Expressway number is the number of expressway, and the grade and direction of expressway can be determined by expressway number. The national highway starts with G, and the number 1/2 represents the national highway. There are seven radial expressways from Beijing, numbered G 1-G7.

There are 9 expressways in the north-south direction, numbered with two odd numbers, with the range of G 1 1-G89. The east-west expressway 18 is numbered with two even numbers, and the range is G 10-G90. There are 4 regional high-speed loop lines numbered G9 1-G99.

Brief introduction of other situations of expressway.

Expressway is a kind of highway classified according to technical grade, which is higher than first-class highway, second-class highway, third-class highway, fourth-class highway and other highways. Expressway and national highway or provincial highway under the classification of road network state are cross-related, that is, expressway is a part of China Road or provincial highway of road network.