The report Stockholm city’s regional biking plan presents information of a continuously rising numbers ofcyclists in central Stockholm. However, the central parts of Stockholm have not now, or in the near future,the capacity or structure to provide a functional as well as safe traffic situation, especially for cyclists. Theincreasing demand from traffic of the commuter street network in central Stockholm make the 6 km longunderground maintenance tunnel along the newly build Citybanan commuter train tracks a possible andinteresting alternative for safe, fast and easy bicycle travelling underneath Stockholm. The tunnel stretchesfrom Fatbursparken to Tomteboda, with exits/entrances along the route in central parts of Stockholm[Fig 1.]There are several examples in the world where former car, train and maintenance tunnels are used as bikingtunnels. The longest existing example is the Croix Rousse tunnel in Lyon, France (2013). A 1,3 km longtunnel with separate lanes for cyclists, pedestrians and commuter busses, which also functions as anevacuation tunnel to the parallel car tunnel. Another example is the Lugaritz-Morland bicycle tunnel in thecity of San Sebastian, Spain (2009), which is a former railway tunnel (850 metres) that connects twoneighbourhoods in the city.The specific conditions a tunnel have with no daylight and limited access, give the lighting designer theimportant task to shape the space using light.Light is the factor that makes us see the world, our visual ability is depending on the light. Light has theability to reveal and transform the character of a space and influence how the observer experiences thesituation, both physically (by vision) and psychologically (emotional experiences as comfort and feeling ofsafety). Therefore a good visual condition in public space, traffic as well as enclosed spaces like tunnels, arevery important and a basic need for humans in the city.The aim with this thesis was to develop a lighting strategy and proposal for the maintenance tunnel ofCitybanan in Stockholm, based on literature and case studies research, a full-scale light observation by areference group in a tunnel context as well as research by questionnaires. The primary purpose of the fullscalelight study was to confirm literature research hypotheses about the importance of light distributionand experienced spatial atmosphere in relation to psychological effects, as well as the importance of lightgiving information. Findings confirm and shows that light distribution have a great impact on how theobservers experience the space visually, as well as emotionally. Findings also show that light can influencepeople’s behaviour to intuitively slow down or be alert. Further this thesis results show that giving a spaceit’s own identity by collaboration between light, colour and architectural elements have a great impact onthe psychological experiences of a space regarding safety, comfort and social interaction, crucial factors in atunnel environment for cyclists.The thesis results in a concept presented in the Proposal chapter, based on design principles and a lightingstrategy where a combination of light typologies is used to create a human centred and comfortableenvironment. Light is used as guiding element and for spatial understanding to create comfort and supportsocial interaction. In addition the concept includes a theme used as inspiration in the lighting strategy tocreate a connection on a human scale between the cyclist and the space. The theme is based on a commonpreference of the reference group, as well as my personal, for the ideal dream biking environment;In the nature. Experiencing for example the variation of light filtered through the leaves, the sunset and theabsence of traffic.The aim with the proposal is to transform the tunnel to an attractive bicycle route for daily cyclists inStockholm, as well as being an interesting tourist attraction.- A large underground landmark and art piece stretching under the city of Stockholm.

Para atenuar o impacto visual, que acomete o motorista ao ingressar em túneis rodoviários durante o período diurno, utiliza-se a luz artificial, com alto nível inicial e gradual diminuição para o interior do túnel. Tal solução apresenta dois inconvenientes imediatos, relacionados ao consumo de energia e à segurança. Devido à radiação solar direta, as imediações da entrada do túnel tornam-se fontes de ofuscamento de elevada intensidade e a iluminação deve estar dimensionada para permitir, ao motorista que se aproxima da entrada do túnel, a visualização de seu interior, implicando em elevado consumo de energia para uma tarefa com pouco requisito visual. Quanto à segurança, na hipótese de falta de energia aumenta-se a probabilidade de acidentes, pois o reflexo do motorista pode ser frear. As soluções arquitetônicas, objeto da pesquisa, correspondem a um Sistema para Adaptação Visual (SAV), implantado no trecho de rodovia aberta anterior à entrada do túnel, que, por um lado, atua nos elementos causadores do problema e, por outro, fornece a iluminação necessária no interior do túnel através das fontes de luz natural (Sol e céu). Para sua concepção, são propostas cinco estratégias. O desempenho do SAV, assim constituído, foi testado em uma aplicação prática nos túneis do trecho Oeste do Rodoanel Mário Covas, sem apresentar os inconvenientes identificados na solução convencional (iluminação artificial). A segurança no ponto crítico