How wide is the subgrade of a bidirectional eight-lane road?
2 Answers
Bidirectional eight-lane road subgrade is 2x15 wide. Components of a highway: The highway surface mainly includes several major parts such as the main road, ramps, and auxiliary lanes. The main road is the carriageway, which is divided from left to right into overtaking lanes, fast lanes, and slow lanes (travel lanes) according to different quantities. Ramps come in complex and diverse forms, including functional ramps, acceleration lanes, deceleration lanes, collector-distributor lanes, and turning ramps, depending on their specific functions. Types of highways: Depending on the scale of the road, highways are divided into three types: bidirectional four-lane, bidirectional six-lane, and bidirectional eight-lane.
I've been driving for over a decade. The typical width of a bidirectional eight-lane roadbed ranges from 35 to 40 meters. Each lane is approximately 3.5 meters wide, totaling 28 meters for all eight lanes. The central divider is about 2 meters wide, serving to prevent head-on collisions. The shoulders on each side measure 2 to 3 meters, potentially bringing the total width to over 35 meters. Urban expressways are designed more compactly, around 30 meters wide, while highways are wider, reaching up to 40 meters. Driving on such roads feels quite spacious, reducing the risk of traffic jams and making driving more relaxed. The wider road provides better visibility and more space to handle emergencies. Overall, the roadbed width is determined by traffic volume, significantly reducing congestion during peak hours.
