This paper studies the effectiveness of urban cycle lanes, with cycling being one of the most common practices for promoting sustainable mobility in urban areas. Despite a growing interest, the use of cycling in Italian cities has not gained a large consensus yet. Nevertheless, the presence and the extension of cycle lanes are considered as quantitative indicators for measuring the livability of cities. Actually, the lack in assessing the global quality of cycle networks asks for a major attention in the definition of these indicators. Starting from these considerations, the present study tries to propose a different approach to assess the real effectiveness of an urban cycle network. By defining some typological clusters of anomalies (dyscrasias) that can impede a safe and comfortable use of bicycles, the study achieves the definition of a method to evaluate the real effectiveness of an urban cycle lane. The case study of Naples represents a first trial both to check the method and to assess the state of the existing urban lane in order to verify its effectiveness.Sustainability 2020, 12, 2321 2 of 23 urban lanes dedicated to cycling, considering their actual effectiveness. In fact, cycle paths in a city are usually measured only in terms of length, regardless of quality and effectiveness of the overall network. Geometrical (width, slope, etc.), construction (type of pavement), functional (reserved for bicycles or cycle-pedestrian), safety (visibility, signage, etc.), and connection (continuous network vs isolated and separated cycle lanes) characteristics significantly influence the perception of the cycle network and the propensity to use the bicycles. In this paper, we propose a methodology to "weigh" and measure a cycle network considering its characteristics; indeed, two cycle networks that have the same mileage development, even in cities that are similar in size and mobility system, can have a completely different impact on the diffusion of cycle use, according to their characteristics.Therefore, the main objective of this study is to propose a method for measuring an equivalent length of the cycle network able to express its usefulness in urban areas. It stems from the need to investigate why the growing number of cycle paths does not lead to a proportional increase in urban cycling in Italy. In fact, despite an increase in urban cycle paths, to date the use of the bicycle is still low in comparison with many European countries (see Section 2). The authors' opinion is that such low interest could be due to some structural deficiencies that may negatively influence users' perceptions. These can also be thought of as some conditions that affect both the physical structure of the lane and the perception of it as not comfortable or dangerous to use. Actually, to be considered as viable and perceived as reliable, the cycle path must have at least two main features [3,4]: an uninterrupted track (continuity factor) and connections among each section of the lane and between the lane and the urban places (connect...