What is the general width of a road?
4 Answers
Urban roads are classified into three levels: expressways, arterial roads, secondary roads, and branch roads. The width control for each level is as follows: expressways should be no less than 40 meters, arterial roads 30-40 meters, secondary roads 20-24 meters, and branch roads 14-18 meters. In urban planning, road width refers to the width of the carriageway and sidewalks only, excluding the width of urban greenery along the street outside the sidewalks. It is primarily determined by traffic volume and does not include the width of curbs. In addition, the design of each type of road also considers speed limits. The design speeds for various roads are as follows: Expressways in urban areas are equipped with a central divider, have four or more lanes, and are fully or partially grade-separated with controlled access, allowing cars to travel at higher speeds. Also known as motor vehicle-only roads, the design speed for expressways is 60-80 km/h. Arterial roads connect different districts of a city and primarily serve traffic functions. The design speed for arterial roads is 40-80 km/h. Secondary roads serve as distributors between arterial roads and various districts, also providing service functions. The design speed for secondary roads is 40-60 km/h. Branch roads connect secondary roads to neighborhood roads (residential area roads) and mainly serve service functions. The design speed for branch roads is 30 km/h.
When I first learned to drive, I paid special attention to the width of the road because beginners often worry about scraping the car while parking or turning. Generally, the main roads in cities have four lanes in both directions, with each lane being about 3 to 4 meters wide. Including sidewalks and emergency parking lanes, the total width is about 15 to 20 meters. Alleyways are much narrower, only about 5 meters wide, some even less. Rural roads are usually 10 to 12 meters wide, while highways are even wider, with lanes and shoulders totaling over 30 meters. The width isn’t fixed—it depends on the road’s location and traffic volume. If it’s too narrow, accidents like collisions or traffic jams are more likely; if it’s too wide, it wastes resources. So, safety factors are considered during design to ensure good visibility for drivers. I always feel more relaxed driving on wider roads, while narrow roads require extra caution.
Having driven for over a decade, I've noticed significant variations in road widths, which differ from urban to rural areas. In city streets, a single lane is typically over 3 meters wide, with two-way roads including green belts spanning about 15 to 20 meters. Highway lanes follow a standard width of 3.5 meters, with total widths exceeding 30 meters, including emergency zones. Rural or mountainous roads are narrower, ranging from 5 to 10 meters, with some curved sections affecting visibility and overtaking. The differences in width primarily depend on traffic volume and terrain, while vehicle type also plays a role—large trucks require wider lanes, and narrow roads pose higher risks during rain or snow. I believe reasonable widths enhance driving safety and reduce congestion, as wider roads make long-distance driving much more comfortable, in my experience. Design also ties into regulations, such as minimum width standards in certain countries.
As someone who enjoys studying urban planning, I find road width quite fascinating. Typically, urban arterial roads are 15 to 20 meters wide, including lanes and sidewalks; highways can exceed 30 meters; while residential roads are narrower, around 5 to 8 meters. Width design considers traffic flow and safety—too narrow roads increase accident risks, such as vehicle scrapes or difficulty in reversing, and also limit turning radius. Many factors influence this, like population density and vehicle types—the SUV era requires slightly wider roads to accommodate. I often notice these details and find significant international variations, with European old-town roads as narrow as 5 meters and American suburban roads as wide as 25 meters. Standard lane widths range from 3 to 4 meters, and reasonable layouts can optimize traffic flow.
