences, environmental modelling, artificial intelligence, persuasive technology, human-computer interaction to software development.