What Are the Differences Between Urban Roads and Highways?

[DeEverett]

Urban roads and highways have the following differences: 1. They belong to different administrative systems: urban roads fall under the transportation system, while highways are managed by the construction and housing system. 2. Their typical working environments differ: urban roads are usually located in mountainous or rural areas, whereas highways are commonly found in urban or market areas. Additional information on urban roads and highways is as follows: 1. Urban road density refers to the total length of roads per unit area within an administrative region. Medium-sized cities have a road density of 5.2-6.6 km, while large cities with populations over 2 million have a density of 5.4-7.1 km. 2. Expressways are designed to accommodate an annual average daily traffic (AADT) of over 25,000 vehicles. They hold significant political and economic importance, are exclusively for high-speed, continuous, and segregated vehicle traffic, feature full-grade interchanges and controlled access, and primarily serve long-distance transportation. 3. Class I highways can handle an AADT of 5,000-25,000 vehicles. They connect major political and economic centers, provide access to key industrial zones, allow for rapid segregated vehicle movement, and feature partial access control and grade-separated interchanges. 4. Class II highways can accommodate an AADT of 2,000-5,000 vehicles (converted to medium-duty trucks). They link political and economic hubs or large industrial zones and serve as heavily trafficked suburban roads. They typically have four lanes (two in each direction). 5. Class III highways can handle an AADT of fewer than 2,000 vehicles (converted to medium-duty trucks). They serve as general arterial roads connecting counties or linking counties to cities. These roads usually have two lanes, with a width of 8.5 meters in flat areas and 7.5 meters in hilly regions. 6. Class IV highways can accommodate an AADT of fewer than 200 vehicles (converted to medium-duty trucks). They function as feeder roads connecting counties to towns or villages. For example, the old Bingchacha Road in the new Yunnan-Tibet corridor is 3-4.5 meters wide, has a gravel base, and is considered a simple road.