What is the standard width of a slow lane?

[CameronLynn]

The standard width for a slow lane is 2×7.5 meters for a four-lane bidirectional road; 2×11.25 meters for a six-lane bidirectional road; and 2×15 meters for an eight-lane bidirectional road. The national standard for the width of each motor vehicle lane on highways is as follows: For multi-lane highways above Level III, the width of each motor vehicle lane is 3.5-3.75 meters. There is no uniform standard for the central divider, which is adapted to local conditions. A simple cement central divider is one meter wide, while for a central green divider, there is no uniform standard. Some 'image project' roads can have dividers as wide as several dozen meters. Classification of urban roads: Urban roads are categorized into three levels: expressways, arterial roads, and secondary roads, with the following red line width controls: expressways should be no less than 40 meters, arterial roads 30-40 meters, secondary roads 20-24 meters, and branch roads 14-18 meters.