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Austroads

Guide to Road Design

Dr Owen ArndtQld Dept of Transport & Main Roads



OverviewThe Guide to Road Design Series:

Is a set of comprehensive guides to promote safe, economical and efficient road designs

Covers most aspects of road design, including– Geometric elements– Drainage– Roadside features

Is intended to replace guides from individual jurisdictions– Promote standard practice– Avoid duplication– Companion documents may be developed to cover specific

local design situations

Is closely related to the Guide to Traffic Management Series

– Needs to be considered in conjunction with all of the other Austroads guides



Guide to Road Design – structurePart 1 Introduction to Road Design (23 pages)Part 2 Design Considerations (38 pages)Part 3 Geometric Design (298 pages)Part 4 Intersections and Crossings – general (144 pages)

Part 4A – Unsignalised and Signalised Intersections (235 pages)Part 4B – Roundabouts (102 pages)Part 4C – Interchanges (110 pages)

Part 5 Drainage Design (210 pages)Part 6 Roadside Design, Safety and Barriers (284 pages)

Part 6A – Pedestrian and Cyclist Paths (113 pages)Part 6B – Roadside Environment (102 pages)

Part 7 Geotechnical Investigation and Design (81 pages)Part 8 Process and Documentation (72 pages)

Total (~1800 pages)



Organisations Represented

State road authorities (6 members)

Territory road authorities (2 members)

New Zealand Transport Agency

Assocation of Consulting Engineers, Australia

Australian Bicycle Council

Australian Local Government Association

ARRB

Organisations represented here will be the users of the guide (potentially anyone undertaking road design in Australia and New Zealand)



Development of the GuideSource material

Existing Austroads guides where the material is still up to date and relevant, including

– Urban & Rural Road Design Guides – Guide to the Hydraulic Design of Bridges, Culverts & Floodways– Several of the Guides to Traffic Engineering Practice

eg Parts 5, 6, 13 & 14

State road authority documents, where material is more up to date

Other documents– eg Storm Drainage Design in Small Urban Catchments

Some new material developed

Authors

ARRB

Particular state road authority members

Consultants



ProcessAuthor / revise draft document

Panel members review and provide comments

Major comments are discussed at panel meeting

Document sufficiently completeNo

Yes

Seek endorsement

Publish



Format of the Guide

Body contains the bulk of the design criteria

Appendices contain additional design criteria & examples

Commentaries contain supporting material / background information

Material in one place only ie not duplicated between parts or between other series

– High level of cross referencing used



Format of the Guide

For Parts 3 and 4 (the bulk of the geometric design criteria)

Values / criteria suitable for new roads (greenfield projects) placed in body

– Normal Design Domain

Values / criteria generally only suitable on existing roads (brownfield projects), where technically justified, placed in Appendix A

– Extended Design Domain

No guidance provided for the design of existing roads (brownfield projects) where Extended Design Domain criteria cannot be achieved

– Design Departures / Exceptions– To be placed into a separate document?



What’s new

Part 3 - New criteria for minimum size sag vertical curves, adapted from VicRoads• Use of ‘K’ values exclusivelythrough the guides



What’s newPart 3 - New criteria for application of superelevation• reduction in the number of charts



What’s new

Parts 3 & 4 - Improved guidance on public transport facilities, from

• VicRoads• WA MRD



What’s new

Parts 3 & 4 - Updated sight distance models based on work from Qld DT&MR

• New ‘constant’decelerationrates

• New vertical heightconstants

• More emphasis ondesigning for trucks

• Additional guidancefor sighting over andaround roadside barriers



What’s new

Parts 3, 4 and 6 - Additional criteria for on-road and off- road cycle facilities, based on RTA and VicRoads work



What’s new

Part 4B - Additional methods to provide for cyclists through roundabouts eg physical separation through use of concrete splitter islands, based on RTA work Concrete

splitter island



What’s new

Desired driver speed on the

fastest leg prior to the roundabout

(km/h)

Minimum central island radius of a

single-lane roundabout (m)

Minimum central island radius of a

two-lane roundabout (m)

Speed reduction treatments

required prior to the entry curve a

Absolute Desirable Absolute Desirable

≤

40 b 5 d 10 8 12 No

50 b 8 11 8 12 No

60 c 10 12 14 16 No

70 c 12 18 18 20 No

80 c 14 22 20 24 Desirably

≥

90 c 14 22 20 24 Yes

Part 4B - Guide for selecting the minimum central island radius for a circular roundabout, based on Qld DT&MR research



What’s newPart 4B - New criteria for speed control at roundabouts –entry path curvature, based on Qld DT&MR



What’s new

Part 5 - new material on the design of pollution treatments- worked examples on various aspects of drainage design



What’s new

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0.8

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n of

err

ant v

ehic

les

that

will

reac

h ha

zard

(Pi)

Distance of hazard from edge of travelled way(m)

2015100 25

0.2

0.6

0.7

0.5

0.3

0.1

5

0.9

1.0

30

Un-divided roads

Divided roads

Part 6 - New material on warrants and location of roadside safety barriers, based on research and testing by RTA



What’s new

Part 6B - New material on environmental aspects of road design eg fauna sensitive road design, noise control



What’s new

Part 7 - Guidance for road designers on geotechnical issues

Part 8 - Guidance for road designers on design processes and documentation

Client

Framework ofSuppliers

Sub- contractors

Contractor B

DesignerContractor A*

ECI Agreement D&C



Promotion of the new guide

Each local jurisdiction to produce a strategy for transitioning to the new guides. Road designers will be advised through

– Departmental policy and correspondence

Location of material in hard copy and on local websites

– Promotion at local forums and workshops

Provision of training courses by ARRB



Thanks

Thanks to

– All road design review panel members– Authors, including

Gary Veith (ARRB)

David Barton (VicRoads)

Bernard Hammonds (RTA)

Rob Grove (WA MRD)

Owen Arndt (Qld DTMR)– Project managers, including

Michael Tziotis (ARRB)

David Barton (VicRoads)

Noel O’Callaghan (SA DTEI)

Rob Grove (WA MRD)

Graeme Nichols (Tas DIER)

Owen Arndt (Qld DTMR)

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