隧道照明,出口段,入口段

2010 International Conference on Intelligent Computation Technology and Automation

Safety Analysis for Illumination Design at Tunnel Entrance and Exit

WANG Yan

Road Safety Research Center Research Institute of Highway,

Ministry of Transport Beijing, 100088, China whj98741@126.com

GUO Zhong-yin

School of Transportation Engineering, Tongji University Shanghai, 201804, China zhongyin@mail.tongji.edu.cn

II.

LIAO Zhi-gao

General Station of Quality Inspection for Special Engineering

of Civil Aviation Beijing, 100007, China lzgcaac@126.com

Abstract—The illumination design is an important factor affecting driving safety at tunnel entrance and exit. By analyzing lightness change character and visual adaptation mechanism at tunnel entrance and exit, the lightness transition index has been developed. Due to the shortage of accident statistics at tunnel entrance and exit, indirect analysis method was adopted and operating speed difference was selected as medium index to evaluate driving safety. Based on theoretical and statistical analysis, the relation between lightness transition index and operating speed difference at tunnel entrance and exit has been modeled. At last, the recommendation for designing safer lightness transition condition at tunnel entrance and exit has been discussed.

SAFETY PROBLEM AT TUNNEL ENTRANCE AND EXIT

A. Lightness change character at tunnel entrance and exit A number of investigations were carried out to study the lightness change character at tunnel entrance and exit. Influenced by the natural light, the lightness outside tunnel is much higher than that inside tunnel in the daytime. The lightness declines rapidly from tunnel entrance or exit to tunnel inside. The figure1 and figure 2 below display the lightness change character at tunnel entrance and exit. The lightness change character at tunnel entrance and exit can be described schematically, shown in figure3 and figure 4. (2) The lightness declines fast in the segment from entrance

Keywords - traffic safety; illumination design; tunnel

to point A and slowly in the segment from point A to point B. From point B to tunnel inside, the lightness tends to be stable. I. INTRODUCTION

The location of point A is about 25 meters far away from

Tunnel is a common construction in highway networks entrance. The location of point B is about 50 meters far away especially in mountainous area. Being the transitional section from entrance. The lightness change character at exit is connecting two different driving environments, tunnel similar to that at entrance. The location of point C is about 25 entrance and exit experienced higher traffic accident rate meters far away from exit. The location of point D is about 50 because the design of road and traffic facilities at this zone is meters far away from exit. not good enough for drivers to adapt the change of driving

3250environment. As is shown in the research works on road

safety in tunnels, the illumination design at tunnel entrance Shan Tunnel

Left Entranceand exit is critical for driving safety.(1) In order to improve 2750

Da Liang driving safety at tunnel entrance and exit, one of the most Shan Tunnel

important things is to improve illumination design to provide Right

Entrancebetter lightness transition condition. Yang Shan 2000In this paper, the lightness transition index has been Tunnel Left

Entranceestablished by analyzing the lightness transition character and

Yang Shan the visual adaptation mechanism of drivers at tunnel entrance Tunnel Right

and exit. The operating speed difference was selected as the Entrance1250medium index to relate lightness transition character to He Cheng 1000

Tunnel Right driving safety. By adopting regression analysis to the

Entrance

investigated data on operating speed and lightness at tunnel

500entrance and exit, the relation between the lightness transition

250index and the operating speed difference at tunnel entrance

and exit has been modeled. On this basis, the safety assessment criterion for illumination design at tunnel entrance -40-20020406080100120and exit has been provided. At last, the recommendation for Distance to Tunnel Entrance(m)

designing safer lightness transition condition at tunnel

entrance and exit has been discussed. Figure 1. Lightness change curve at tunnel entrance

Lightness(cd/m2)