Post on 18-Dec-2014
description
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Superelevation and Spiral Superelevation and Spiral CurvesCurves
Superelevation and Spiral Superelevation and Spiral CurvesCurves
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Source: A Policy on Geometric Design of Highways and Streets (The Green Book). Washington, DC. American Association of State Highway and Transportation Officials, 2001 4th Ed.
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Source: A Policy on Geometric Design of Highways and Streets (The Green Book). Washington, DC. American Association of State Highway and Transportation Officials, 2001 4th Ed.
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5Source: CalTrans Design Manual online, http://www.dot.ca.gov/hq/oppd/hdm/pdf/chp0200.pdf
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Maximum Relative Gradiant (G)
Source: A Policy on Geometric Design of Highways and Streets (The Green Book). Washington, DC. American Association of State Highway and Transportation Officials, 2001 4th Ed.
7Source: Iowa DOT Standard Road Plans RP-2
With SpiralsSame as point E of GB
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Source: Iowa DOT Standard Road Plans RP-2
With Spirals
Tangent runout (A to B)
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Source: Iowa DOT Standard Road Plans RP-2
With Spirals
Removal of crown
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Source: Iowa DOT Standard Road Plans RP-2
With Spirals
Transition of superelevation
Fully superelevated
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Length of Components (Cont.)
Length of Runoff: function of design speed, rate of attainment, and width of lanes – See Exhibit 3-29 p. 174 for two and four lane highways (based on appearance and comfort)
Source: A Policy on Geometric Design of Highways and Streets (The Green Book). Washington, DC. American Association of State Highway and Transportation Officials, 2001 4th Ed.