7. interchanges.pdf

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RTA Supplement Guide to (Austroads)______________________________________________________________________________________________

UNCONTROLLED WHEN PRINTED 1 (27 pages)

RTA Austroads Guide

SupplementsPublication Number: RTA/Pub.11.281Publication date: 4 July 2011 Supersedes : Nil

RTASupplementto

AUSTROADSGUIDETOROADDESIGN

Part4C:Interchanges(ReleasedAugust2009)

General

Austroads has released the Guide to Road Design Part 4C: Interchanges and all

road agencies across Australasia have agreed to adopt the Austroads guides toprovide a level of consistency and harmonisation across all jurisdictions. This

agreement means that the new Austroads guides and the Australian Standards,hich are referenced in them, will become the primary technical references forw

use within the Authority.

his supplement is issued to clarify, add to, or modify the Austroads GuidetoTRoad Design Part 4C: Interchanges

The RTA NSW accepts the principles in the Austroads GuidetoRoad Design PartC: Interchangeswith variations documented in this supplement. Theseari

4v

ations fall into two categories:

RTA Complementary Material: RTA Design Reference Documents referencematerial that complements the Austroads Guides. These documents include

RTA Manuals, Technical Directions and/or other reference material and areto be read in conjunction with the Austroads Guides.

RTA Departures: RTA road design practices that depart from the AustroadsGuides.

ee also the RTA Supplements for the other parts to the Austroads Guide to RoadSDesign Series and the RTA Supplements to the other Austroads Series.

ll Reference Documents mentioned in this part should be checked against the

TA Design Reference Documents.

A

R


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DocumentInformation

Title: RTASupplementto

AUSTROADSGUIDE

TO

Part4C:Interchanges

ReleasedAugust2009

Branch/Section: Road Design Engineering / Technology Standards(Road)

Author: Technology Standards (Road)

Contributors: Technology Standards (Road)

Approver: RTA Austroads Committee

Audience: Public

DateofEffect: 4/07/2011

NextReviewDate: 30/05/2013

DocumentNumber: RTA/Pub.11.281

Keywords: Supplement, Austroads, Part 4C, Interchanges

DocumentHistory

Version Date ReasonforAmendment Pag

No.

e Editor

1.0 4/07/2011 Published All Technology

Standards(Road)

For enquiries and further issues to be added to this supplement email

Austroads Supplements

mailto:[email protected]:[email protected]


3/27


Reference

SectionRTAEnhancedPractice,ComplementaryMaterial,or

Departures

Date

General RTApracticeforActs,RegulationsandRules.

RTArole/purpose:

Transport Administration Act 1988

RoadClassification/RoadAuthorityPowers:

Roads Act 1993

Roads Regulation 2008

RoadRules/enforcementpowers:

Road Rules 2008

Road Transport (General) Regulation 2005

RTAcomplementarymaterial:DesignReferenceDocuments


4STRUCTURES

nsert 4.9 Safety Screening of Bridges after Section 4.8Services on Structure

CONTENTS

I

7SIGHTDISTANCE

7.5

Replace Safe Intersection Sight Distance with Minor Road

Terminals as new heading for section 7.5

11.3EntryRamps

11.3.2 Single Lane Entry

Replace Single Lane Entry with Entry Ramp (Type 1)

11.3.4 Entry with Auxiliary Lane

Replace Entry with Auxiliary Lane with Entry Ramp (Type 2)

APPENDIXB

Delete entire Appendix B Not used

TABLES

Table 6.1

Insert range of after Recommended and before minimum
http://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/subordleg+606+2005+cd+0+Nhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/sessionalview/sessional/sr/2008-156.pdfhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+Nhttp://www.legislation.nsw.gov.au/maintop/view/inforce/act+109+1988+cd+0+N


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design speeds

FIGURES

Figure 7.3

tical curve radius with K values before requiredReplace Ver

for sight

sFigure 11.1Delete An example of before singlelane exit

Figure 11.2

Delete preferred and acceptable treatmentsFigure 11.6

Replace figure title with Entry Ramp (Type 1)

igure 11.7eplace figure title with Entry Ramp (Type 2)

