78|A FONDO Parque Renato Poblete, Santiago, Chile. Luz en espacios públicos sin encandilamiento. LD: DIAV a stronger feeling of unsafety due to a sense of vulnerability to crime but also because poor visibility in a roadway can cause accidents such as falls and crashes. However, the answer is not an excess of light and glare; it would be like solving hunger with obesity. The mere presence of light is no guarantee of safety in public spaces. Concerning safety, lighting design should be considered with regard of the furniture, landscaping, pavement, usage and the respective luminar-ies (levels of light on the surfaces) as well as glare control. Safety in connection with crime prevention and vandalism is a highly debated topic. It hasn’t been proven by studies that lighting and/or an increase in levels of light, in and of itself, lowers crime. In other words, it’s a fact that there is some consensus that good lighting increases “the feeling” of safety, but it does not reflect in figures of crime reduction, which at the end is what matters to the community. Even though I can’t offer stud-ies done in Ibero America, associating and comparing figures of crime with changes in the levels and design of lighting in different public spaces, we can take as reference the conclusions reached in various studies in North America and the United Kingdom (IESNA-G-1-03). Lighting can affect crime indirectly through two mechanisms: 1.-Supports the surveillance of the authorities and/or the community after dark. Only if the criminal perceives the increase in surveillance or concern with the public space as an increase in the effort and risk involved versus the benefit obtained, will the levels of crime be reduced. However, when the increase in surveillance is not associated to some punishment linked to the crime, lighting will not help. Brief calculation of urban energy expense in 10x10 Km of city: Surface of 100.000.000 m2 Conservative estimates, state that 20% of that surface is illuminated public space (circulation areas for pedestrians and vehicles, squares, parks, etc.). In total, there are 20.000.000 m2. If some regulations are demanding between 10lux to 20 lux for public spaces such as circulation areas for pedestrians and vehicles, a standard distribution, with very efficient Led luminaries that would achieve those levels, is approximately 2 Watts/m2, which means that 20.000.000 m2 consuming 2W/ m2, will have an expenditure per hour of 40.000.000 Watts. If we multiply this by the cost per watt/hour, we will arrive at the cost of illuminating a city all night. Ej: Chile, 0,1€ per KW/h, are 4000€/hour, in 12 hours it’s 56,000€. ¿Why does it have to be illuminated to a maximum, all night long? If we know that 2/3 of the night, the use of public spaces is down to a minimum, why not lower illumination to 3 lux and reduce usage to a 1/3, as a result. Planning illumination levels according to use can be done with timers or sensors.