A Light Booster metro car for the commuting work force : Human Centric Lighting in underground transportation

Abstract: People at northern latitudes lack an effective portion of daylight, especially in winter time, to entrain their circadian rhythm. If one belongs to the group of employees who have no time for daylight exposure and are not supplied by Human Centric Lighting (HCL) in their office, the only chance to get circadian light may be the daily commute. The mega trend of urbanisation increases time of commute, with on average 20-60 minutes spent daily in public transportation in European cities. By introducing HCL to public transport, especially metro vehicles, this time frame can be used to provide the commuting work force with circadian lighting. A LIGHT BOOSTER metro car is proposed to provide the right intensity, spectral distribution, directionality and timing of light to regulate the human inner clock and support health. The LIGHT BOOSTER metro car is very efficient as light is best used due to a high person per square meter ratio. This ratio is higher than in any office building. The energy consumption equals that of an conventional single household. Besides expected health benefits, the LIGHT BOOSTER metro car works as an educative tool, raising awareness for the beneficial effects of light on human health and well-being.