Jeff Jones, P.E. Tennessee Department of TransportationJeff Jones, P.E. Tennessee Department of Transportation 1
Jeff Jones, P.E. Tennessee Department of Transportation
Topics to Cover
Ø AASHTO Technical Committee on Geometric Design
Ø Green Book, 7th Edition (GB7) Significant Changes
Ø Green Book, 8th Edition (GB8) Vision (time permitting)
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Jeff Jones, P.E. Tennessee Department of Transportation
Associate MembersNACE (National Association ofCounty Engineers)
National League of Cities
APWA ( American Public WorksAssociation)
Port Authority of NY, NJ
AASHTO Technical Committee onGeometric Design (TCGD)
(2)
Region 1
Region 2
Region 3
Region 4
Federal HighwayAdministration (Liaison)
AASHTO MembersRegion 1
Region 2
Region 3
Region 4
vacant
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Jeff Jones, P.E. Tennessee Department of Transportation
TCGD Publication Responsibility
1. Guidelines for Geometric Design of Low-Volume Roads, 2019
2. A Policy on Geometric Design of Highways and Streets (Green Book), 2018
3. A Policy on Design Standards - Interstate System, 2016
4. A Policy on the Accommodation of Utilities Within Freeway Right-of-Way, 2005
5. Guide for Accommodating Utilities Within Highway Right-of-Way, 2005
6. Guide for Development of Rest Areas on Major Arterials and Freeways, 2001
7. Guide for Protective Screening of Overpass Structures, 1990
8. Informational Guide on Fencing Controlled Access Highways, 1990
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Jeff Jones, P.E. Tennessee Department of Transportation
20182004
1984 1990 1994
20112001
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Jeff Jones, P.E. Tennessee Department of Transportation
Trivia Question
What Color(s) was the Green Book before it was Green ?
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Jeff Jones, P.E. Tennessee Department of Transportation
2011
1984 1990 19942001 2004 2018
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Jeff Jones, P.E. Tennessee Department of Transportation
Green Book, 7th Edition Update CycleJuly 2016 First Working Draft Complete Woods Hole, Ma
March 2017 Second Working Draft Complete Washington, DC
Summer 2017 Distributed for review to SCOD Members and allSCOD Technical Committees
Over 700 commentsreceived
Fall 2017 Ballot Passed TCGD
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Jeff Jones, P.E. Tennessee Department of Transportation
Green Book, 7th Edition Update CycleJuly 2016 First Working Draft Complete Woods Hole, Ma
March 2017 Second Working Draft Complete Washington, DC
Summer 2017 Distributed for review to SCOD Members and allSCOD Technical Committees
Over 700 commentsreceived
Fall 2017 Ballot Passed AASHTOTechnical Committee on Geometric Design
January 2018 Ballot Passed AASHTO Subcommittee on Design
March 28, 2018 Ballot passed AASHTO Council on Highways andStreets and AASHTO Board of Directors CHS: 38-2
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Jeff Jones, P.E. Tennessee Department of Transportation
Green Book, 7th Edition Update CycleJuly 2016 First Working Draft Complete Woods Hole, Ma
March 2017 Second Working Draft Complete Washington, DC
Summer 2017 Distributed for review to SCOD Members and allSCOD Technical Committees
Over 700 commentsreceived
Fall 2017 Ballot Passed TCGD
January 2018 Ballot Passed SCOD and Board of Directors
March 28, 2018 Ballot passed CHS CHS: 38-2
April 25, 2018 Files provided to AASHTO Publications
October 2018 Green Book Available for Purchase
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Jeff Jones, P.E. Tennessee Department of Transportation
General Changes
Ø Flipped the unitsØ Generally increased the design speed range
§ 80 mph – 85 mph
Ø Increased emphasis on multimodalØ New Context ClassificationsØ ADA / Section 504 requirements
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Jeff Jones, P.E. Tennessee Department of Transportation
Green Book, 7th Edition
• Foreword Preface• Chapter 1: Highway Functions• Chapter 2: Design Controls and Criteria• Chapter 3: Elements of Design• Chapter 4: Cross Section Elements• Chapter 5: Local Roads and Streets• Chapter 6: Collector Roads and Streets• Chapter 7: Arterials• Chapter 8: Freeways• Chapter 9: Intersections• Chapter 10: Grade Separations and Interchanges
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Jeff Jones, P.E. Tennessee Department of Transportation
Preface
• Rewritten... reorganizedØ Read
• GB4 - GB6: For Resurfacing (3R)Ø Use TRB Special Report 214
• GB7: For Resurfacing (3R)Ø Use NCHRP Report 876 Guidelines for Integrating Safety and
Cost- Effectiveness into Resurfacing, Restoration, and Rehabilitation(3R) Projects
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Jeff Jones, P.E. Tennessee Department of Transportation
• Preface• Chapter 1: Highway Functions “ New Framework for Geometric Design ”• Chapter 2: Design Controls and Criteria• Chapter 3: Elements of Design• Chapter 4: Cross Section Elements• Chapter 5: Local Roads and Streets• Chapter 6: Collector Roads and Streets• Chapter 7: Arterials• Chapter 8: Freeways• Chapter 9: Intersections• Chapter 10: Grade Separations and Interchanges
Green Book, 7th Edition
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 1 - New Framework for Geometric Design
