What is the difference between an expressway and an elevated road?

[VictoriaFitz]

The differences between an expressway and an elevated road are as follows: 1. Speed limits vary: Expressways generally have a speed limit of 80, while highways typically have speed limits of 100-120. 2. Toll charges differ: Highways require toll payment for passage, whereas expressways are toll-free. 3. Control measures differ: Expressways should have a central divider between opposing lanes, with full or partial control at entry and exit points. Highways are dedicated roads for high-speed, lane-separated vehicle travel with full access control. 4. Design specifications differ: Highways require smooth alignment, minimal gradient, 4-6 lane widths, central dividers, high-performance asphalt or concrete pavement, and sturdy guardrails where necessary - features not required on expressways. 5. Coverage areas differ: Expressways serve as high-grade roads within cities or between cities and satellite towns with limited coverage. Highways connect cities over larger distances with broader coverage.

[DiAlaina]

I have to study my commuting route every day, as expressways and elevated roads are fundamentally two different design concepts. Expressways are mostly built in suburban or urban fringe areas, like Shanghai's Outer Ring Road or Beijing's Fifth Ring Road, with no traffic lights throughout and connected in all directions via interchanges, specifically designed for fast intercity travel. Elevated roads, on the other hand, are typical urban solutions built directly above existing roads, such as Chengdu's Second Ring Elevated Road, specifically targeting ground-level traffic congestion. The spacing of on- and off-ramps on elevated roads is particularly critical—missing an exit within a kilometer means a long detour. Moreover, during construction, elevated roads have a greater impact on ground traffic, requiring phased enclosures and often involving the demolition of old bridges to build new ones.

[WyattDella]

I've been in transportation for over a decade, and these two drive completely differently. Elevated roads usually have an 80 km/h speed limit, but ramp entrances often drop to 40 km/h with many sharp turns that easily cause tail swings. Expressways allow speeds up to 100 km/h with fewer curves and wider lanes, making them particularly stable for heavy trucks. The road signs also differ significantly - elevated roads use blue signs with white arrows for clear markings, while expressways have green backgrounds with white characters indicating longer distances. Most crucially, elevated roads have dense exits - miss one and you can immediately take an overpass to circle back; but on expressways, missing an exit means driving several kilometers forward to make a U-turn, wasting considerable time.

[Doreen]

I am a bridge engineer, and structurally speaking, the differences are enormous. The full name of an elevated road is 'elevated bridge,' which uses concrete box girders or steel box girders suspended in the air, standing 6-8 meters above the ground entirely supported by columns. The piers of Nanjing's Yingtian Avenue Elevated Road alone have a diameter of 1.5 meters, with entire rows of piers resembling a giant matrix. Most expressways are built on roadbeds and pavements, excavated 6 meters deep and layered with three levels of stone materials for compaction. During heavy rain, drainage relies entirely on underground pipe networks. Special sections, like Hangzhou's Qiantang River Expressway, use continuous rigid frame bridges with spans of 200 meters, requiring no piers and relying solely on their own strength to span the river surface.

[MariaLynn]

I live above a market in the old city area, watching the elevated highway traffic every day. The elevated highway built in the downtown area is extremely noisy; even with sound barriers installed, I can still clearly hear the gear shifts of trucks at midnight. Opening the window for just half an hour leaves a layer of dust on the windowsill, and on rainy days, mud splashed up by wheels reaches the fourth-floor balcony. Expressways, at least 500 meters away from residential areas, are much quieter. However, the space under elevated highways has been creatively utilized—for instance, the space under Suzhou's East Ring Elevated Highway has been converted into badminton courts, and the piers of Chongqing's Huanghuayuan Bridge are covered in graffiti, making them far more interesting than the monotonous slope protection walls along expressways.