FR

Section1

Section1.1

INTRODUCTION

Purpose

No amendments

Section1.2 ScopeofthisPart

Insert Forms of interchange are described in Section 3. afterlast paragraph, immediately before Section 1.3 Road Safety

Section1.3 RoadSafety

No amendments

Section1.4 RoadDesignObjectives

No amendments

Section1.5

Traffic

Management

at

Interchanges

No amendments

Section1.6 SafetyPerformanceofInterchanges

No amendments

Section1.7 TrafficCapa

Paragraph 4

cityofInterchanges

Insert after paragraph 4

LevelofService

LevelofserviceA. A condition of free flow in which individual

drivers are virtually unaffected by the presence of others in thetraffic stream. Freedom to select desired speeds and to

anoeuvr within the traffic stream is extremely high, and the

eneral level of com

m e

g fort and convenience provided is excellent.

LevelofserviceB. In the zone of stable flow where drivers stillhave reasonable freedom to select their desired speed and to

manoeuvre within the traffic stream. The general level ofomfort and convenience is a little less than with level of service

.

c

A

LevelofserviceC. Also in the zone of stable flow, but most


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drivers are restricted to some extent in their freedom to selecttheir desired speed and to manoeuvre within the traffic stream.

he general level of comfort and convenience declinesoticeably at this le

Tn vel.

Levelof

service

D. Close to the limit of stable flow and

approaching unstable flow. All drivers are severely restricted in

their freedom to select their desired speed and to manoeuvrewithin the traffic stream. The general level of comfort and

onvenience is poor, and small increases in traffic flow will

enerally cause ope

c

g rational problems.

LevelofserviceE. Traffic volumes are at or close to capacity,and there is virtually no freedom to select desired speeds or to

anoeuvre within the traffic stream. Flow is unstable and minor

isturbances within wn.

m

d the traffic stream will cause breakdo

LevelofserviceF. In the zone of forced flow, where the

amount of traffic approaching the point under considerationxceeds that which can pass it. Flow breakdown occurs, andueuing and delays result.

eq

Section1.8 StagedDevelopmentofInterchanges

StagingInterchangeDevelopment

Paragraph 1

Replace Most with Some at the beginning of the paragraphParagraph 4

Section1.8.1

Insert Access and Traffic Switches to become 6th and 7th dotpoint respectively after 5th dot point overall road network

development in the vicinity

Section1.8.2 FlexibilityandCNo amendments

onstructability

Section2 DESIGNCONSIDERATIONSPROCESSANDPRINCIPLES

Section2.1 General

No amendments

Section2.2 DesignConsider

nts

ations

No amendme

Section2.2.1 DesignInformation

idesParagraph 1Insert , 2009l after (Austroads 2009a and before ) prov

Paragraph 2

Replace Key with Other before aspects that require

Section2.2.2 DesignControls

No amendments

andCriteria


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Section2.2.3 StormwaterDrainage

Paragraph 3, 5thdot point

Replace to minimise maintenance costs with to minimise

ts separately, as a 6th dot pointmaintenance cos

Section2.2.4 LandscapeDeveNo amendments

lopment

PublicTransportFacilities

Paragraph 1Delete To achieve targets for increased public transport

atronage, and, at the beginning of the paragraph and hencep

commence paragraph with To address

Replace is with may be in the first sentence after transportsystem and before required

Section2.2.5

Paragraph 2

Insert Intelligent Transport Systems (ITS) and Bus early

starts as an additional dot point to become 10thand 11thdotpoints

Section2.3 DesignProcess

Insert a new sentence This section supplements therequirements of Austroads 2009l , immediately before the 1st

sentenceSection2.3.1 ReviewPlanningReports

No amendments

Section2.3.2 DesignBrief

No amendments

Section2.3.3 PreliminaryDesign

No amendments

Section2.3.4 DetailedDesignStage

No amendments

Section2.4

Section2.4.1

Principles

InterchangeElements

Paragraph 1Insert bridge structure/s as an additional dot point to become

the 4thdot point.