Chapter Rewrite
NCHRP Report 855: An Expanded Functional ClassificationSystem for Highways and Street
NCHRP Report 785: Performance Based Analysis of GeometricDesign of Highways and Streets
NCHRP Report 839: A Performance-based Highway GeometricDesign Process
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Jeff Jones, P.E. Tennessee Department of Transportation
Based on NCHRP 855:
Going from 2 to 5 Context Classes
Two Rural (Rural and Rural Town)
Three Urban (Urban, Urban Core and Suburban)
Chapter 1 - New Framework for Geometric Design
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Jeff Jones, P.E. Tennessee Department of Transportation
GB7 Photos of “Rural” Context Classes
Rural Context Rural Town Context
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Jeff Jones, P.E. Tennessee Department of Transportation
GB7 Photo of “Suburban” Context Class
Suburban Context18
Jeff Jones, P.E. Tennessee Department of Transportation
GB7 Photos of “Urban” Context Classes
Urban Context Urban Core Context
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Jeff Jones, P.E. Tennessee Department of Transportation
ADA / Section 504 Guidance (28 CFR § 35.151)
New Construction:“The ADA requires that a public entity's newly constructed facilities mustbe made accessible to and usable by individuals with disabilities to theextent that it is not structurally impracticable to do so.”
Existing Facilities:“The ADA also requires that, when an existing facility is altered, thealtered facility must be made accessible to and usable by individuals withdisabilities to the maximum extent feasible.”
Chapter 1, Section 1.6.1 - “Pedestrians”
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Jeff Jones, P.E. Tennessee Department of Transportation
1.7 Design Process for Project Types
1.7.1 NEW CONSTRUCTION PROJECTSDesign guidance in Chapters 2 through 10 is primarily intended for new constructionprojects
1.7.2 RECONSTRUCTION PROJECTSDesign guidance in Chapters 2 through 10 is desirable, but may be impractical due toproject constraints and may not be relevant to project purpose and need
1.7.3 PROJECTS ON EXISTING ROADSProjects on existing roads are classified by the primary reason the project is beingundertaken (Project Purpose and Need)
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Jeff Jones, P.E. Tennessee Department of Transportation
Based on Project Purpose and Need
Purpose Potential Performance MeasureMobility / Speed (GB1+) v/c ratio, delay, LOSSafety Performance Crash rateSurface Condition IRI / RoughnessFreight Movement Travel Time ReliabilityBike, Ped and Transit LOS
Design of Projects on Existing Roads
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 2 - Design Controls and Criteria
Emphasizes transportation of/for people(as opposed to exclusively vehicles)ØMultimodal LOSØGreater emphasis on lower-speed, walkable, urban zones
Update to pedestrian walking speedØWas 2.5 – 6.0 ft/s (Now 3.0 – 3.5 ft/s)
Emphasizes the Highway Safety Manual andencourages its use
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 3 - Elements of Design
Added 85 mph [140 km/h] toSSD Table 3-1
Explanation of how to compute eand minimum R for design speedsgreater than 80 mph [130 km/h]
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 3 - Elements of Design
NCHRP Report 774 “Superelevation Criteria for Sharp Curves onSteep Grades”
•Potential operational issues with ‘e’ oversupply
•Added Equation 3-25 (pg 3-72) to check for that condition• (if criteria not met, reduce Se prior to PC or use spiral)
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 4 - Cross Section Elements
NCHRP Report 659(design of driveways)•Expanded discussion ofdriveway width guidelines
•Updated noise abatementdiscussion per latest FHWAdirection
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapters 5, 6 and 7
ØRevised urban street lane width discussion inChapters 5 & 6 to align with that in Chapter 7 – i.e.right sizing
ØRevised rural traveled way and shoulder widths tomore right-sized values§ Based on Highway Safety Manual data
ØAdded material presenting design speed ranges forspecific contexts
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapters 5, 6 and 7
Deleted section on bridges to remain in place(It’s no longer addressed in AASHTO bridge specifications)
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapters 6 and 7
Added a section based onNCHRP Report 737
(high to low speed transition zones)
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 7 - Arterial Roads and Streets
ØTitle changed from “Rural and Urban Arterials”◦Consistency with Chapters 5 and 6◦Reduces potential confusion created by new context categories
ØNew section and other new material on design inthe rural town context
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 7 - Arterial Roads and Streets
Urban Area Design
•Removed material on operational andcontrol measures
•Added a section on speed managementin design
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 8 - Freeways
ØRevised design speed guidanceto encourage right sized andcontext sensitive designs in urbanand suburban settings
(Away from “the higher the better” )
ØRemoved material targetingspecific levels of service
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 8 - Freeways
