ccnovels Chapter 389 Urban Road Network Design?
Chapter 389 Urban Road Network Design?
"I'm designing the city." An Yulong said in a dabbling voice.
Song He was startled and suddenly understood!
The dozens of paper balls that I had just seen were immediately spread out in front of my eyes. The various formulas and calculations were all clearly connected in series, and the numbers seemed to come alive!
"Kinks represent abstracted ramps, intersections and viaducts?" Song He said, "The transmission efficiency of different paths represents the traffic speed of vehicles?"
An Yulong nodded, "The project I am working on is to try to design the most efficient urban road network and establish a road mathematical model!"
"In the future, urban expansion and road renovation in various cities can be integrated into this mathematical model to verify whether the road design is reasonable!"
"Sounds like a lot of merit!" Song He was very interested and put on a flattering smile, "Can I learn from you? I learn new things very quickly. Once I learn it, I can help you do some small jobs with scraps!"
"I don't have time to teach you." An Yulong looked cold.
Song He was slightly embarrassed and quickly thought about how to convince him. This homeless man had a very withdrawn personality and never had a smile on his face.
"There are still four hours for this flight. If you can complete the basic test within four hours, I can consider it." An Yulong thought for a moment and suddenly changed his mind, "Bring me the mobile phone!"
Song He quickly took out his mobile phone, stood up and held it with both hands.
An Yulong clicked twice on his phone, touched Song He's phone lightly, and threw it back.
Song He quickly grabbed his phone, and a new file suddenly appeared!
"Thank you, teacher!"
He turned to thank him, but An Yulong didn't seem to hear him. He lowered his head and kept writing on the white paper with a pencil, immersed in the paper.
Song He frowned slightly, he had a feeling that he hadn't caught An Yulong's eyes yet!
The so-called four-hour test is just to stop yourself from asking questions, just like a parent throwing out a small toy to avoid the entanglement of a naughty child.
That's all, let's try the toy first to see how difficult it is. If it's very easy, we can quickly solve it and continue to stalk An Yulong!
Song He clicked on the file on his phone and browsed with his head down.
His face became surprised!
I thought it was nothing more than designing a few ramps and elevated roads, no matter how difficult it was, but unexpectedly the real situation was much more complicated!
[The design of a road network mathematical model cannot exist in isolation from the external environment, and various variables must be considered]
[1. Based on the distance that can be reached within half an hour on foot, by bicycle, or by car, three-level blocks are set up respectively. The road network should consider the convenience and interrelationship of the three-level blocks]
[2. The total urban population, the total population in third-level neighborhoods, and the number of migrant populations in tourist cities are all important factors in road network design]
[3. The functional division of different blocks, such as residential areas, commercial areas, industrial areas, and tourist areas. Different functional blocks have different flow of people and different means of transportation]
【4. The traffic volume at different times should be fully considered. Can the road carry the morning and evening peak hours? Is there smooth traffic around places with dense traffic such as hospitals, schools, large factories, etc.? 】
[5. Cities are not static, and road construction should leave room for subsequent development in different urban areas]
…
One condition after another, there are more than 30 items listed in detail!
Song He was shocked. The workload of this mathematical model was really huge beyond imagination!
In general, the core idea is to ensure that the vast majority of people in the city have convenient transportation, imagine themselves as a resident of the city, and fully consider various situations.
At the end of the file, there is a test question!
A simulation map of an old small town with a population of 150,000. It is necessary to find the congestion locations and improve the roads appropriately!
The current comprehensive congestion rate in old small urban areas is: 58%!
Song He was hard to stretch, and there was a traffic jam for more than half of the time. The road condition was rated as: history.
"Teacher, can I borrow a few pieces of paper?" Song He turned to ask.
An Yulong continued to write and draw without raising his head.
Song He hit a wall and was about to bend down to pick up the paper ball on the ground to look for any blank paper. An Yulong suddenly ripped off a layer of the white paper and threw it over.
"Thank you, teacher!" Song He quickly caught it.
Take out a gel pen from your pocket and get to work!
The principle of mathematical models is very simple. It expresses the actual situation in mathematical language and then condenses the rules.
Song He had read a lot of An Yulong's drafts before, and probably knew his habits, so he wrote the formulas according to the gourd's drawings.
With just a few strokes, the situation of a small block was calculated!
Starting well, Song He expanded methodically, expanding the calculation range clockwise, deriving block after block on paper.
This feels like an expedition general leading a formula army, attacking cities and territories all the way!
But soon, the situation on paper became complicated at a speed visible to the naked eye!
When there are only one or two intersections, the traffic flow can be seen at a glance.
But when it reaches ten intersections, the traffic flows at different intersections begin to affect each other, just like a continuous grid in a chess game. Each step must consider the situation of adjacent grids, and the amount of calculation increases dramatically!
The number of intersections increased to fifty, and Song He was dazzled!
He imagined the city as a whole in his mind. The blocks were like lotus leaves. Dozens of lotus leaves were closely connected to form a small lotus pond called the city.
Under normal circumstances, when a gentle breeze blows and dozens of lotus leaves sway slightly, conventional calculations can barely handle it.
The bell rang suddenly, school on a lotus leaf was over!
In a primary school with 5,000 people, parents come from all over to pick up their children!
Like a fat toad suddenly jumping onto a lotus leaf, a lotus leaf swayed violently from side to side, and the surrounding lotus leaves also collided and shook collectively. The tremors were transmitted layer by layer and weakened layer by layer, and the huge lotus pond was shaking non-stop!
Song He was sweating on his forehead.
He had to introduce more advanced calculations and add a layer of equations to deal with sudden traffic peaks under the original conventional mathematical modeling to prevent events like "school out" from ruining the entire mathematical modeling.
Continue to expand, one hundred intersections!
The previous fifty intersections were still inside the city, and were square streets with horizontal and vertical lines.
It has expanded to a hundred intersections and has reached the edge of the city. Many roads have become irregular, with crooked roads, diagonal roads, dead ends, and bridges across rivers emerging one after another!
Moreover, the scale is so large that there will be more chain reactions. If a street is blocked due to a traffic accident, several surrounding streets will also be blocked. Once there are schools, hospitals and other places nearby, the congestion will expand violently and spread to most of the city. !
The situation was almost like a butterfly effect. A car broke down at the intersection, causing traffic jams throughout the city, and the GDP and happiness index plummeted!
Song He was sweating profusely. The previous mathematical modeling was completely useless and he almost had to start over again!
"Whoa!" He tore off a piece of papyrus paper, balled it up and threw it on the ground.
After a moment, it was "Shua!"
"Whoosh!" "Whoosh!" "Whoosh!"
Song He kept tearing off pieces of scratch paper, and he was sweating all over!
He touched his phone and looked at the time. He was shocked. Two hours had passed before he knew it!
Half of the exam time has passed, but the mathematical modeling in my hand has not even finished the foundation!
Is this wave really going to overturn?
Is An Yulong right to be contemptuous? Are you really incapable of solving this kind of math problem?