InterchangeUniformityand

2.4.2

Spacing

Section number

32 with Replace 2.4.

Section2.4.32

Spacing subheading

Paragraph 3Insert and tapers after exit ramps and before .


7/27



Paragraph 3, 1st dot pointReplace AS 1742.15; MOTSAM Part 3, (Transit NZ 2004b) and

jurisdictional guides with RTA Supplement to the Austroads,t series after (refer toGuide to Traffic Managemen

Paragraph 3, 2nd dot pointReplace 200m per lane change, whilst cars desirably require

150m per lane change. with a longer length in which to change

d are determined from Austroadslanes. The lengths require2009c. after heavy vehicles require

Paragraph 4, 1st Sentence

Replace the minimum with a desirable after is that and

ng ofbefore spaci

Paragraph 4

Insert Whilst the provision of such lengths is generally

impractical in urban areas, a minimum of 1.5km to 2.0km shouldor urban freeways (refer Austroads 2007)., afterbe provided f

the 1st dot point and before the 2nd dot point.

Paragraph 7

Replace In urban areas, spacing above about 4 km would not be

expected. In rural areas a spacing greater than about 12kmwith

Spacings above 4 km in urban areas and 12 km in rural areas

after local road network. and before should be carefully

Section

3

FORMS

OF

INTERCHANGETrafficConsiderations

Figure 3.3In both views (a) and (b) Delete terminal and insert gore in

ht hand side of Figure in four locations, so that newnotes at rig

notes read Freeway entry ramp gore

Figure 3.4

In both views (a) and (b) Replace all instances of terminal withgore ;

Figure 3.5In view (a) Replace Semidirectional with Semidirect in

note to read Semidirect exit rampIn view (b) Replace Semidirectional with Semidirect in

t exit ramp and Semidirecttwo notes to read Semidirec

rampfter Figure 3.4,Paragraph 1 a

S

ection3.1

2nddot point

Replace Directional with Direct at beginning of sentencebefore ramps


8/27

RTA Supplement Guide to (Austroads)_________________ ______________ _______________________________________________________________


3rddot pointReplace Semidirectional with Semidirect at beginning of

efore rampssentence b

Figure 3.5Replace directional with direct before ramp in label for

Figure 3.5

Figure 3.5Replace directional with direct before ramp in note to read

Direct ramp

Replace terminal with gore in notes in two locations, so that

new notes read Freeway entry ramp gore (right side) andFreeway exit ramp gore (right side)

Section3.2 OtherConsideraNo amendments

tions

Section3.2.1 General

No amendments

Section3.2.2 UnderpassorO

No amendmentsverpass

Section4 STRUCTURES

General

Paragraph 2

Delete NZ Bridge Design Manual (Transit NZ 2003); and NZy Control Manual (Transit NZ 2004a).State Highwa

Section4.1

Paragraph 3

Insert If a bridge must be on a curve then it is far preferable for

the entire bridge to be within the curve and positioned to avoid

any applicable transitions. at the end of the paragraph after

complexity of structures.Section4.1.1 TypesofStructure

Paragraph 1

Insert safety screening, after sign structures and before andsafety barriers

FormofStructure

Paragraph 2

Delete it is suggested that in last sentence after In these

cases and before a barrier capable

Section4.2

Replace should with must in last sentence after heavyvehicles and before be provided


9/27



Paragraph 3

Replace The bridge pier on the median may with Bridge piers

located on medians generally after for economy. and before

need protection by

Replace will need to with must after barriers, which andbefore be sufficiently strong

Insert and buses after prevent trucks and before from crashing

into the pier

Insert This requirement is mandatory within the hazard

identification corridor (Austroads 2009e). at end of 2ndsentence after the pier. and before The form of

Insert for the bridge after structure adopted and before willdepend on the circumstances

