A STUDY ON A STREET LIGHTING THAT MAKES CHANGE ILLUMINANCE IS EFFECTIVE FOR BOTH REDUCING FEAR OF CRIME AND SAVING ENERGY

摘要

Recently crime number increases in urban area, so environmental design for crime prevention is needed. Additionally, fear of crimes is increasing in our daily life in immediate surroundings. For this reason, relieving residents' fear of crimes is important as well as prevention of crimes. We have developed an street lighting fixture capable of detecting people and changing its illuminance. The dimmer ratio is 0.3. Because at dimmer ratios ranging from 0.28 to 0.44, at least 90% of subjects can notice the changes in illuminance well and do not be discomfortable. And I examined in the actual installation site to validate its effects of giving a sense of security to residents, preventing crimes, and saving power. The questionnaires show that in a percentage of 82% evaluate that change illuminance with motion sensor gives them more sense of security. Nobody responds that changes in illuminance are uncomfortable, with 63% of the responses "not discomfortable", and 37% of the responses "favorable". The comparison of electrical energy between actual measurement at site and measurement during fully lighting shows 34% of energy saving. I clarified that the new street lighting fixture is effective for both reducing fear of crime am saving energy. In addition, this is effective about improvement light pollution. I expect that this lighting fixture is spread in many outdoor fields.