As part of the CEDR 2013 Traffic Management research programme, the project “UNIETD” addresses “Understanding New and Improving Existing Traffic Data”. The primary objective is to guide national road administrations’ use of third party data such as crowd-sourced, social media and floating vehicle data in place of traditional infrastructure-based techniques. Existing methods for quality assessment of floating vehicle data have been compared and assessed, and a new methodology has been developed to address drawbacks of existing methods. The relevance of social media content for traffic management has been assessed. Geotagged tweets can be used as an additional source of traffic speed. Tweets also contain textual content that is relevant for traffic management, and the relevance of tweets was automatically classified and assigned a relevant category using ontology designed for this purpose.