The Polis Conference is a major platform for cities, metropolitan areas and regions to exchange on their transport challenges. High-level plenary sessions are complemented by technical sessions showing innovation in policy and practice across the transport spectrum. 2015 Annual Polis Conference on "Transport innovation for sustainable cities and regions" took place on 19 and 20 November 2015 in Brussels. COSMOS presented “An open platform for transport data in Madrid”, demonstrating the development of an open platform through which the various elements related to transport and traffic are made available to citizens and businesses under a completely new and innovative model.