mobility performance analysis of the ben schoeman …

2014/09/22 SARF/IRF 2014 – South Africa 1 SARF/IRF 2014 | 2-4 September, South Africa

MOBILITY PERFORMANCE ANALYSIS

OF THE BEN SCHOEMAN FREEWAY:

BEFORE AND AFTER GFIP

Raelize DU PLOOY

Aurecon (Pty) Ltd

012 427 3277

[email protected]

SARF/IRF 2014 | 2-4 September, South Africa

2

Outline

1. Introduction

2. Mobility performance measures

3. Gauteng Freeway Improvement Project

(GFIP)

4. Performance of Ben Schoeman Freeway

5. Conclusion


3

1. Introduction

1.1 South African context

– Economic growth

– Increased vehicle ownership

– Urbanisation

– Inadequate public transport

– Backlog in road upgrades and maintenance

Con

ge

stio

n in

So

uth

Afr

ica

Severe Traffic Congestion


4

1. Introduction 1

.2 S

tud

y O

bje

ctive

s

1.2 Study objectives

– Impact of GFIP on traffic congestion for

Brakfontein to Buccleuch interchanges using

mobility performance measures

– Value of using mobility measures to assess

change in traffic conditions over time.

– Impact of e-toll on congestion levels


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2.1 Background

– Definition

• Set of indices to measure traffic congestion

• Based on TRAVEL TIME, taking into account travel distance,

traffic flow, vehicle occupancy

• Relative to an optimum (target or free flow conditions)

• Formalised by Texas A&M Transportation Institute in 2005

– Advantages

• Quantitative values easily compared in time and space

• Improvements well reflected

• Per road section, corridor, route, network

• Able to combine impact of all modes

• Easily understood by public

2.1

Ba

ckg

rou

nd


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2.2 Classification

– Individual measures

• Intensity experience by each road user

• Reliability of arriving on time

– Absolute measures

• Cumulative impact - representative of study area

• Extent of congestion

• Related to economic impact

INDIVIDUAL MEASURES ABSOLUTE MEASURES

Travel Time Index (TTI) Total Delay [Person-Hours].

Delay Per Person km [Person-minutes] Congested Travel [km]

Delay Per Km [Person-hours] Percentage of Congested Travel [%]

Buffer Index (BI) Congested Travel [Person-kms]

Planning Time Index (PTI) Congested Travel [Person-hours]

2.2

Cla

ssific

atio

n


7


2.3 Travel Time Index (TTI) • Compares travel time during peak times to ideal conditions

* VMT : vehicle miles traveled (vehicle km traveled used in this study)

• TTI ≤ 1 : congestion free travel

• 1 < TTI < 2 : Acceptable

• TTI ≥ 2 : Traffic breakdown, congested, gridlock

2.3

Tra

ve

l T

ime

In

de

x


8


• Evaluation of Travel Time Index (TTI)

2.3

Tra

ve

l T

ime

In

de

x


9


2.4 Implementation

• US (since before 2005)

– Government initiative for all major cities

– Comparison annually and between cities

• RSA (2008)

– University Stellenbosch study (Loubser & Bester SATC 2009)

– Comparison of Gauteng (Brakftn to Buccleuch) to Cape

Town (Koeberg to Stellenberg)

• Global Reporting (since 2009, 2010)

– TomTom : based on GPS data

– Annually for major cities in Europe, The Americas, China,

Australia, New Zealand and RSA

2.4

Im

ple

me

nta

tio

n


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3. Gauteng Freeway Improvement Project (GFIP)

3.1 Project info • Launched 2007 by SANRAL,

supported by DOT

• Scope:

– Widening freeways (addition of some 585 km lanes)

– Upgrading interchanges (34 significant upgrades)

– Cross roads improvements

– Median lighting

– Intelligent transport systems

– Open-road tolling system

• Completion Phase 1 : 2012

• Tolling implementation: 1 Dec 2013

3.1

Pro

ject In

fo


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– Ben Schoeman : Brakfontein to Buccleuch Interchange

• Traditionally one of worst

congested road sections

• Included in 2008 study

• Mobility performance calculated

for 2000 – 2007

• Conditions intolerable

– GFIP Upgrades :

• Additional lanes

• Additional ramps

• Widened crossings

• Interchange upgrades

3.1

Pro

ject In

fo

648

OLIFANTSFONTEIN

ALLANDALE

NEW ROAD

SAMRAND

OLD JHB

BUCCLEUCH

BRAKFONTEIN


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3.2

Upg

rad

es: B

en

Sch

oe

ma

n

2

2

2

2

BRAKFONTEIN 2006

3

3

3

2013

2

2

2006

Upgrades: Additional lanes on N1

and ramps


Auxiliary lanes on cross

road.

