What is the width of a bidirectional six-lane road?
3 Answers
The width of a bidirectional six-lane road is 3.75 meters, with a mandatory separation zone or green belt in the middle. When necessary, an extra-wide non-motorized vehicle lane of over 3.5 meters and a sidewalk of over 4 meters must be established. For a bidirectional six-lane expressway, the design speed is 80-120 km/h, with a subgrade width of over 33 meters. Each lane is 3.75 meters wide, requiring the installation of green belts, shoulders, emergency lanes, and emergency parking strips ranging from 1.5 to 3.5 meters. A separation zone is set up in the middle of the road, using high-grade pavement materials such as asphalt concrete or cement concrete. The road is equipped with complete signage, markings, signals, and lighting installations. Pedestrians and non-motorized vehicles are prohibited from walking on the road, with intersections designed as overpasses, pedestrian bridges, or underpasses. Highway construction is a linear project, and the social, economic, and natural environments along the route can vary significantly. The terrain, features, and traffic volume may not be identical and can even differ greatly. Therefore, for a relatively long highway, different numbers of lanes or different highway grades can be adopted in sections based on changes in the surrounding conditions and traffic volume.
As someone with some traffic design experience, I believe the width of a bidirectional six-lane road typically ranges between 25 to 30 meters, averaging around 28 meters. Each standard lane is approximately 3.5 meters wide, so the base width for six lanes is 21 meters. However, in reality, you need to add a central median, which is about 2 to 4 meters wide, to prevent collisions from oncoming traffic; plus shoulders or safety zones on both sides, each 0.5 to 1 meter wide. Adding these up naturally brings the total width to the mentioned range. The advantage of wider lanes while driving is easier overtaking and higher safety, especially in congested urban areas, where it helps reduce accidents. I've also noticed that newly constructed highways tend to be wider, as their design accounts for future traffic growth. Overall, wider roads are better for sections with high traffic volume and busy conditions.
I've been driving for over a decade, and a six-lane bidirectional highway feels particularly smooth to drive on, with an estimated width of around 30 meters. Each lane is typically about 3.5 meters wide, making three lanes in each direction totaling six, with a median strip or green belt in the middle. The actual width depends on road conditions; for urban main roads like Beijing's ring roads, the width ranges between 28 to 32 meters, which prevents congestion even with heavy traffic. I frequently go on long trips, and wider lanes provide much more driving comfort, significantly reducing the chance of side-swipes. Additionally, the extra width allows for buffer space, making driving in rain or snow more stable. Expanding on related points, narrow road designs are prone to traffic jams, so I recommend choosing these wider roads for travel, as they save time and enhance safety.
