In this paper some of the advantages and benefits of the cycling use are presented, and some factors that influence its utilization are analysed. In particular, the study is focused on the barrier elements and, more specifically, in the structural barrier factors. Further on, more than 70 kilometres of bicycle network in several cities of the region of Castile and Leon (Spain) have been analysed, in order to see their potential influence on the use of the bicycle. From the results of this analysis some recurring problems emerge and make us identify that the total length of the bicycle network is not so important as the number of destinations and completed itineraries that can be reached in an effective and safe way.