evaluation of a performance-based standards … 2014 | 2-4 september, south africa evaluation of a...

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

Evaluation of a Performance-Based Standards

approach to heavy vehicle design to reduce

pavement wear

Paul Nordengen Research Group Leader

Council for Scientific and Industrial Research

Michael Roux Senior Researcher

Council for Scientific and Industrial Research

www.IRFnews.org

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

1.Background and Introduction

2.Objectives

3.Road Transport Management System (RTMS)

4.Performance-Based Standards Approach

5.Evaluation of Results (Demonstration Project)

2

CONTENTS

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BACKGROUND AND INTRODUCTION

South Africa: 1.2 million km2, 750 000

km of roads; 120 000 km paved roads

South Africa’s road network is of a

high standard (from both regional and

international perspectives)

Slide # 3

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1. BACKGROUND AND INTRODUCTION

Slide # 4

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Slide # 5 Slide # 5

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Slide # 7 Slide # 7

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OBJECTIVES

9

Investigate the Performance-Based Standards approach to

heavy vehicles design and operations as researched and

implemented specifically in Australia, Canada and New

Zealand with a view to improving heavy vehicles operations in

South Africa:

• Reduced road wear (per tonne.km)

• Reduced vehicle trips i.e.

• Reduced congestion

• Reduced safety exposure risk

• Improved safety performance

• Improved transport productivity

• Reduced emissions (per tonne.km)

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10 SARF/IRF 2014 | 2-4 September, South Africa 10

THE ROAD TRANSPORT MANAGEMENT SYSTEM

• RTMS is a self-regulation initiative (management systems standard) which aims to address issues such as:

• Road infrastructure protection

• Heavy vehicle safety

• Logistics efficiency

• It achieves this by prescribing minimum standards for:

• Load management (over-loading/under-loading)

• Vehicle maintenance

• Driver training, health, hours

• etc.

• SABS standards: SANS 1395 Parts 1 to 3

• Similar to ISO 39001:2012 Road Traffic Safety Management Systems

• Ensures a level of professionalism in heavy vehicle transport

www.rtms-sa.org

http://www.rtms-sa.org/



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PERFORMANCE-BASED STANDARDS

• A PBS scheme for heavy vehicles has been successfully implemented in Australia as a voluntary alternative regulatory framework.

• This is currently the basis for the PBS/”Smart Trucks” demonstration project in SA.

• A set of safety-critical manoeuvres is prescribed, and vehicles must be tested/simulated performing each manoeuvre.

• Selected vehicle performance parameters are measured and compared with the minimum/maximum levels deemed safe.

• Each performance standard addresses a selected aspect of vehicle behaviour deemed critical to vehicle safety.

• RTMS is a non-negotiable pre-requisite for participation

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PERFORMANCE-BASED STANDARDS APPROACH

Prescriptive Standards Performance-Based Standards

What the vehicle looks like What the vehicle can do

Governs mass and dimensions Governs actual on-road performance

Constrains productivity Allows heavier and/or larger vehicles

Constrains innovation Promotes innovation

Prescriptive Standards Performance-Based Standards

Images courtesy of the Australian National Transport Commission

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3. PERFORMANCE-BASED STANDARDS

Manoeuvre/Test Performance Standard

Low-speed 90° turn (5 km/h)

Low-speed swept path

Tail swing

Frontal swing

Steer-tyre friction demand

High-speed lane-change (80 km/h) Rearward amplification

High-speed transient offtracking

Rollover Static rollover threshold

High-speed pulse steer (80 km/h) Yaw damping coefficient

High-speed on uneven road (90

km/h) Tracking ability on a straight path

Various (driveability standards)

Startability

Gradeability A

Gradeability B

Acceleration Capability

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3. PERFORMANCE-BASED STANDARDS

Pavement Vertical Loading Pavement Horizontal Loading Tyre Contact Pressure Distribution

Pavements Bridges

Infrastructure

Bridge Loading

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3. PERFORMANCE-BASED STANDARDS: ROLLOVER

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3. LOW-SPEED OFFTRACKING

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3. HIGH SPEED TRANSIENT OFFTRACKING

PBS Lane Change Manoeuvre (SAE J2179)

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3. HIGH SPEED TRANSIENT OFFTRACKING

baseline PBS

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3. ROAD WEAR ANALYSIS

• Based on SA Mechanistic-Empirical Design & Analysis

Methodology (SAMDM)

• Combines a stress-strain computational engine and

pavement engineering models (developed at CSIR)

• Design outputs include each pavement layer’s life and

stress/strain plots

• Layer life based on linear-log damage functions

(“transfer functions”) – derived from Heavy Vehicle

Simulator (APT) testing on pavement types since 1975

• “Load Equivalency Factors” are calculated for a vehicle

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3. ROAD WEAR ANALYSIS

50 AG*

150 G1*

150 C3*

150 C3

SUBGRADE

0.44

0.35

0.35

0.35

0.35

2000

250

2000

1500

90

1800

250

1700

120

90

1500

240

160

110

90

Pavement B:

