The 4th European 'Transport Research Arena' (TRA) Conference, will be held in Athens, Greece, 23-26 April 2012, hosted by the Greek Ministry of Infrastructure Transport & Networks and supported by the main transport industry stakeholders in Europe: the Conference of European Directors of Roads (CEDR), the European Commission (EC), the European Road Transport Research Advisory Council (ERTRAC), the European Rail Research Advisory Council (ERRAC), and the European Technology Platform Waterborne (WATERBORNE).