How to distinguish the entrance and exit of expressway tunnel

Expressway is a high-grade highway, fully enclosed, and the traffic speed is the highest highway grade in China. In road signs, expressways are the same as national highways, starting with the letter "G", such as G65 Expressway.

The letters of provincial expressways begin with "S", such as S9 Expressway. National highways and provincial highways are in white font with green background, with red stripes above the national highways and yellow stripes above the provincial highways. It should be noted that the expressways starting with the letters "G" and "S" are all closed expressways, but the sign starting with "S" means that this section belongs to a certain province and there is no other meaning.

Above the motorway, there will be lane information tips every once in a while, including speed limit tips, lane names or restricted vehicles will be displayed above. What you need to pay attention to is that the speed limit information of each lane is different. If you drive in the lane with a speed limit of 100/ km, you will also be caught violating the rules.

Extended data:

1, according to the geological conditions of the tunnel: soil tunnel and rock tunnel.

2. According to the tunnel length: short tunnel (railway tunnel: L ≤ 500m; Provisions for highway tunnels: l ≤ 500m), medium and long tunnels (provisions for railway tunnels: 500m)

3. According to ITA's definition of tunnel cross-sectional area, there are very small cross-section tunnel (2 ~ 3m2), small cross-section tunnel (3 ~ 10m2), medium cross-section tunnel (10 ~ 50m2) and large cross-section tunnel (50 ~ 100m2).

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