Road width Why is the width of two lines on the highway three meters

This is a standard design value, generally 3.03.53.75m
Three meters should be a road below grade two
Mainly according to the car's width and safety distance to determine

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1. Design and build a road, the cross section of the subgrade is trapezoidal ABCD, as shown in the figure (unit: m). Set the height of the subgrade as h, and the slope angles on both sides as α and β, known as H = 2, α = 45 °, Tan β = 12, CD = 10. (1) calculate the width of AB at the base of the road; (2) how much earthwork is required to build such a subgrade 1000 m?
2. The design speed of two-way 8-lane expressway is 120km / h, and the general value of subgrade width is 45.00m. Who knows how to get the value?
3. The total mileage of expressways in a province is 1400km. If the subgrade width is 50m, how many square meters is the area of expressways in this province? How many square kilometers?
4. It took six days to build a highway, which was 140 meters above the midpoint. The rest continued to be built at the original speed, and it took another five days to complete. How long is the road?
5. Build a road. After five days, it is more than 160 meters above the midpoint. The rest will continue to be built at the original speed. It can be completed in four days. How long is the road?
6. After six days of building a highway, it is more than 150 meters above the midpoint. The rest will be built at the original speed. How many meters can the highway be completed in five days
7. After eight days of building a highway, it is more than 120 meters above the midpoint. The rest will continue to be built at the original speed and can be completed in six days. How long is the highway?
8. Workers build a road, 10 days later more than 30 meters, the rest of the original speed to continue to build, 9 days can be completed, how long is the road Write the meaning of each equation
9. It took 50 seconds for a train to pass through a 1140 meter long bridge (from the front of the train to the rear of the train leaving the bridge), and 80 seconds for the train to pass through a 1980 meter long tunnel?
10. There is a road beside the railway parallel to the railway. A 160 meter long train runs eastward at the speed of 54 kilometers per hour. At 7:10 a.m., it meets a worker walking westward and leaves the worker 10 seconds later. At 7:20 a.m., it meets a motorcycle running westward. After 5 seconds, it leaves the motorcycle and asks when it will catch up with the worker?
11. How wide is the effective width of the road
12. How to calculate the width of urban roads and highways? I often see that * * road is 80 meters wide and 8 lanes in two directions, or * * road is 12 meters wide and 4 lanes in two directions. I don't understand it. The first road with 80 meters wide can't get 80 meters when I look left and right, and the visual inspection is 30-40 meters at most (although it's not accurate, but it's not much different. For example, the 50 meter long runway and the 80 meter wide road obviously show that the runway is longer at a glance). Another example is the 8.5 meter wide road, where three people hold hands and are wider than the road, Three people add up to no more than six meters Please give an example. It's better to have a schematic diagram,
13. Road width standard It is said that science Avenue in Zhengzhou high tech Zone will continue to be built to the West. The new road is said to be 120 meters wide. Does this meet the national standard? The standards and guidelines (97 Edition) states that: Expressway road width (m) 60-100 Expressway road width (m) 60-80 Main road width (m) 40-60 Width of secondary trunk road (m) 30-40 From: Shenzhen Planning Bureau
14. In cross section design of urban road, assuming that the width of subgrade is 43M, how to arrange cross section
15. The width of the left subgrade, the width of the right subgrade, the filling area and the excavation area in the subgrade cross section are indicated by letters!
16. Please tell me how to draw the slope, the first figure
17. How to calculate the slope of 1:1.2 or 1:1.5
18. What is the drainage slope ratio of municipal roads? What are the longitudinal and transverse slopes? How to calculate?
19. I need to know the meaning and difference of road slope and longitudinal slope and how to calculate them
20. How to calculate and set out the road slope It is known that the elevation of point a is 0.200, the elevation of point B is 0.000, the distance between two points is 21m, and the slope is 1%. How to use the level to measure the slope and set out