ficou garantida por característica intrínseca do sistema. Além de reduzir o consumo, a energia para o período noturno pôde ser gerada pelo próprio SAV, se incorporados módulos fotovoltaicos, e a sazonalidade característica da luz natural é acompanhada pelo sistema, favorecendo o conforto visual por diminuir a faixa em que ocorre o processo de adaptação visual. / The usual adopted solution to defuse the drivers visual impact at the highway tunnel entrance during the daytime, has been the use of electric lighting, with high initial level and gradual reduction towards the internal side of the tunnel. This brings two immediate problems, concerning energy consumption and security. Direct sunlight causes high intensity glare sources around the tunnel entrance, and the lighting level should be enough to allow the interior visibility, when the driver approaches the tunnel, entailing high energy consumption to a low accurate task. Security-wise, in case of power supply failure, collisions possibility increases, due to the drivers instinctive reaction to brake suddenly. Architectural solutions, this research object, are related to a Visual Adaptation System (VAS) positioned on the open road before the tunnel entrance, which, on the one hand, acts into the problem causes, and, on the other, provides the necessary lighting inside the tunnel by natural light sources (Sun and sky). Five strategies are proposed designing the VAS. A practical application on Metropolitan Area Ring Road Mario Covas West segment tunnels checked the so-built VAS performance, not presenting the identified deficiencies in the conventional solution (artificial lighting). The intrinsic system feature assured the critical point security. Besides the consumption reduction, the energy supply for nighttime could be generated by the VAS, if photovoltaic modules are added, and the natural light seasonal feature is followed by the system, favoring the visual comfort by decreasing the visual adaptation process range.

Para atenuar o impacto visual, que acomete o motorista ao ingressar em túneis rodoviários durante o período diurno, utiliza-se a luz artificial, com alto nível inicial e gradual diminuição para o interior do túnel. Tal solução apresenta dois inconvenientes imediatos, relacionados ao consumo de energia e à segurança. Devido à radiação solar direta, as imediações da entrada do túnel tornam-se fontes de ofuscamento de elevada intensidade e a iluminação deve estar dimensionada para permitir, ao motorista que se aproxima da entrada do túnel, a visualização de seu interior, implicando em elevado consumo de energia para uma tarefa com pouco requisito visual. Quanto à segurança, na hipótese de falta de energia aumenta-se a probabilidade de acidentes, pois o reflexo do motorista pode ser frear. As soluções arquitetônicas, objeto da pesquisa, correspondem a um Sistema para Adaptação Visual (SAV), implantado no trecho de rodovia aberta anterior à entrada do túnel, que, por um lado, atua nos elementos causadores do problema e, por outro, fornece a iluminação necessária no interior do túnel através das fontes de luz natural (Sol e céu). Para sua concepção, são propostas cinco estratégias. O desempenho do SAV, assim constituído, foi testado em uma aplicação prática nos túneis do trecho Oeste do Rodoanel Mário Covas, sem apresentar os inconvenientes identificados na solução convencional (iluminação artificial). A segurança no ponto crítico ficou garantida por característica intrínseca do sistema. Além de reduzir o consumo, a energia para o período noturno pôde ser gerada pelo próprio SAV, se incorporados módulos fotovoltaicos, e a sazonalidade característica da luz natural é acompanhada pelo sistema, favorecendo o conforto visual por diminuir a faixa em que ocorre o processo de adaptação visual. / The usual adopted solution to defuse the drivers visual impact at the highway tunnel entrance during the daytime, has been the use of electric lighting, with high initial level and gradual reduction towards the internal side of the tunnel. This brings two immediate problems, concerning energy consumption and security. Direct sunlight causes high intensity glare sources around the tunnel entrance, and the lighting level should be enough to allow the interior visibility, when the driver approaches the tunnel, entailing high energy consumption to a low accurate task. Security-wise, in case of power supply failure, collisions possibility increases, due to the drivers instinctive reaction to brake suddenly. Architectural solutions, this research object, are related to a Visual Adaptation System (VAS) positioned on the open road before the tunnel entrance, which, on the one hand, acts into the problem causes, and, on the other, provides the necessary lighting inside the tunnel by natural light sources (Sun and sky). Five strategies are proposed designing the VAS. A practical application on Metropolitan Area Ring Road Mario Covas West segment tunnels checked the so-built VAS performance, not presenting the identified deficiencies in the conventional solution (artificial lighting). The intrinsic system feature assured the critical point security. Besides the consumption reduction, the energy supply for nighttime could be generated by the VAS, if photovoltaic modules are added, and the natural light seasonal feature is followed by the system, favoring the visual comfort by decreasing the visual adaptation process range.