Configuração e trajeto: adequação da configuração viária ao ciclismo urbano

Abstract

This work addresses relations between topological accessibility of the street system and bikeability, focusing on the city of Natal, northeast Brazil, as a case study. Bikeability is understood here as the set of qualities in the urban environment that are favourable to cycling. The main issue of how the urban form facilitates or hinders cycling as a transport mode was investigated through morphological and phenomenological approaches. Space syntax analysis was applied to investigate effects of the street configuration over the nature of cycling routes whereas the cyclists’ profile and demands in the city were investigated by means of surveys and interviews. The topological accessibility of Natal’s street network was quantified through linear representations and the resulting data – represented by a chromatic hierarchy of numeric values – was overlaid on maps containing the locations of the city’s cycling infrastructure, of the recorded cyclist routes, and of the sites in which traffic collisions involving cyclists had occurred. Results showed a large number of traffic collisions involving cyclists in highly accessible streets and a strong demand for a cyclist-oriented urban infrastructure, such as cycling paths and bike parking, among other facilities, as reported by cyclists. Space syntax analysis showed a direct association between cycling safety (or lack of it) and accessibility: street segments that are highly chosen with reference to certain radii (between 3 and 5km in the case of Natal) concentrate most routes and collision sites. However, the location of cycling infrastructure items do not coincide with these places of high risk as this infrastructure is concentrated in some high-income areas, which although encompassing a highly accessible street network, leaves out some of the busiest and most chosen thoroughfares – the ones mostly used to move through the city. Besides that, some of the cycling routes are shared with other transport modes, such as buses and cars, apparently to avoid taking space away from automobiles. In short, the placement of cycling infrastructure in the studied city has not been oriented by what is the actual purpose of that infrastructure – to mitigate the traffic unsafety experienced by cyclists – because it is concentrated not in the riskiest streets, but in high-income, low-density areas, often in streets with low through-movement potential, thus contributing towards urban inequality and as a factor of land speculation.