This arrangement of three boards and four belts has a large amount of greening and covers a large area. In summer, trees can form a dense arrangement, so it has a good shading effect.
Two isolation belts divide the roadway into three parts, with a motor vehicle lane in the middle and non-motor vehicle lanes on both sides. Coupled with street trees and four green belts on both sides, the contradiction of mixed traffic of vehicles is effectively solved, the interference between different vehicles is greatly reduced, and traffic is used, which is relatively safe.
But the land area is large and uneconomical. The section layout of three-board and four-belt roads has the disadvantages of large area and uneconomical. Three boards and four leading roads refer to the layout of road greening sections composed of three green belts, two motor vehicle lanes and two non-motor vehicle lanes.