Superelevation and Spiral Curves - PowerPoint by XheIWQY

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									Superelevation and Spiral
         Curves




                            1
Source: A Policy
on Geometric
Design of
Highways and
Streets (The Green
Book).
Washington, DC.
American
Association of
State Highway and
Transportation
            2
Officials, 2001 4th
Ed.
Source: A Policy
on Geometric
Design of
Highways and
Streets (The Green
Book).
Washington, DC.
American
Association of
State Highway and
Transportation
            3
Officials, 2001 4th
Ed.
4
Source: CalTrans Design Manual online,              5
http://www.dot.ca.gov/hq/oppd/hdm/pdf/chp0200.pdf
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
                                       6
                           Officials, 2001 4th
                           Ed.
                                            Same as point E of GB
  With Spirals




                                                                    7
Source: Iowa DOT Standard Road Plans RP-2
          With Spirals




 Tangent runout (A to B)



                                            8
Source: Iowa DOT Standard Road Plans RP-2
          With Spirals




          Removal of crown



                                            9
Source: Iowa DOT Standard Road Plans RP-2
          With Spirals




                               Transition of
                               superelevation
                                                Fully superelevated


                                                                  10
Source: Iowa DOT Standard Road Plans RP-2
  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 Transportation11
                                                             Officials, 2001 4th Ed.

								
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