16th International Symposium on Theory and Practice in Transport Economics : 50 Years of Transport Research Experience Gained and Major Challenges ahead These proceedings of the 16th International Symposium on Theory and Practice in Transport Economics sketch a broad overview of transport economics research since the inception of the ECMT in 1953 and map out the directions for future work. The 22 papers presented cover such topics as transport infrastructures contribution to economic growth modal split competition in the transport sector the need for a supra national regulatory authority charging systems and environmental sustainability.