Definition of primary and secondary roads

The first-class highway is a highway for cars to travel in different directions and lanes, and can generally adapt to the long-term design life of various cars converted into passenger cars, with an average annual day and night traffic volume of 1,500 30,000 vehicles. Secondary roads can generally adapt to the long-term design life of various vehicles converted into medium-sized trucks, with an average annual day and night traffic volume of 3,000,7,500 vehicles.

1. The service life is different.

The design service life of the primary highway is 20 years, and the design service life of the secondary highway is 15 years.

2. Adapt to the different traffic flow.

The primary highway refers to the annual average day and night passenger cars of 15,000 30,000 (four lanes) or 35,000-55,000 (six lanes) traffic, and the secondary highway meets the annual average day and night of 3,000 7,500 medium trucks.

3. The highway design is different.

The first-class highway is a highway for the town of sleepy cars to drive in different directions and lanes, and partially control access and three-dimensional crossing, mainly connecting important political and economic centers, leading to key industrial and mining areas, and is the trunk highway of the national royal finger. Secondary roads connect trunk roads in political and economic centers or large industrial and mining areas, or suburban roads with busy transportation.

Vehicle load: It is to take a large number of cars and cars arranged in the form of trains as the design load, and the occasional flatbed trailer or crawler as the check load. There are four classes of car train loads:

Automobile - Class 10, Automobile - Class 15, Automobile - Class 20, Automobile - Super Class 20. The load is divided into 800 kN, 1000 kN, 1200 kN flatbed trailer and 500 kN tracked vehicle. Impact forces, crowd loads, and other external forces that act infrequently on the bridge and culvert are not taken into account when the load calculation is used.

Highway level 1 refers to the design load level of the highway, the so-called load can be popularly understood as the weight of the car, our country divides the load grade of the highway into highway - grade and highway - grade, the highway - grade load is relatively large, suitable for the highway, a road grade is relatively high-grade highway, and the stuffy highway - grade is suitable for the lower grade of the highway.

Extended Split Stool Profile:

1. The difference between the load of highway level 1 and highway level 2 is that the load standard value used in the calculation schema is different, and the standard value of uniform load and concentrated load of highway level 2 lane load are used according to the multiple of highway level 1 lane load. The same standard vehicle load values are used for highway class 1 and highway class 2 vehicle loads.

2. Calculation of vehicle load.

There are many types of vehicles driving on bridges, including cars, flatbed trailers, tracked vehicles, road rollers, etc., and the opportunities for various types of vehicles on bridges are different. Frequently and massively appear as a vehicle load; Crawler trucks and flatbed trailers that appear occasionally and individually are used as tracked trucks and flatbed trailer loads. The calculation load is the vehicle load, and the check load is the crawler truck and flatbed trailer load.

(2) The first-class highway is a multi-lane highway for cars to drive in different directions and lanes, and can control access according to needs.

The four-lane first-class highway should be able to adapt to the annual average daily traffic volume of 15,000-30,000 cars converted into passenger cars;

The six-lane primary highway should be able to accommodate an average annual daily traffic volume of 25,000-55,000 converted from various vehicles into passenger cars

Vehicle. (3) The secondary highway is a two-lane highway for automobiles.

Two-lane secondary roads should be able to accommodate an average annual traffic volume of 5,000-15,000 vehicles per day converted into passenger cars.

Urban roads should be divided into fast according to the status of the road in the road network, the traffic function and the service function along the route.

There are four grades of roads, trunk roads, secondary trunk roads and branch roads, and shall meet the following requirements:

1. The expressway should be separated, all access control should be controlled, the spacing and form of entrances and exits should be controlled, and the traffic should be continuously passed, and the one-way setting should not be less than two lanes, and should be equipped with supporting traffic safety and management facilities.

There should be no entrances and exits for public buildings that attract a lot of traffic on both sides of the expressway.

2. Trunk roads should connect the main districts of the city and should be mainly used for traffic functions.

On both sides of the main road, it is not advisable to set up entrances and exits of public buildings that attract a large number of traffic flows.

The tertiary trunk road should be combined with the trunk road to form a trunk road network, which should be mainly used for the function of collecting and distributing traffic, and also have the function of service.

4 Branch roads should be connected with secondary roads and internal roads such as residential areas, industrial areas, and transportation facilities, and should be used to solve local problems.

Transportation, mainly service functions.

According to the "Technical Standards for Highway Engineering" (JTG B01-2003):

Secondary roads are two-lane roads for motorized vehicles. The two-lane secondary highway should be able to adapt to the annual average daily efficiency of 5,000 to 15,000 passenger cars.

Secondary highway design speed this 60 80km h. <>