Transcript Superelevation and Spiral Curves

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