What do the numbers of national highway and expressway mean respectively?

National highways and expressways all start with G, but the numbers behind them are different. National highways are numbered with three digits, and expressways are numbered with one, two or four digits.

China's road network extends in all directions. In order to better distinguish roads, we have given different names to different types of roads. Among them, national highways and expressways all start with G, followed by numbers. In addition, there are provincial roads, which start with S, and county roads, which start with X. Although both national roads and expressways start with G, the numbers behind them are different and have different meanings.

Generally speaking, there are three digits after the G of the national highway, and the first digit represents the road type. 1 This number represents the national roads that spread radially around the capital with Beijing as the center. Like a spider's web, there are 12 such national roads, with the numbers from g101~ g112. The number two indicates that all the national roads are north-south, that is, on the map of our country, they extend from the head of the chicken to the foot of the chicken. There are 27 such national highways, numbered from G20 1 to G228, of which G226 has been cancelled. Say one and two, and then talk about the national road starting with the number three. This part of the figure represents the east-west national highway. There are 29 national highways numbered from G30 1 to G330. The national road starting with the number three has been cancelled. On the map board of our country, it extends from chicken breast to chicken ass. ?

For expressways, the numbers after G can usually be divided into one, two and four. There is only one number, which represents the expressway from Beijing. The number behind the expressway has different meanings from the national highway. There is only one number at the back, which means the radial expressway from Beijing. And there are two digits after G, indicating the east-west or north-south high speed. If there are four digits behind, it generally represents the expressway around the city in a certain area or city. Generally speaking, the first two are bigger and the last two are smaller.

In short, if you just want to distinguish between national highways and expressways, then just look at the numbers after G, except for the three-digit national highways, all others are expressways, which is an obvious way to judge. If we want to carefully distinguish the types of national highways and expressways, we need to pay attention to some other factors. ?