This report describes the project "Demonstration traffic with TramTrain" which was performed over the period April-June 2006 with the TramTrain Regio Citadis. Traffic was carried out on the sections Linköping-Kisa, Linköping-Åtvidaberg and on the tram network in Norrköping. The vehicle was also demonstrated in Finspång and Västervik where shorter journeys were made. Traffic was also carried out on the section Göteborg-Älvängen, on the tram network in Göteborg, the section Helsingborg-Åstorp and the section Lund-Eslöv. The objective of the project was to show, in a concrete manner, the properties of TramTrain and its potential to political decision makers, civil servants and executives within public transport, but also to the public at large.. The project had the character of a "triple helix" project in which a large number of partners participated. The increase in knowledge and experiences which was achieved by putting the vehicle into traffic could not have been generated other than through a practical demonstration. The project has demonstrated how different actors with different cultures and value systems can cooperate in one and the same project. The report describes the planning process for the project and the practical execution of the demonstration traffic from the Östgöta Region, Göteborg, Helsingborg and Lund. The views of travellers via a questionnaire survey and views put forward during interviews with the steering and reference group are also given.