Highway tunnels have special structures. Compared with ordinary sections, traffic accidents, especially rear-end collision and wall collision, are frequent. It is of great significance to analyze the causes of tunnel traffic accidents and put forward the measures that can be taken to improve tunnel traffic safety.

1. The necessity of improving the safety of highway tunnels

(1) High incidence of tunnel traffic accidents such as rear-end collision and wall collision.

Statistical analysis shows that the main types of traffic accidents in the tunnel are rear-end collision, wall collision, rollover and fire, among which the number of rear-end collision and wall collision accidents is more.

Through the analysis of the cause of the accident, it is found that the sharp transition of the light environment at the entrance and exit of the tunnel and the dim, monotonous and closed driving and visual environment in the middle of the tunnel are the main causes of the accident. Basically, it is difficult to see the front car at the entrance of the tunnel, and it is also difficult to see the front car at the exit of the tunnel, which is what we often call the black hole and white hole effect. It is difficult to adapt to the vision, which brings serious optical illusion to the driver. At the same time, due to the reduction of the visual range, it is easy to cause rear-end collision and wall collision accidents.

(2) At present, the phenomenon of "high allocation and low utilization" in tunnels is common.

At present, there are nearly 20,000 highway tunnels in our country, and there is a widespread problem that tunnel electromechanical equipment can afford and can't afford it. According to statistics, the annual power consumption of highway tunnels in China is as high as tens of billions of kwh, and the cost exceeds tens of billions of yuan, so the power consumption is huge. However, in the case of huge power consumption, the turn-on rate of highway tunnels is far below the industry standard, and the phenomenon of "high allocation and low use" is remarkable. The light environment of highway tunnel is dim and monotonous, but this seemingly energy-saving way of not turning on the lights or turning on fewer lights sacrifices traffic safety.

Traffic accidents occur frequently in highway tunnels, and the present situation of tunnel environment is not optimistic. It is of great practical urgency to improve traffic safety and lighting energy saving in highway tunnels. It is the mainstream trend to improve the safety of highway tunnels at low cost. So, what are the specific measures to improve the safety of highway tunnels?

2. Measures to improve the safety of highway tunnels

(1) Shading shed at tunnel entrance

Shading shed can reduce the adaptive brightness near the tunnel entrance; To a certain extent, it reduces the power of intensive lighting, effectively reduces the energy consumption during tunnel operation, and has good energy-saving effect. The initial cost of shading facilities is high, but it can save a lot of lighting costs, which is beneficial in the long run and the landscape effect is also very good. Therefore, highway tunnels are rarely used, and urban tunnels are used more.

(2) Lighting of lamps and lanterns

▼ Backlighting

The projection mode of light is opposite to the driving direction, and most of the light is projected to the direction of the car, thus improving the background brightness of the target, making the vehicle or target in front easier to identify, and saving about 30% of lamps. Backlight lighting is easy to identify obstacles and improve the average brightness of the road surface, but the glare is obvious, so it is suitable for the tunnel entrance with small flow.

▼ Shunguang Lighting

Lighting lamps illuminate the road surface along the driving direction of the vehicle, and the angle between the illuminating light directly incident on the driver's eyes and the driver's line of sight is greater than the range angle caused by glare. Shunt lighting can improve the visibility of the vehicle in front and reduce glare, but the visibility is low, which is affected by the reflection of the tunnel wall and the road surface condition. It is suitable for urban tunnels with large flow and high speed.

(3) Sight-inducing facilities

▼ Delineator

Two-way delineator should be set on the side wall of the tunnel. When the tunnel is equipped with an access road higher than the road surface, delineator should be added at the top of the access road near the end of the roadway or the side wall of the access road; Delineator with high reflective performance and large reflector size should be set on the road sections with complex linear conditions.

▼ Tunnel contour belt

Tunnel contour belt, extra-long tunnel and long tunnel can be set up every 500m, and special sections such as poor sight distance should be properly encrypted; Tunnel contour belts may be set for unlit highway tunnels of Grade II and below.

END

To sum up several measures to improve the safety of highway tunnels, the shading facilities at the entrance and the lighting of lamps can improve the overall brightness of the tunnel, and the tunnel sight guidance facilities can improve the local brightness of the tunnel and increase the sight guidance of the tunnel. On the whole, sight guidance facilities are cost-effective and widely used, especially for low-grade highway tunnels with insufficient lighting and low maintenance.