2

2

3

3

3

4

4

BRAKFONTEIN

OLD JHB ROAD

2013 2006


13


3.2

Upg

rad

es: B

en

Sch

oe

ma

n


Bride widening Auxiliary lanes on cross

road

ANNANDALE RD

2013 2006

OLIFANTSFONTEIN RD

2013 2006

3

3

3

3

4

4

2

2

1

1

Upgrades: Additional lanes on N1 Reconstruction of complete

intersection including 4 new

bridges

5

4


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4. Performance of Ben Schoeman Freeway 4

.1 S

ou

rce

da

ta

4.1 Source Data

– Electronic traffic counts

– Revisits 2008 study – adding indices for 2013

– Most congested conditions

• South bound (PTA – JHB)

• Morning peak

– Traffic flows

• Significant increases between 2007 and 2013

• Annandale - Buccleuch link up to 4000 veh/h)

– Average hourly speeds

• Increase in peak time speeds

• Up to 30 km/h for Old JHB – Samrand link


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4. Study of Performance of Ben Schoeman 4

.1 S

ou

rce

da

ta


16


.2 T

raff

ic g

row

th

4.2 Traffic growth

Length

of link

[km]

AADT [veh] Annual

Growth

[%] 2007 2013

Brakfontein

to Old JHB 3.3 135,305 160,189 2.85%

Old JHB to

Samrand 2.8 112,920 143,612 4.09%

Samrand to

Olifantsftn 3.1 133,745 169,236 4.00%

Olifantsftn to

New Road 3.0 140,508 175,268 3.75%

New Road to

Annandale 4.1 146,963 182.559 3.68%

Annandale to

Buccleuch 4.1 179,277 211,920 2.83%

Weighted Average 144,019 176,472 3.44%


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.3 R

esu

lts o

f d

ata

an

aly

sis

4.3 Results of data analysis

– Travel time indices (TTIs)

• 2013 values compared to previous study (2000 to

2007)

• Case 1: Peak period from 6h00 AM to 9h00 AM

(south bound)

• Case 2: Peak hour from 7h00 AM to 8h00 AM

(south bound)

Cumulative impact

Worst case conditions


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.3 R

esu

lts o

f d

ata

an

aly

sis

Case 1: 6h00 to 9h00 Case 2: 7h00 to 8h00


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.3 R

esu

lts o

f d

ata

an

aly

sis

– Reduction in TTIs for all road sections

– Case 1: 6h00 to 9h00

• 2007: values above critical value of 2

• 2013: all values below 2

• Delays less than in 2000

– Case 2: 7h00 to 8h00

• 2007: values as high as 4

• 2013: all values below 2

– However, still close to critical level


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.3 R

esu

lts o

f d

ata

an

aly

sis

– Actual TTIs and forecasted TTIs (Goba 2006)


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.3 R

esu

lts o

f d

ata

an

aly

sis

– All mobility performance indicators for

south bound AM peak period

Mobility

Performance

Measure

Unit

Average over road

section % change

2007 2013

INDIVIDUAL

TTI - 2.05 1.46 -28%

Delay per hour driven/veh Vehicle-minutes 63 28 -55%

Total Delay Vehicle-Hours 2,856 1,829 -36%

Total Delay Person-Hours 3,427 2,194 -36%

Delay Per Person km Person-Minutes 3.6 1.4 -61%

ABSOLUTE

Congested Travel Person-km 390,364 560,697 44%

Congested Travel km 20.3 20.3 0%

% of Cong. Travel Percent 100 100 0%

Annual Economic cost:

2007: R255 Million

2013: R163 Million


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.3 R

esu

lts o

f d

ata

an

aly

sis

– Impact of e-tolling (1 Dec 2013)

• Impact phased out by May 2014

Flow: Speed:


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5. Conclusions 5

. C

on

clu

sio

ns

• Average hourly peak flows and speeds for

the AM peak have significantly increased;

• Travel Time Indices improved to below

critical levels;

• E-tolling initially impacted on traffic

conditions;

• Mobility performance measures practical

solution of congestion measurement.


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Aknowledgements

• Study conducted with the permission of

SANRAL

• Micros Traffic Monitoring for providing

electronic traffic data

THANK YOU

Raelize DU PLOOY Aurecon (Pty) Ltd

012 427 3277

[email protected]

mobility performance analysis of the ben schoeman …

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