But the high speed in which the street lights are installed is only a small part.
Highways don't need street lights
The reason why the highway does not install street lights is because it is not particularly necessary for street lights.
High-speed no pedestrians, non-motor vehicles, no street lights
The main function of street lamps is not only for road lighting, but for the convenience of pedestrians and protection of non-motor vehicles.
The highway is completely closed, no one, no electric car, plus the road is relatively flat, there are no traffic lights, sharp turns, these things, the demand for street lights is actually not big.
When driving at high speed, the headlights have met the lighting requirements.
On the other hand, the car itself has headlights. When the high speed is turned on, the headlights are turned on, basically satisfying all the needs.
Not only is the road clear, the roadside signs look very bright, there are reflective films on the top, the theoretical reflectivity reaches 100%.
Xinhuanet has a report, "The Reflective Principle of Reflective Markers on Highways", its reflection distance can reach 1000m.
When the driver is at a distance of 400m, it can distinguish colors, figures and symbols. When the distance is 200m, the above words are completely ok.
Except for street signs, is there a marking on the road? It is also reflective.
The Ministry of Communications has published standards, "Pavement Marking Paint": In the hot-melt anti-cursor line coating, 18% to 25% of glass beads must be mixed.
Using the thin lens imaging principle, the light emitted by the light source can be retroreflected to the light source.
When the headlights are on, the road markings, road signs and reflections are particularly obvious. You don't have to rely on street lights to illuminate it.
There is still a light in the bridge, tunnel, etc.
Of course, the highway is not full of street lights.
Some special road sections, such as bridge decks and tunnels, still have to be equipped with lights. Because the country has requirements, it must be installed.
"Code for Design of Road Tunnels" and "Code for Design of Road Lighting", two documents: In tunnels with a length greater than 100m, lighting should be set.
In addition, there are multiple motorway bridges, 2 lanes and 3 lanes, which cannot be used as lighting functions.
To be honest, it is necessary to have a "high pole" to pick up, and the streetlights from the top down can be. Not only do you have to install it, but you also have regulations.
Highways with street lights may not be safe
In addition to the above, the second reason why highways are not equipped with street lights is that street lights have a negative impact on high-speed security "may".
The Philips China Research Institute has an experiment in which the driver's maximum eye position illumination is provided by light at a 70° angle from his nearest street light.
Light above this angle will be cut off by the roof, and the illuminance of the eye near this angle will drop drastically.
Periodic eye illuminance oscillates "huh huh huh huh", which can cause driver discomfort.
Needless to remember, to say that people are, when we drive, part of the roof is blocked, the light and dark are constantly alternating, bright and dark, bright and dark.
It`s as if someone took a flashlight and swayed back and forth in front of you. When the eyes were shaking for a long time, people would be stupid, and it would affect their judgment.
If the national high-speed street lights are installed, the cost is too high.
No street lights, the most important thing is not to afford
The two reasons just mentioned, how do you mean "the bones in the egg". In fact, the main reason for not installing street lights on highways is that they cannot afford them.
Just like, why not buy Rolls Royce? There are many reasons: the fuel consumption is too high, the performance is generally the same, not environmentally friendly, the car is too big, it is inconvenient to open, parking is quite troublesome.
The main reason is that I can't afford it.
There are indeed some places in the world where high speed is fully covered: Belgium, Emirate of Abu Dhabi, United Arab Emirates.
They all have two common characteristics: the first feature is called rich; the second feature is called land area is relatively small.
Belgium is a veteran capitalist developed country with high taxes. The land area is only a little over 30,000 square kilometers, almost as large as two Beijing.
And Abu Dhabi has 92% of the oil reserves in the UAE. It`s really called [rich oil" and it`s a trivial matter.
The speed of a small part of the street lamp is because it is enough to make money
For our country, the cost of installing a streetlight for the entire highway is too high.
I said at the beginning: China's total speed of 143,000 kilometers, the world's first, and Belgium is less than 2,000 kilometers, we are not a fraction.
Therefore, there are only a small number of high-speed vehicles in China that can make their own money, and they have the qualifications for installing street lamps, such as: Guangzhou-Shenzhen Expressway.
This high-speed highway is called "the busiest high-speed in the country", with a total length of 122.8 kilometers. In 2018, the average daily traffic volume is 1 day, 594,200. There is no off-season throughout the year and there are cars available 24 hours a day.
CCTV's "First Time" program group has an investigation. Guangshen Express has invested in 15 years and its income has exceeded 30 billion. The cost of building and operating street lights is of course a small case.
Expensive is the main reason for not installing street lights
In general, the main reason why the domestic high-speed does not install street lights is expensive.
For some roads with large traffic volume, they can be profitable and can be loaded.
For the roads with small traffic, relying on the lighting of the lights, isn`t it also good? So it will not be installed.
Why domestic high speed, the maximum speed limit is only 120
Speaking of this today, it is a small talk of making friends, you can talk. Regarding high speed, "cold knowledge" is still very much.
For example, we all know that the domestic high-speed speed limit, the highest is 120, in fact, is the standard set by nearly 40 years ago, how was it decided in the past year?
Why is it not 110, or 130, or 140?
In the past, many high-speed, older friends know that they are all cement. How can they be replaced with asphalt now? But after switching to asphalt, why is the cement inside the toll station still cement?
Keywords: high speed
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