Section4.3 Cross-sectionso

No amendments

nBridges

Section4.4 Pedestrian/Cyc

No amendments

listGradeSeparations

Section4.4.1 General

No amendments

Section

4.4.2

Safety

Barriers

at

Pedestrian

BridgesParagraph 1

Replace clear zone with hazard identification corridor(Austroads, 2009e)

Section4.5 Culverts

Paragraph 1

Replace Culvert end walls within the clear zone should bedriveable, or alternatively, the culvert should be extended

d the limit of the clear zone, or protected by a safetybeyonbarrier

with

Culvert end walls should, where possible, be located outside ofthe hazard identification corridor. Should this not be possible

the culvert end walls should be drivable and/or protected by aafety barrier. after drainage authority and before (refer to

e Guide

s

th

Section4.6 RetainingWalls

No amendments


10/27



Section4.7 WildlifeCrossin

No amendments

gs

Section4.8 ServicesonStru

No amendments

cture

Section4.9 SafetyScreening

w section after Section 4.8 Services on Structure.Add ne

Insert

Consideration must be given to the risk imposed on motoristsby objects accidently falling or being illegally thrown from

overhead bridge structures at interchanges. The stance of the

Roads and Traffic Authority of NSW is currently to undertake a

risk assessment to determine the need to place safety screeningon bridges (RTA, 2002). The referenced document includes a

isk assessment matrix for this purpose and additional

nfo

r

i

rmation including:

the speed of the impacted vehicle is a significant factor,therefore high speed roads accord a high priority

new interchanges are expected to incorporate facilities thatmay be required during the life of the structure

all overbridges over motorways, restricted access roads ormajor public roads, which are within 2km of a school, club or

hotel would invariably warrant protection.

After the section title.

Section5 CROSSSECTION

Section5.1 MajorRoadand

No amendments

MinorRoad

RampCrossSection

NumberofLanesonRamps

Exit Ramps

Paragraph 2, 1st dot point

fter the last word rampInsert ,or a

Paragraph 3

Replace two lanes to one lane with one lane to two lanesafter The transition fromand before at the nose

Section5.2

Section5.2.1

Entry Ramps

Paragraph 2, 1st dot point


11/27



Delete the length of a single lane ramp exceeds 300m on a levelgrade and so that 1st dot point begins with a truck

accelerating

Delete rest at after accelerating from and before the rampterminus

Replace terminus with terminal after the ramp and before

would not be

Insert ,or after the last word ramp

RampLaneWidths

Paragraph 1, 3rd sentence

Delete colour and/or after shoulders with and beforetexture differing

Insert Under special circumstances the shoulders may be

reduced but the total carriageway width should not be less than5.5m. at the end of the 4th sentence and after a similar effect.

Table 5.1

Lane width columnReplace 4.0 with 3.5

Section5.2.2

Paragraph 3

ce the lane widths should allow for a semitrailer and aRepla

car to travel side by side

with

the width of the left lane should allow for a semitrailer to

travel adjacent to a car occupying the right lane after twolane

loops and before as a minimum

Section5.3 ClearancesonM

No amendment

ajorRoad

s

Section6 DESIGNSPEED

Section6.1 General

No amendments

Section6.2 MajorRoad

2nd dot point

Delete entire 2nd dot point


12/27



Paragraph 2

Delete the entire Paragraph 2 and insert to allow traffic moving

onto the major road to merge at the operating speed of that

road. as a new 2nddot point

Section

6.3

Minor

Road

Paragraph 3

Delete Paragraph 3

Ramps

RampDesignSpeed

Paragraph 6

Replace these ramp types with ramps of the first type after

design speeds and before as a functionminimum

Table 6.1

Table Heading

Insert range of after Recommended and before minimum

design

Section6.4

Section6.4.1

Replace entire Table 6.1 with Table 7.2.4(a) NAASRA 1984,

including source in footnote beneath the table

Section6.4.2 OtherConsiderations

Paragraph 1, 8th dot point

ce large decreases in speed are often required to meet theReplaneeds of the intersection at the terminal.

