New Jeff Jones, P.E. Tennessee Department of Transportation 1 · 2020. 3. 18. · Jeff Jones, P.E....

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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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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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

4


20182004

1984 1990 1994

20112001

5


Trivia Question

What Color(s) was the Green Book before it was Green ?

6


2011

1984 1990 19942001 2004 2018

7


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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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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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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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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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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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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• 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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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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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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GB7 Photos of “Rural” Context Classes

Rural Context Rural Town Context

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GB7 Photo of “Suburban” Context Class

Suburban Context18


GB7 Photos of “Urban” Context Classes

Urban Context Urban Core Context

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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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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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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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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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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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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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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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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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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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Chapters 6 and 7

Added a section based onNCHRP Report 737

(high to low speed transition zones)

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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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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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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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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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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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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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Chapter 10 - Grade Separations and Interchanges

Added Section 10.9.3.5“Diverging DiamondInterchanges (DDIs)”

AKA “Double Crossover Interchanges”

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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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Questions ?

JEFF JONES, ASSISTANT CHIEF ENGINEERTENNESSEE DEPARTMENT OF [email protected]


GB8GB1

The AASHTO Green Book, 8th Edition (GB8)

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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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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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Evaluations



Design



Part IVFacility Types


Green Book 8th Edition Vision(TCGD Meeting in Reno)

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Part IIntroduction



Evaluations



Design



Part IV

Facility Types


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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Questions ?

JEFF JONES, ASSISTANT CHIEF ENGINEERTENNESSEE DEPARTMENT OF [email protected]

New Jeff Jones, P.E. Tennessee Department of Transportation 1 · 2020. 3. 18. · Jeff Jones, P.E....

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