In civil engineering, a reverse curve (or "S" curve) is a section of the horizontal alignment of a highway or rail route in which a curve to the left or right is followed immediately by a curve in the opposite direction.[1][2]
On highways in the United States 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.[3]
On rail routes, reverse curves can cause buffer-locking. On the Northeast Corridor in the United States, these also hinder the development of high-speed rail.[4]
- ^ Mundrey (2000). Railway Track Engineering. McGraw-Hill Education. pp. 164–179. ISBN 9780074637241.
- ^ Harry Rubey (1956). Route Surveys and Construction. Macmillan Publishers. pp. 86–88.
- ^ Federal Highway Administration (1971). Manual on uniform traffic control devices for streets and highways. U.S. Government Printing Office. p. 67.
- ^ "Analysis: Long road ahead for improving Northeast Corridor speeds".