with

speed should be reduced progressively and safely to amagnitude that is consistent with the ramp alignment and the

ramp terminal conditions. after Along exit ramps and beforeIt is desirable

Section7 SIGHTDISTANCE

General

Paragraph 1

psInsert (1.1m to 0.2m) after all ram

Insert (1.1 to 0m) after exit nose

Insert (1.1m to 0m) after entry ramps

Insert (1.1m to 1.1m) after on the entry ramp

Insert (1.1m to 0m) after at ramp terminals

Insert (1.1m to 0.65m) after at the terminal)

Section

7.1

Insert (1.1m to 1.25m) after off ramp approach.


13/27



Section7.2 StoppingSightD

No amendments

istanceontheMajorRoadandMinorRoad

ExitRampNose

Paragraph 2

Insert Additionally, the exit ramp should be graded byextension of the freeway crossfall to a point 60 m beyond the

the end of the Paragraph 2 after the exitexit nose. at

treatment.

Paragraph 3

1st sentenceDelete entire

Paragraph 4

Delete outside and insert auxiliary after centre of the andbefore lane on the

Delete on the freeway after the outside lane and before to

the centre

Replace closest to the taper with (refer Figure 7.1(c)) after

the ramp lane and before The object height

Delete entire column headed Exit with taper only (Figure 7.1

(b))

Table 7.1ew column headed K Values for CrestInsert in Table 7.1 a n

Curves with values

60 = 131.4 and 65.5

80 = 240.5 and 109.2

100 = 356.4 and 172.8

110 = 436.8 and 210.1

120 = 495.0 and 251.0

130 = 589.1 and 295.6

Figure 7.1

Delete middle section of Figure 7.1 (b) Plan exit taper

Section7.3

Figure 7.3

Replace Vertical curve radius with K values in the figurelabel after Figure 7.3: and before required for sight


14/27



EntryRampNose

Paragraph 6, 3rd dot point

Replace so that the right edge of the ramp lane is within 0.6m of

the level of the edge of the left traffic lane of the major road (e.g.

freeway) with by extension of through road (e.g. freeway)after should be gradedcrossfalls

Section7.4

Table 7.2

Column headed Approach to nose 2 rows

Replace 0.1m with 0.0m after height to and before object

height)

SafeIntersectionSightDistance

Replace subheading Safe Intersection Sight Distance with new

or Road Terminalsheading Min

Section7.5

Paragraph 1

Replace entire paragraph with Sight distances should be basedon the reaction times described in Section 5.2.2 (Austroads

2009a)

Section8 HORIZONTALALIGNMENT


No amendments

Section8.2

Section8.2.1Minor

Road

Curvature

No amendments

SpreadDiamondInterchanges

Paragraph 1

Replace on each approach to the structure with on the

approach to the ramp terminals (or intersections) on the minorroad after medians are developed and before to allow for

Section8.2.2

Paragraph 8

Replace 2.5% with 3% after be limited to and before andused only

Section8.3 Ramps

8.3.1 General

Paragraph 2

Insert To enhance visual awareness of an exit ramp it is alsodesirable that the ramp grade be greater than the grade of the

freeway, given the grades should not split until a point 60m

beyond the nose. at the end of the Paragraph 2 after of heavy


15/27



vehicles.

GeometricRequirements

Paragraph 1

able 8.1 with Table 7.5 in Austroads 2009a atof 1st sentence before provides a guideReplace Tbeginning

Section8.3.2

Table 8.1

Delete entire table

SystemInterchanges

Paragraph 1, 2nd sentence

Replace a high speed with higher speeds after are designed

for and before (80km/h)

Replace 80 with 70 in brackets at the end of the 2nd

sentence.

Section8.3.3

3rd sentence

Replace 70 with 55 in brackets at end of 3rd sentence.