Technical CorrectionSection 8.2.4 “Traveled Way and Shoulders”
Added text regarding shoulders on freeways inMountainous terrain to be consistent with A Policyon Design Standards - Interstate System , AASHTO2016
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 9 - Intersections
New or revised drawings and/or text for…vChannelized right-turn lanesvOffset left-turn lanesvBypass lanesvReduced-conflict intersectionsØU-turn roadwaysØLoons
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Jeff Jones, P.E. Tennessee Department of Transportation
ØAdded discussion about ISD for roundabouts1. Reference to Sections 6.2.6 and 6.7.3.2 of NCHRP Report 672
(Roundabout Guide)2. Refer to GB7 Technical Corrections
regarding Roundabout figures
Ø Update Table 9-20 regardingfor deceleration turn lane length
1. Increased decel to 6.5 ft/sec2
Chapter 9 - Intersections
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Jeff Jones, P.E. Tennessee Department of Transportation
Chapter 10 - Grade Separations and Interchanges
Added Section 10.9.3.5“Diverging DiamondInterchanges (DDIs)”
AKA “Double Crossover Interchanges”
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Jeff Jones, P.E. Tennessee Department of Transportation
October 2019 Errata
The errata can be found on theAASHTO bookstore page
https://store.transportation.org
(then select the Green Book, 7th Edition)
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Jeff Jones, P.E. Tennessee Department of Transportation
GB8GB1
The AASHTO Green Book, 8th Edition (GB8)
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Jeff Jones, P.E. Tennessee Department of Transportation
Sep 28, 2017 NCHRP 20-7 (Task 423) (Phoenix)
Title: “Planning for a Comprehensive Update and Restructuring ofAASHTO’s A Policy on Geometric Design of Highways and Streets”
Contractor: Kittelson and Associates, Inc. , Portland, Oregon
Principal Investigator: Brian Ray
Schedule: May 2018 to May 2019
Objective: “…detailed roadmap to develop and implement the 8thEdition of the Green Book that supports a data driven, performance-based design process as described in NCHRP Report 839…”
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Jeff Jones, P.E. Tennessee Department of Transportation
Part IIntroduction
1 Overview2 Performance Based Evaluation Concepts3 Tort Liability and Risk Management
Part IIConducting Performance-Based
Evaluations
4 Performance Metrics5 Design Model6 Applying a Performance Based Process Framework
Part IIIRoadway Planning and Geometric
Design
7 Design Information and Sources
8 Roadway Design Fundamentals
Part IVFacility Types
9 Facility Type Considerations10 Local and Collector Roads11 Arterial Roads12 Freeways and Controlled Access Facilities13 At Grade Intersections14 Interchanges
Green Book 8th Edition Vision (NCHRP 20-7 Project)
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Jeff Jones, P.E. Tennessee Department of Transportation
1 Overview2 Performance Based Evaluation Concepts3 Tort Liability and Risk Management
Part IIConducting Performance-Based
Evaluations
4 Performance Metrics5 Design Model6 Applying a Performance Based Process Framework
Part IIIRoadway Planning and Geometric
Design
7 Design Information and Sources
8 Roadway Design Fundamentals
Part IVFacility Types
9 Facility Type Considerations10 Local and Collector Roads11 Arterial Roads12 Freeways and Controlled Access Facilities13 At Grade Intersections14 Interchanges
Green Book 8th Edition Vision(TCGD Meeting in Reno)
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Jeff Jones, P.E. Tennessee Department of Transportation
Part IIntroduction
1 Overview2 Performance Based Evaluation Concepts3 Tort Liability and Risk Management
Part IIConducting Performance-Based
Evaluations
4 Performance Metrics5 Design Model6 Applying a Performance Based Process Framework
Part IIIRoadway Planning and Geometric
Design
7 Design Information and Sources
8 Roadway Design Fundamentals
Part IV
Facility Types
9 Facility Type Considerations10 Local and Collector Roads11 Arterial Roads12 Freeways and Controlled Access Facilities13 At Grade Intersections14 Interchanges
Green Book 8th Edition Vision(TCGD Meeting in Reno)
Functional Class or Context Class ?
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Green Book 8th
Edition Vision(TCGD )
Part Ch Description1 Overview2 Performance-Based Design Concepts3 Design Decision Making
4 Performance Metrics
5 Design Model
6 Applying a Performance Based ProcessFramework
7 Design Information and Sources8 Elements of Design9 Cross-Section Elements10 Intersection Fundamentals
11 Freeways and Controlled AccessFundamentals
12 Interchange Fundamentals13 Context and Facility Type Considerations14 Rural and Natural Areas15 Rural Towns16 Suburban Roadways17 Urban Roadways18 Urban Core Roadways
19 Industrial, Warehouse or Port Roads
Part I
Introduction
Part II
Performance-BasedEvaluations
Part III
Geometric Elementsand Configurations
Part IV
Facility Design inContext
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GB8 Next Steps
1. NCHRP Project 15-77 “Aligning Geometric DesignControls, Criteria and Elements with Roadway Context,Modal Priority and Functional Classification”Funded in NCHRP 2020 program
2. NCHRP Problem Statement for the Development of GB8for NCHRP 2021 Program
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