Author(s)

RICHARD A. MORRISON

Abstract

Urban Transport Design must cater for an ever-increasing population of vehicles in the modern world. Increasingly more complex interchanges are created to enable the flow of mankind in, through and under cities. These complex structures include normal roads, motorways, underpasses and tunnels. As these necessary interchanges increase in size and scale, so too does the need for lighting. The resulting sky glow is evidence of wasted energy. The amount and type of lighting is dictated by the requirements of standardised codes of practice, designed to ensure safety and reduce risk to the authorities in charge, and the drivers themselves. Within these standards can be found guides for the application of daylight which are often overlooked. Reducing the need for lighting assists in reducing sky glow, and the consumption of energy and resources. In this paper, 4D modelling of daylight (3D + time) is used to reduce the requirement for lighting in an Urban Transport Tunnel by over 40%. The full extent of available daylight across a calendar year under worst case and best case scenarios is modelled to ensure that all seasonal effects are considered. Utilising the lowest mean average of available light on the carriageway indicates the minimum reduction available to the designer. More complex modelling then allows to further dim the lighting system. This paper demonstrates the techniques used in 4D daylight modelling and proves that the methodology can be used to reduce consumption of lighting energy, installation infrastructure and cost. Additional case histories demonstrate that the savings are available in any geometry or location.

Keywords

tunnel lighting, transport lighting design, 4D modelling, daylight analysis, daylight harvesting