2004 Green Book

1

• 2004 Green Book
• Changes include
• Superelevation
• M Middle ordinate of horizontal curve
• Technical Corrections

Green Book Interstate Standards constitute
basic design standards for NHS adopted by FHWA
2

• Superelevation revisions include
• Reworded and rearranged topics
• Friction factors revised from three separate
  curves to one curve, minor changes to values for
  low speed
• Reformatted superelevation tables, minor changes
  to values for low speed design
• Length of superelevation runoff moved to separate
  table
• New table for low speed urban streets
  (superelevation optional)

3
Friction factors for superelevation
Design 2001 2004 Speed Green
Book Green Book
15 0.175 0.32 20 0.170
0.27 25 0.165 0.23 30 0.160
0.20 35 0.155 0.18 40 0.150
0.16 45 0.145 0.15 gt 50
Same
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2004 Green Book
2001 Green Book
5
Superelevation table from 2001 Green Book
Exhibit 3-23. Values for Design Elements Related
to Design Speed and Horizontal Curvature (emax
8)
6
Superelevation table from 2004 Green Book
Exhibit 3-27. Minimum Radii for Design
Superelevation Rates, Design Speeds, and emax
8
7
Middle Ordinate of Horizontal Curve -- 2001
Exhibit 3-58. Diagram Illustrating Components
for Determining Horizontal
Sight Distance.
8
Middle Ordinate of Horizontal Curve -- 2004
HSO Horizontal Sightline Offset
Exhibit 3-54. Diagram Illustrating Components
for Determining Horizontal
Sight Distance.
9
Technical Corrections

• Page 145, Replaced 8 values in Exhibit 3-14
  (Minimum radii for horizontal curves)
• Page 589, Replaced 6 values in Exhibit 9-19
  (Design for turns at intersections)
• Page 838, Replaced Exhibit 10-60 (Typical gore
  details for exit terminals)
• Page 843, Replaced column heading in Exhibit
  10-67 (Design widths for turning roadways)
• Corrected typos
• Corrected incorrect exhibit references

Errata listings for previous editions
http//downloads.transportation.org/Errata-GDHS-4.
pdf
10
States are therefore allowed to use either the
2001 or 2004 Green Book as the design standard
for projects on the NHS.
11

• Replaces 1991 Policy
• FHWA will formally adopt through Federal Register
  process
• Added metric values
• Design speed for rolling terrain eliminated, now
  same as level terrain
• Revised shoulder width discussion for mountainous
  terrain
• Sloping curbs, when allowed outside shoulder,
  limited to 4-inch height

A Policy on Design Standards Interstate System