Author: ccyou I live in Seattle, USA. It takes about 45 minutes a day for work and commuting (this is the case when the situation is good; sometimes it takes 2 hours for a one-way trip). This gave me a lot of time to observe the interesting modes of going to and from vehicles. Boring makes me illusionary of traffic, and a car is a huge water molecule. Many months passed and I gradually realized that it was not an illusion. Why do I never notice the "traffic fluid dynamics" that are clearly there? Just like this, I started to "spy" the traffic with my car - observation will eventually lead to trials, right? As an "amateur traffic dynamics", there are many things that can be done. However, first look at some basic phenomena. Have you ever encountered such a situation, you drove your car on the state highway, suddenly the road blocked, you moved forward inch by inch, waiting to see what happened in front of you It's these guys who cause traffic jams. But in a few moments, the vehicles in front of you are moving forward. The car is not blocked, there is no accident, no police car, nothing. What happened? Why didn't you get stuck in traffic? Looking from the rearview mirror, the unlucky drivers behind you are still trapped there. What caused this mysterious congestion? After many such invisible accidents, I came to the following conclusions. For ease of understanding, imagine that you are overlooking the entire traffic on a helicopter. Figure 1: After the accident, the vehicles are lined up behind. In (Fig. 1), I drew a one-way street, an accident, and a long chain of vehicles stuck behind the vehicle. The other cars stopped from the left and waited. Assuming that the car in the accident (indicated in red) is only temporarily parked there, it may just make a drop on the ice. What happens when the red car drives away? Figure 2: The traffic gradually "gathers" behind In the above (Figure 2A), obstacles were removed. But not all cars can go forward because most cars are trapped behind the stopped car. (Fig. 2B) shows the road conditions after a while, (Fig. 2C) is a further one. Notice the orange car (Fig. 2A) and see how it becomes unblocked in the plane and then begin to move forward. At the same time, the red car (Fig. 2A) approaches and is swamped in the blocked traffic. After the accident vehicle was removed, there seems to be no reason to continue the traffic jam. However, traffic jams will continue. The reason is simple: If I park behind a parked car, then I can't move forward and wait for the car behind me. All blocked cars are such a situation. Even if the obstacles causing traffic jams are gone, everyone is still in a state of rest, because if you want to drive, you have to start all vehicles together at the same time. The driver will not do this because each of them is waiting for the car in front to start. If I were stuck in traffic, even if I wanted to move forward, there would not be enough space. I would bump into the car in front of me. Other people's ideas are the same as me, so no one will move. When the car in front of me drove away, I still couldn't accelerate instantly, so I would stop for a moment. I must set aside some free time. If I suddenly accelerate, I will be too close to the car in front, and it will be very unsafe. Each vehicle will wait for a while to start again, which makes "traffic jam" start from the end of the accident site, gradually spread to the downstream, until disappeared. From the beginning (Fig. 2A), the vehicles were successively freed from congestion. (Figure 2B), the congested waves have been removed from the scene of the accident and have been far away in (Figure 2C) and (Figure 2D). But what is interesting is that although the car is moving from left to right, the motion direction of “evaporation wave†is opposite. It moves from right to left (※ has been corrected here) gradually into the traffic stream. Another point is very important. Although some cars are still parked, there are more cars jammed behind one another. Is the removal of the wreckage of accident vehicles, or will there be more and more cars "gathered" behind the traffic. The blocked traffic is like a solid, the front end is constantly evaporating and the back end is constantly crystallizing. The car is opened from left to right, but observe the whole of the stationary vehicle: the static movement slowly moves upwards, opposite to the direction of the car movement. The accident did not end, but it left a stream of congested traffic. This is not a traffic jam, but a shock wave that spreads through "car carriers." It is a traffic thrombus in the blood vessels, and traffic jams are constantly on the move. The crowded waves of these movements are common during traffic peaks. It doesn't have to be an accident to happen. Sometimes it's only a small amount of friction - supercars, driving lanes in the construction site, or just driving in a car from the ramp - all of this can be a wave. In the jargon of traffic engineering, these can all lead to "events" on the highway. You slow down the speed to watch the excitement and you may create such a wave. Every time you decelerate and merge roads to get off the highway from the next exit, you will also create such waves. Sometimes they appear out of nowhere. Such waves as the sea breeze blows, or ripples on the waving flags, are “emerging†from the traffic that passes through them. This is the so-called "self-discovery" in nonlinear dynamics. How long will the "crowded wave" last after the accident scene is cleared? Its life cycle depends on the amount of traffic and the number of vehicles trapped in congestion, but sometimes these things can last for many hours. When the flow of traffic is small, congestion may attenuate for a while. However, if the traffic volume is always high, then the congestion wave will not disappear at all. In addition, if the conditions are appropriate ("crystallization" is faster than "evaporation"), then even a small wave may increase. This is a bit like dropping a drop of seed into a bottle of supersaturated solution. When traffic is heavy and not stable, one driver may cause the entire traffic to freeze. So, the next time you get stuck in traffic, think of it as a pressure wave that hits your car and engulfs it. Think of traffic jams as a simple creature made up of cars rather than molecules. Don't be discouraged. Look forward to this crystal amoeba pulling your car out of it after a while. Wedge Wire Screen,Wedge Wire Filter,Wedge Wire Mesh,Wedge Screen ANPING HANKE FILTER TECHNOLOGY CO , https://www.anpinghankefilter.com
This is not a traffic jam. It is a shock wave transmitted through the car!