ServiceInterchanges

Diagonal ramps, Paragraph 6

Replace often with sometimes after It is and beforeimpractical to provide

Replace and hence with . Normally after long entry ramps

and before they should generally

Delete generally after they should

range

and before be in the

Replace As a general principle it is

with

In some instances, it may be after 300m to 450m and beforepreferable to provide

Insert full stop to end sentence after road after on the major

and before (refer to Section 5

Section8.3.4

Exit loop ramps subheading,

Paragraph 1

Replace Where exit loops are

with Exit loop ramps should only be used where other types of

ramp are not practical due to space restrictions or where thereare large volumes of right turning traffic. They are generally at


16/27



beginning of 1st sentence and before used at service

Paragraph 2

Delete entire Paragraph 2

Section9 VERTICALALIGNMENT


No amendments

Section9.1.1 GradingOption

No amendments

s

Section9.1.2 GradingContro

No amendments

ls

Section9.2

Section9.2.1Minor

Road

ClosedDiamond

New Paragraph 6

Insert Grading of entry and exit ramps independent of thefreeway grading should not commence on the ramp proper prior

to a point 60 m from the nose (refer Section 7.3 and Section

7.4). to create new additional paragraph.

Section9.2.2 SpreadDiamond

Paragraph 3, 3rd dot point

Replace SISD with ASD at beginning of 3rd dot point

Section9.3

Section9.3.1

Ramps

RampGradients

No amendments

forSystemInterchanges

Section9.3.2 RampGradients

No amendments

onServiceInterchanges

Section10 RAMPTERMINALSATMINORROADS

RampTerminalLocation

Paragraph 4

Paragraph 4

s

Delete entire

Section10.1

Paragraph 5


Section10.2 RampAlignmentatMinorRoadTerminals

Section10.2.1 ExitRampAlign

No amendments

mentatMinorRoadTerminals

Section10.2.2 EntryRampAlig

No amendments

nmentatMinorRoadTerminals


17/27



RampTerminalatMinorRoad

Figure 10.4

: Applicable at rural nonsignalised intersections as

Figure 10.4

Insert Note

footnote for

Section10.3

Figure 10.5Insert additional note 3. Applicable at rural nonsignalised

intersections

Section11 RAMPTERMINALSATTHEMAJORROAD

Section11.1 General

No amendments

ExitRamps

Single-laneexits

Paragraph 1Replace typical single lane exits for interchanges for use onfreeways and major divided roads with a singlelane exit

ramp after Figure 11.1 shows and before The auxiliary lane

Delete from (Figure 11.1 (a) to end of last sentence endingwith a simple diverge.

Paragraph 2

Delete also after auxiliary lane and before emphasises the

D

a

elete the entire last sentence beginning with For the same

nd ending with in Commentary 4.

3rd Paragraph


Figure 11.1

Replace Figure 11.1 with alternative Figure 11.1 as shown below

Section11.2

Section11.2.1

Delete An example of at the beginning of the label for Figure

11.1 before single lane exits


18/27


Delete An example of before singlelane exits in label forFigure 11.1

Paragraph 4

Replace the entire last sentence with

The deceleration distance should be sufficiently long to allow a

driver to make the appropriate change in speed between themajor road and the turning road. Deceleration may end in a

complete stop, such as at traffic signals at the termination with

the minor road. In such a case storage length behind the stopline will need to be allowed for. The deceleration distance (Dd)

is shown in Figure 11.1 whilst the values of Dd are provided in

Table 11.1 together with adjustments for gradient.



19/27


Table 11.1

Insert additional note 4. Values shaded red in the table are not

recommended without associated speed reduction treatments.

Figure 11.2

Replace Figure 11.2 with alternative Figure 11.2 as shown below

Delete preferred and acceptable treatments at end of label

for Figure 11.2

Insert Note: Details can be reversed for single lane exit with

two lane ramp and right diverge. as footnote in Figure 11.2

Two-laneExits

Figure 11.3

Insert See Note 2 in Figure 11.3 along the exit taper that

commences the auxiliary lane.

