Improvement of visibility by dynamic control of expressway tunnel lighting and establishment of total revealing power

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K13959
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 25020:Safety engineering-related
• Research Institution: Ehime University
• Principal Investigator: Ikeda Yoshihisa 愛媛大学, 理工学研究科(工学系), 准教授 (00735318)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: トンネル照明 / LED / プロビーム / ダイナミック制御

Outline of Final Research Achievements

To improve visibility by dynamic control of expressway tunnel lighting and to establish dynamic total revealing power evaluation, a 1/24 scale expressway tunnel model for visibility evaluation was fabricated and visibility evaluation was conducted by subjects. Visibility evaluation was conducted using a 20 cm square indicator located 100 m away in the tunnel as a simulated fallen object. The most significant result of the multivariate analysis of visibility and various optical parameters was the combination of the luminance ratio between the luminance of the falling object and the luminance of the background road surface and the horizontal illuminance, and visibility was mostly determined by the luminance ratio. In addition, even when the luminance ratio was 1, visibility was possible when the chromaticity difference was larger than the McAdam ellipse (3-STEP).

Free Research Field

照明工学

Academic Significance and Societal Importance of the Research Achievements

トンネル照明を含む交通照明は従来のナトリウムランプや水銀ランプからLEDへの置き換えが進んでいるが、LEDの長所および短所の理解が進まない内に導入されてしまっている。特にトンネル照明では輝度の高いLEDの導入でグレアが目立ち、路面の視認性が著しく低下したトンネルも見受けられる。本研究成果は、トンネル照明をLEDにする場合に最も重要なトンネル内の視認性に寄与する光学パラメータを明らかにしており、学術的意義は高い。また将来トンネル照明設置ガイドラインが見直される場合に、重要な知見を提供することが可能であり、社会的意義としても高い成果を得ている。