1. Technical Committee on Geometric Design
AASHTO
Technical Committee on Geometric Design

2. AASHTO Standing Committee on Highways
AASHTO Subcommittee on Design
AASHTO Technical Committee on Geometric Design
Provide a focal point and working group for developing and recommending AASHTO geometric design criteria. This assignment includes formulating new and revised criteria to keep current all geometric design standards, polices, and guidelines.

3. AASHTO Technical Committee on Geometric Design
States from each of the four regions
FHWA; serves as secretary
American Public Works Association
League of Cities
National Association of County Engineers

4. Publication Responsibilities
A Policy on Accommodation of Utilities within Freeway Right of Way, 2005
A Policy on Design Standards – Interstate System, 2005
Guide for Accommodating Utilities within Highway Right of Way, 2005
Guide for Development of Rest Areas on Major Arterials and Freeways, 2001

5. Publication Responsibilities
Guide for the Planning, Design, and Operation of Pedestrian Facilities, 2004
Guidelines for Geometric Design of Very Low Volume Local Roads (ADT < 400), 2001
Guide for the Development of Bicycle Facilities, 1999 (NCHRP 20-7 Project Coordinated with Technical Committee on Non-motorized Transportation)

6. Research Proposals and Oversight
Design Speed Alternatives for Selecting Geometric Criteria
One – and Multi-Lane Loop Ramp Design
Designing Roadway Transitions from Rural Highways to Urban/Suburban Highways or Streets

7. Research Proposals and Oversight
Updated Headlamp Design Criteria for SAG Vertical Curves
Superelevation Criteria for Sharp Horizontal Curves on Steep Grades
Accommodating Oversize/Overweight Vehicles at Roundabouts

8. A Policy on Geometric Design of Highways and Streets
( Green Book )

9. Chapter 1
Highway Functions

10. Chapter 1 Highway Functions

11. Chapter 1 Highway Functions

12. Chapter 1 Highway Functions

13. Chapter 1 Highway Functions

14. Proposed Changes
Designer Consideration of the Context of the Project Area
Highlights the Flexibility Available to Encourage Choosing Design Criteria:
Consistent with the Context of the Project
Needs and Value of the Community
With Respect to Economic Limitations
Chapter 1

15. Design Controls and Criteria
Chapter 2
Design Controls and Criteria

16. Design Control & Criteria
Chapter 2
Design Control & Criteria

17. Design Control & Criteria
Chapter 2
Design Control & Criteria

18. Proposed Changes Adding SU-40 Single Unit Truck (3-axle)
Removing WB-50 Semitrailer Truck and Replacing with WB-62
Adding WB-92B – Rocky Mountain Double
Chapter 2

19. Chapter 3
Elements of Design

20. Chapter 3
Elements of Design

21. Chapter 3
Elements of Design

22. Proposed Changes
Stopping Sight Distance Tables Clarified Whether on Level, Wet Weather, or Grades
Passing Sight Distance for Two-Lane Highways Revised (NCHRP Report 605)
Height of Object will Include Discussion About Decision Sight Distance
Chapter 3

23. Proposed Changes continued
Revision Method for “Lane Drop Taper Length” for Passing Lane Sections
Lighting – Updated to Conform to the Roadway Lighting Guide
Chapter 3

24. Cross Section Elements
Chapter 4
Cross Section Elements

25. Proposed Changes
Traveled Way Definition Revised to be Consistent with Roadside Design Guide
Rumble Strip Section Added Based on State Experience and TRB/FHWA Research
Chapter 4

26. Proposed Changes continued
Roadside Design Discussion Provided in a More Consistent Format with the Roadside Design Guide
Sidewalks and Curb Ramps – Updating Discussion to Conform to AASHTO Pedestrian Guide and ADAAG
Chapter 4

27. Local Roads and Streets
Chapter 5
Local Roads and Streets

28. Local Roads and Streets
Chapter 5
Local Roads and Streets

29. Local Roads and Streets
Chapter 5
Local Roads and Streets

30. Proposed Changes
Updated Reference to AASHTO LRFD Bridge Design Specifications
Reorganized Clear Zone Discussion
to Roadside Design
Added Discussion of Level of Service in Rural/Urban
Chapter Reorganized to Generally Follow Other Functional Chapters
Chapter 5

31. Collector Roads and Streets
Chapter 6
Collector Roads and Streets

32. Collector Roads and Streets
Chapter 6
Collector Roads and Streets

33. Collector Roads and Streets
Chapter 6
Collector Roads and Streets

34. Proposed Changes
Chapter Reformatted to Provide Some Consistency with other Functional Classification Chapters
Adding Text About Selection of LOS for this Functional Classification
Roadside Design Discussion
Chapter 6

35. Arterials (Rural & Urban)
Chapter 7
Arterials
(Rural & Urban)

36. Arterials (Rural & Urban)
Chapter 7
Arterials (Rural & Urban)

37. Proposed Changes
Added Discussion About Characteristics of Urban Arterials
Added Discussion About LOS Selection for Urban Arterials
Revised Discussion About the Relationship Between Design Speed and Lane Width
Chapter 7

38. Proposed Changes Continued
Benefits of Medians to Pedestrians in Urban Areas
Added Discussion About Off-Setting Left Turn Lanes When Selecting Median Widths
Chapter 7

39. Chapter 8
Freeways

40. Chapter 8
Freeways

41. Proposed Changes
Added Discussion on Superelevation Rates on Freeways Considering Snow/Ice, Viaducts, and Section Consistency
Reformat to Generally Sequence Other Functional Classification Chapters
Reorganize Clear Zone Discussion to Roadside Design
Chapter 8

42. Chapter 9
Intersections

43. Chapter 9
Intersections

44. Proposed Changes
Chapter Being Reformatted to Provide Better Sequence of Design Material
Adding Discussion of Intersection Capacity Based on HCM
Updating Discussion of Roundabouts and Adding Discussion of Continuous Flow Intersections
Chapter 9

45. Proposed Changes continued
Expanding the Discussion of Indirect Left Turns and U-turns
Based on TRB Access Management Manual:
Definition of Functional Area
Components of Auxiliary Lanes
Deceleration Length Discussion
Adding Design Criteria for Double/Triple Let Turns – NCHRP 505
Chapter 9

46. Grade Separations and Interchanges
Chapter 10
Grade Separations and Interchanges

47. Grade Separations & Interchanges
Chapter 10
Grade Separations & Interchanges

48. Proposed Changes
Updating Exhibits for Directional/Semi-directional Interchanges
Including an Exhibit for Diamond Interchange with Roundabout Intersection Control
Providing Discussion of Two-lane Loop Ramp Design
Providing Additional Guidance on Ramp Metering
Chapter 10

49. Green Book Schedule
Currently doing a technical mark up for consistency
Committee meeting in the Fall of 2009
One more technical review
Ballot in the First Quarter of Calendar 2010

50. Technical Committee on Geometric Design
AASHTO
Technical Committee on Geometric Design