A well-designed urban public transport policy provides significant benefits: ensures a more efficient transport system that reduces congestion and costs, and decreases the number of accidents and the environment impacts. Accessibility indicators are used by planners to assess the spatial effects of their proposals and to identify those areas requiring actions to ensure minimum conditions of service. They are also used in decision making on the implementation of new infrastructure projects or improvement of the existing ones. This research will first review the ICON indicator, which evaluates the connectivity of a location to the transport networks as a function of the minimum time required to reach the connection nodes of each network and the utility provided in these nodes. In the interurban ICON these networks include roads, railways, but also, ports and airports. ICON is being used in planning and in project appraisal to quantify in an understandable way the relationship between transport infrastructure and services endowment and variables that are spatially defined. But it has been seldom used in the urban environment context because its particularities introduce important methodological difficulties. Therefore the proposed research presents the adaptation of the ICON indicator to the public transport endowment of urban areas. The main objectives of the research are: the definition of a suitable URBan Indicator of CONnectivity (URBICON) providing a quantified spatial measure of connectivity to the transport networks, to integrate this indicator with other information (population, economical activity) and GIS tools in order to generate complex spatial indicators and to analyse the potential of these indicators in the planning process and in project appraisal. Implementing this ICON indicator in GIS tools allows, for instance, to produce a visual reference, on a map of the territory, of the most disadvantaged areas from the standpoint of its connectivity to the networks and, of the impact that the new transport projects would have on them. An application to the case of the city of Barcelona will be presented, considering the public transport endowment in the year 2004. The URBICON provides an easy way to detect the areas that were poorly covered by the public transport system in 2004. Some of these areas are already covered by new or improved infrastructures and services and others should be served by 2014. This possibly shows that the zones detected by the URBICON correspond to those where planners have somehow decided to improve public transport services. URBICON thus appears as a powerful quantitative indicator to support urban planning. This TFM presents the first part of the research, including the following points: research context and main objectives, review of the ICON concept, definition of the URBICON, its application to the case of the city of Barcelona, conclusions derived and further research.