In
civil engineering
Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewa ...
, a reverse curve (or "S" curve) is a section of the horizontal alignment of a highway or railroad route in which a curve to the left or right is followed immediately by a curve in the opposite direction.
On highways in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
reverse curves are often announced by the posting of a W1-4L sign (left-right reverse curve) or a W1-4R sign (right-left reverse curve), as called for in the
Manual on Uniform Traffic Control Devices.
Reverse curves on the
Northeast Corridor
The Northeast Corridor (NEC) is an electrified railroad line in the Northeast megalopolis of the United States. Owned primarily by Amtrak, it runs from Boston through Providence, New Haven, Stamford, New York City, Philadelphia, Wilmington, ...
in the
USA hinder the development of
high-speed rail.
Reverse curves cause
buffer-locking.
See also
*
S bridge
*
Road curve
Road curves are irregular bends in roads to bring a graduation change of direction. Similar curves are on railways and canals.
Curves provided in the horizontal plane are known as horizontal curves and are generally circular or parabolic. Curves ...
*
Track geometry
Track geometry is concerned with the properties and relations of points, lines, curves, and surfaces in the three-dimensional positioning of railroad track. The term is also applied to measurements used in design, construction and maintenance of t ...
References
Railway track layouts
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