街路空間における防犯性・安全性を高めるための照明環境に関する研究

Description

Abstract (English)

This study aims to clarify appropriate lighting environments for enhancing crime prevention and safety in street spaces, based on human behavior, psychological responses, and spatial characteristics. Conventional street-lighting design has generally emphasized compliance with quantitative standards, such as horizontal and vertical illuminance. However, a sense of security and ease of walking in actual street environments cannot be achieved simply by increasing the brightness of road surfaces. These qualities are also closely related to the visibility of surrounding buildings, open spaces, building openings, intersections, and other spatial elements.

First, this dissertation examines the lighting conditions required for safe walking on level roads, bridges, steps, and the common areas of residential buildings. It then focuses on “urban voids,” such as open spaces adjacent to streets, and analyzes their relationship with anxiety and spatial perception during nighttime walking. The analysis is based on field surveys, experiments involving the switching on and off of existing lighting, physical scale-model experiments, and simulations.

The study also investigates how light associated with buildings, particularly light emitted from windows, entrances, and other openings, affects pedestrians’ sense of security and their perception of the brightness of the streetscape. In addition, intersections where pedestrians, bicycles, and vehicles interact are examined to determine how lighting can help people recognize side streets and intersections in advance and anticipate potential hazards.

Based on these investigations and experiments, this dissertation proposes a lighting-planning approach in which light is appropriately distributed according to human activities and the specific characteristics of each location, rather than illuminating the entire street uniformly at high levels. The study considers crime prevention, safety, streetscape quality, and energy efficiency in an integrated manner and seeks to contribute to nighttime lighting environments that are compatible with the distinctive lifestyles and characteristics of local communities.