To contribute to roads maintenance and to reduce pollution, congestions, an expanding number of countries in the world are adopting Road User Charging solutions. These solutions are increasingly making use of the Global Navigation Satellite Systems (GPS, GLONASS, etc.). In this paper are described the technical key challenges to be addressed when implementing a GNSS based Road User Charging system as well as first feedbacks from implementation experiences of Thales Alenia Space. After recalling the background, localization technical challenges and billing schemes are listed; Then technical implementation for localization and associated tradeoffs are described with an additional zoom on extracting toll events from positions. The main technical challenges for GNSS-based solutions in land applications with a certain level of criticality (since invoicing depends on the position) result from the need to get a certain level of confidence in the estimated position while facing signal propagation issues such as multipath, fading, or masking, as well as potential interference and spoofing conditions. The paper details how receiver technologies based on hybridization techniques can address these conditions. Last but not least, implementation challenges are described together with implementation results.

Keywords: GNSS, GPS, M2M, road user charging, electronic fee collection, tolling, pay as you drive, spoofing detection, its, authentication. vehicle miles travel FEE.