This paper presents a study related to the theme of sustainable urban mobility with a focus on the factors that contribute to the development of a city s potential in regards to the use of the bicycle as a means of urban transportation. For this study, changes in technology over the past centuries, in particular the development of the automobile industry in the postwar period, were examined and main impacts on the city and their reflections in contemporary social dynamics were identified. Based on this, an overview of the benefits of the bicycle as a means of urban transportation was defined employing four case studies from around the world, each with its own peculiarities: New York, London, Bogota and Copenhagen. From these examples, several key factors that influence a city s potential for the use of the bicycles as a means of urban transportation were extracted. Using these factors as a foundation, a comparative study of Rio de Janeiro was performed employing seven different categories of analysis such as: the rate of motorization; the weather; the safety and quality of bicycle paths; integration with other means of transportation; the distances to be traveled; terrain and the urban form; and incentive policies. The impact of the rate of change on the social environment, coupled with the territorial impact of transportation infrastructure, has been gradually reducing, fragmenting and marginalizing the behavior and available space for the pedestrian. As a general consequence, statistics and studies tend to disregard non-motorized transportation as a part of the overall system. This contributed greatly, as pointed out by GRAHAM and MARVIN (2001), to the social drain in transportation planning which initiated in the 1970s. Thus, it is possible to state that the way we commute in a city directly influences not only our perception of the area, but also the way we interact socially. This assumption reinforces the centrality of mobility as a fundamental aspect of a healthy urban environment. The individual who rides in a car does not perceive the important aspects of the urban environment. The car distances the individual from the surroundings and creates a controlled and isolated environment for the passengers. Aspects that define the ambiance of a city such as temperature, sounds, smells and urban textures, go unnoticed when commuting within isolated environments. The same applies to subways, trains and buses, whereas just the opposite occurs when we commute on foot or bicycle. Consequently, the reduction of public space is directly related to the process of technological acceleration, which occurred mainly during the twentieth century, but that began a few years earlier at around 1870. Accordingly, a paradigm shift in transportation planning has become essential. Access to diverse means of transportation, including the bicycle, needs to be promoted. In this context, the use of the bicycle, as a more efficient and affordable means of transportation, has been gaining more importance in urban centers by being able to serve as a complementary infrastructure to the existing mobility network and increasing the penetration in the territory. In addition, the bicycle is an inclusive means of transportation, when we take into account the low investment and maintenance costs, making it widely affordable and highly efficient. However, when analyzing the need of a transportation policy focused on sustainability, we realize that the use of the bicycle as a means of effective transportation has been lacking over the years in Brazil. This discernment becomes clearer when we analyze some of the European cities where bicycle use was amplified and maintained, both on the local and national level, through deliberate action. Although enormous potential to increase bicycle use in the city of Rio de Janeiro does exists, this can only be achieved through the development of a coherent approach. If we take the other main metropolitan regions into consideration, the Greater Rio area has the sixth largest motorization rate in the country following Curitiba, São Paulo, Distrito Federal (DF), Porto Alegre and Belo Horizonte. This is extremely significant. Not surprisingly, the motorization rates of London, Copenhagen and New York are also below their national average. In other words, a motorization rate below the national average could represent potential for the bicycle as a means of urban transportation. Another important factor, the weather, was considered. However, periodic data from cyclists in Rio de Janeiro does not exist making it difficult to assess any variations. In general, for the most part of the year, the weather for biking in the city of Rio de Janeiro is usually favorable. Nonetheless, the summer months are extremely hot and humid. Still, a policy that encourages companies to build changing rooms for employees could be an important incentive for the use of bicycles in the city, even during the hottest times. As previously mentioned, the quality and efficiency of a biking infrastructure is not measured by its length. For example, the extension of the existing network in Rio de Janeiro is comparable to Bogota and Copenhagen; however, its efficiency falls short of the above-mentioned examples. In addition, a relationship does exists between the number of cyclists and the implementation of measures that control traffic speed and prioritize safe, fast, and comfortable access, while at the same time, respect the rights of the cyclists. In Rio de Janeiro, the current infrastructure for cyclists is confusing and inconsistent, ranging from excellent bicycle paths, which serve mainly for cycling as a leisure activity, to precarious pathways that put the riders safety at risk. This in turn generates distrust in regards to the infrastructure and the general functioning of the cycling grid. The bicycle paths around the Lagoon and along the edge of the South Zone are the best examples of well-marked and maintained bicycle paths, while the cycling infrastructure of Botafogo, for example, is confusing, discontinuous and deprived of maintenance. The possibility of using the bicycle in combination with other means of transportation greatly enhances the rider s reach. In Rio de Janeiro, this is still an aspect that is underdeveloped. The bike-sharing system, located almost exclusively in the south zone of the city, has been making strides but still has its glitches. In addition, the use of the bicycles during the week is only permitted up to 21:00, while the use on weekends and holidays has no restrictions. This reinforces the stance of the City Hall and the concessionaires that the bicycle is used more for leisure rather than transportation. From the cyclist s point of view, the distances in Rio de Janeiro are generally shortened. However, the high temperatures during the summer months can reduce these distances to a range of 2 km and 8 km, but the bicycle, as compared to other modes of transportation, can serve as means of transport for shorter trips. In addition to these and other factors, Rio de Janeiro has one crucial factor that stands in the way of implementing an efficient cycling grid: the urban form of the city that is often determined by its terrain. This directly influences the street layout of the city, creating difficult constrictions, as for example, in the case of Botafogo. Aspects involving public policy, regulatory bodies and public awareness also have an impact on urban cycling indices. Municipal Law No. 4,678, which encourages the use of bicycles as a form of urban transportation, establishes overall objectives by compiling a series of good ideas, but lacks solid guidelines regarding the measures to be taken to ensure its execution. Bicycle use incentive policies should be based on studies and technical reports that can quantify the benefits of cycling as a means of urban transportation so that the results of implemented projects can be evaluated and measured. The analysis and monitoring must be executed on a regular basis in order to build a reliable database to assist in decision making. Setting of numerical goals and evaluation of project results was extremely effective in the cases presented. Despite the potential of the city, the reduced quantity of data available to serve as a basis makes the analysis of any future project very difficult. Unlike what takes place in Copenhagen, London, New York and Bogota, this lack of data makes it very difficult to understand the present situation and to prepare a strategic plan based on numerical targets. For example, the government of the city of Rio de Janeiro has few channels for the observation and monitoring of data on non-motorized transportation. This makes it difficult to establish goals and deadlines for improving the infrastructure. We are aware of the problem but do not know the exact cause. We must invest in research and diagnostic tools that allow, over time, for the consolidation of a database that is reliable and easy to access. There is insufficient research and data on traffic accidents involving cyclists and on the economic impacts of the industry that revolves around the bicycle. There is a lack of cyclists associations and an absence of specialized research institutes and transportation department data that effectively considers the bicycle as a means of transportation. Planning, implementation and evaluation of results is crucial in order to progress in the construction of bicycle paths and to encourage cycling as a means of transportation. However, this is a challenge in the city of Rio de Janeiro, mainly due to the lack of collection and systematization of data collected. The potential to transform the city through the use of the bicycle as a means of transportation does exists, but is not taken advantage of.