JAUE2017-025: Field Measurement of Streetlight Illuminance in a Residential Area

Abstract

In this study, a questionnaire survey was carried and the streetlight illuminance at night was measured in a 
residential area in Iizuka City, to grasp the current condition, and to propose measures to ensure residents' living 
environment more securely. “Questionnaire survey on brightness at night” was administered to parents and 
guardians of all 123 students of Iizuka Elementary School. In addition, to investigate the field situation of the 
Tokuzen District, the illuminance directly under street light, the horizontal illuminance, and the vertical 
illuminance were measured on October 14, 2016 and November 17, 2016. After that, the uniformity ratio for each 
road section was calculated by the horizontal illuminance. The roads were classified into 4 levels, by using the 
illuminance standard at “3 Lux” in JIS Z 9111-1988 and the uniformity ratio standard at “0.2” in JIES-010/ (2014).
Of the roads in the district, 35.8% were satisfying average illuminance, and the remaining roads did not satisfy 
average illuminance. The results of carrying out field measurement showed that points not satisfying the 
illuminance standard accounted for more than 70% of points in the district. Locations in front of main streets and 
stores exhibited high values, and thus the average illuminance in Tokuzen, Iizuka City, satisfied the standard at 
3.48 Lux.