Greenhouse gases emissions are a major contributor to global warming and climate change, with traffic congestion being one of the major contributing factors to growing CO2 emissions. The OPTI-TRANS (Optimum-Transportation) project aims to create a Mobile GNSS application and backend platform which will provide a commuter with the ability to plan a trip in an efficient manner. It will enable the use and sharing of public and private transportation modalities by combining information from the public transport authorities, private fleets and other privately owned vehicles (e.g. car poolers). The optimum route/transport combinations will be displayed on the commuters mobile terminal based on location, destination and preferences. The OPTI-TRANS platform will also encompass routing and timetable information from all modes of public transport in order to provide to the user the alternative of utilizing a multi-modal transportation solution the journey. This will encourage commuters to restrict the use of private vehicles, contributing to a safer and cleaner environment.