Insert See Note 3 in Figure 11.3 at the angle where the

r.auxiliary lane meets the beginning of the 1:15 ramp exit tape

Delete 2m(2) in Figure 11.3 shown as a dimension on the

through freeway shoulder.

Insert Notes as a heading for the following four footnotes

Delete (1) and insert 1. Denoting the 1st footnote

Section11.2.2

Replace (2) Indicative only. Refer to the Guide to Road Design

Part 3: Geometric design (Austroads 2009a).

with

2. Exit taper to be in accordance with Figure 11.1

3. Use of a horizontal curve to join the auxiliary lane to the 1:15ramp taper is mandatory and is to be in accordance with Figure

11.1



20/27



Insert 4. to commence the 4th footnote which is to re

For nose detail, refer to Figure 11.1 Nose detail B.

ad

Section11.2.3 ExitstoTwoHigh-speedRoadways

Paragraph 1, 2nd sentence

Insert or zip diverge. at the end of the 2nd sentence after a

major fork.

LaneDropatanExit

Figure 11.5

Insert See Note 1. at the angle where the exit ramp leaves the

through freeway.

Insert Note as a heading for the following two footnotes and

delete existing Note:

Insert 1. Exit ramp conditions must be in accordance with

Figure 11.1 as 1st footnote.

Section11.2.4

Insert 2. T = taper length based on a rate of lateral shift of

0.6m/s as 2nd footnote.

Section11.3

Section11.3.1

EntryRamps

General

Paragraph 2

Delete on high speed roads (operating speed > 80 km/h) after

At all interchanges

Replace to enable after an auxiliary lane with (i.e. a length

parallel lane). This Enablesof

Delete At interchanges provided beyond the nose (the l

sentence of paragraph two)

ast

Insert In all instances of entry ramp design, the preferred

option should incorporate an auxiliary lane as shown in Figure11.7(a). That treatment (Type 2) provides more flexibility to

cater for situations where vehicle acceleration is theetermining factor for entry conditions and provides paralleld

running for safer merging.

An entry ramp layout incorporating a simple merge as shown in

Figure 11.6 provides a less favoured layout. This may beconsidered where anticipated traffic volumes are relatively low

in number resulting in frequent merging opportunities or there

are other extenuating circumstances.. as an additionalparagraph after the Paragraph 2.


21/27


22/27


23/27


Replace Table 11.2 with

Da(m)Designspeed of

road

enteredAccelerat ion Distance

(where design speed from ramp terminal is)

(km/h) 0 20 30 40 50 60 70 80

70 165 150 140 125 95 55 - -

80 235 220 210 195 165 125 75 -

90 330 315 305 290 260 220 170 95

100 450 435 425 410 380 340 290 220

110 610 595 585 570 540 500 450 380

120 795 780 770 755 730 700 660 600

Notes:

(1) This table applies where the design speed of the road being entered is greater that thedesign speed prior to the nose on the entry ramp. This speed differential is generally causedby either a horizontal curve or traffic control signals in the vicinity of the ramp terminal on the

joining road (refer Section 11.3.3).

(2) Davalues are to apply to the acceleration distance designated on Figures 11.6 and11.7(a).

(

S

3) Davalues are for level grade and must be adjusted for grade using Table 11.3.

ource: Adapted form RTA (1999) and RTA (2000)

Replace Table 11.3 with

Notes:

(1) Ratio from this table multiplied by length in Table 11.2 gives length of speed change laneon grade.Source: Adapted form RTA (1999) and RTA (2000).



