What does two-way four-lane mean?

[Dante]

Introduction to two-way four-lane roads: 1. Two-way four-lane highway: The design speed is 60-80km/h, and the subgrade width is 24.5 meters. For national highways, provincial highways, first-class highways, and second-class highways, each lane is 3.75 meters wide. When necessary, a non-motor vehicle lane of more than 3.5 meters and a sidewalk of more than 4 meters must be established (except for second-class highways). 2. Two-way four-lane expressway: The design speed is 80-120km/h, the subgrade width is 26 meters, and each lane is 3.75 meters wide. Green belts, shoulders, emergency lanes, and emergency parking strips of 1.5-3.5 meters must be established.