24/27


Replace Figure 11.9 with

Section11.3.4 Two-laneEntry

No amendments

Section11.3.5 LoopRamps

No amendments

Section11.3.6 MergingofHigh

No amendments

speedMajorRoads

Section11.4

Section11.4.1

RampTrafficSignals

General

Paragraph 1

Replace Section 6.9 of after Reference should also be made to

with to the RTA Supplements to

Section11.4.2 CapacityAnalys

No amendments

is

Section11.4.3 GeometricandLayout

No amendments

Design

RAMPSONTWO-LANETWO-WAYFREEWAYS

Figure 12.1

(a) Layout

Note at Exit ramp to read Exit ramps are generally located inthe vicinity of opposite the entrance ramp and usually not as

shown in this layout

Insert Notes as a headin

s

g for the following four footnotes

1. Taper length

2. Diagonal marking

3. Median width

Insert 4. Length of parallel lane L based on 4 seconds of travel

time as additional 4th footnote

Section12

Insert 5. Exit ramps are generally located opposite the entrance

ramp and not as shown

Section13

Section13.1

PEDESTRIANS

General



25/27



No amendments

Section13.2 BusPassengers

No amendments

Section14

Section14.1

CYCLISTS

GeneralNo amendments

Section14.2 TreatmentatIn

terchanges

No amendments

Section14.2.1 CyclistsRequire

dtoExitandRe-enterFreeway

No amendments

Section14.2.2 GradeSeparatio

nofRampsforCyclists

No amendments

Section14.2.3 AlternativeRou

No amendments

tes

PAVEMENTMARKING,SIGNSANDLIGHTING

General

Paragraph 5ard ASInsert RTA Supplement to before Australian Stand

1742

Section15

Section15.1

Insert RTA Supplement to before Guide to TrafficManagement

Section15.2 KeyConsiderat

ions

No amendments

Section15.3 LightingofInte

No amendments

rchanges

Section16

Section16.1

LANDSCAPINGA

General

NDSTREETFURNITURE

No amendments

Section16.2 LandscapeDeve

lopment

No amendments

Section16.3 RoadSafety

No amendments

Section17 OTHERCONSIDERATIONS

Section17.1 AccessintheVicinityofInterchanges

Section17.1.2 AccesstotheMinorRoad

Paragraph 2

Replace An expressway with A freeway at the beginning of

the Paragraph 2.

Section17.2 ServiceCentres

No amendments

REFERENCES


26/27



Insert Austroads 2009l Guide to Road Design: Part 8: Processocumentation by Bernard Hammonds, Don Hicks and Drand D

John McLean Sydney NSW

after

Austroads 2009k, Guide to

Insert NAASRA 1984 Grade Separated Interchanges, A Design

, National Association of Australian State Road Authorities,alphabetical position

GuideSydney, NSW in the correct

after

Austroads 2009l Guide to

Insert RTA 1999, Road design guide, section 4, intersections

grade, May 1999 Issue 1.0, Roads and Traffic

Authority, Sydney, NSW. in the correct alphabetical positionafter Queensland Department

at

Insert Roads and Traffic Authority of New South Wales 2002,Technical Direction TD 2002/RS02: Policy for Safety Screening

of Bridges, Road Safety and Road User Management Section,

Road Network Infrastructure Branch, Roads and TrafficAuthority of New South Wales, Sydney. in the correct

alphabetical position after RTA 1999

AppendixA

EXAMPLE

OF

RAMP

SPEED

ANALYSIS

Paragraph 2

Insert This concept is based on the Operating Speed Model(refer Section 3.5 of Austroads 2009a). after the R30 curve

m decreaseand before The maximu

Additional Paragraph 6

Insert Designers should be aware that where the Operating

Speed Model is implemented, it is important that appropriate

superelevation transitions must apply. as an additionalaragraph after the Paragraph 5.p

AppendixB RAMPTERMINAL

elete Appendix B

LOCATION

D

AppendixC EXAMPLESOFR

No amendments

AMPSIGNALLAYOUTS


27/27


Commentary

1

C1.1

STAGEDDEVELOPMENTOFROADS

Paragraph 2

Replace expressway with freeway after is, by creating and

before conditions initially.

C1.2

StagedDevelopm

No amendmentsent

of

Interchanges

C1.2.1 GeneralConside

No amendments

rations

C1.2.2 FactorstoCons

ider

No amendments

Commentary

2

No amendments

Commentary

3

No amendments

Commentary

4Delete entire Commentary 4 Not used

Commentary

5No amendments

Commentary

6

No amendments

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