ES100

50 AG*

150 G1*

150 C3*

150 C3

SUBGRADE

Poisson's

Ratio Phase I Phase II Phase III

Elastic Moduli (MPa)

0.44

0.35

0.35

0.35

0.35

2000

450

2000

1500

180

2000

450

2000

550

180

1500

350

500

250

180

Pavement A:

ES100

40 AG*

120 BC*

450 C3*

200 G7*

SUBGRADE

0.44

0.44

0.35

0.35

0.35

2500

3500

2200

300

150

2500

3500

1000

300

150

Pavement E:

ES30/ES50

S*

100 G4*

125 C4*

SUBGRADE

0.44

0.35

0.35

0.35

1000

200

1000

70

1000

180

120

70

Pavement D:

ES0.1

- - -

S*

100 G4*

125 C4*

SUBGRADE

0.44

0.35

0.35

0.35

1000

300

1000

140

1000

225

200

140

Pavement C:

ES0.1

- - -

30 AG*

150 C3*

300 C4*

SUBGRADE

0.44

0.35

0.35

0.35

2400

2000

1000

180

Pavement G:

ES10

- -

S*

80 BC*

150 C4*

SUBGRADE

0.44

0.44

0.35

0.35

2000

2000

1000

140

1600

1600

300

140

Pavement F:

ES1.0

- - -

S1*

100 C4*

100 C4*

SUBGRADE

0.44

0.35

0.35

0.35

2000

2000

1000

140

Pavement H:

ES0.3

- -

* Classification according to TRH 14 (CSRA, 1985)

8 Pavement Structures-1.ppt

Poisson's



Poisson's

Ratio Phase I Phase II


Poisson's



Poisson's


Elastic Moduli (MPa) Poisson's



Poisson's



Poisson's

Ratio Phase I

Elastic Moduli (MPa)Poisson's

Ratio Phase I


1600

1500

300

200

140

Phase III

2000

1800

300

140

-

Phase II

1600

250

100

100

-

Phase III

1000

1500

300

140

-

Phase II

200

100

100

100

-

Phase III

50 AG*

150 G1*

150 C3*

150 C3

SUBGRADE

0.44

0.35

0.35

0.35

0.35

2000

250

2000

1500

90

1800

250

1700

120

90

1500

240

160

110

90

Pavement B:

ES100

50 AG*

150 G1*

150 C3*

150 C3

SUBGRADE

Poisson's



0.44

0.35

0.35

0.35

0.35

2000

450

2000

1500

180

2000

450

2000

550

180

1500

350

500

250

180

Pavement A:

ES100

40 AG*

120 BC*

450 C3*

200 G7*

SUBGRADE

0.44

0.44

0.35

0.35

0.35

2500

3500

2200

300

150

2500

3500

1000

300

150

Pavement E:

ES30/ES50

S*

100 G4*

125 C4*

SUBGRADE

0.44

0.35

0.35

0.35

1000

200

1000

70

1000

180

120

70

Pavement D:

ES0.1

- - -

S*

100 G4*

125 C4*

SUBGRADE

0.44

0.35

0.35

0.35

1000

300

1000

140

1000

225

200

140

Pavement C:

ES0.1

- - -

30 AG*

150 C3*

300 C4*

SUBGRADE

0.44

0.35

0.35

0.35

2400

2000

1000

180

Pavement G:

ES10

- -

S*

80 BC*

150 C4*

SUBGRADE

0.44

0.44

0.35

0.35

2000

2000

1000

140

1600

1600

300

140

Pavement F:

ES1.0

- - -

S1*

100 C4*

100 C4*

SUBGRADE

0.44

0.35

0.35

0.35

2000

2000

1000

140

Pavement H:

ES0.3

- -

* Classification according to TRH 14 (CSRA, 1985)

8 Pavement Structures-1.ppt

Poisson's



Poisson's



Poisson's



Poisson's


Elastic Moduli (MPa) Poisson's



Poisson's



Poisson's

Ratio Phase I

Elastic Moduli (MPa)Poisson's

Ratio Phase I


1600

1500

300

200

140

Phase III

2000

1800

300

140

-

Phase II

1600

250

100

100

-

Phase III

1000

1500

300

140

-

Phase II

200

100

100

100

-

Phase III

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4. FORESTRY BASELINE AND PBS VEHICLES

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4. FORESTRY PBS VEHICLES (SMART TRUCKS

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4. MINING PBS ROAD TRAIN

• “BAB quad”

• 42 m

• 185 tonnes

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4. BI-ARTICULATED BUS

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5. EVALUATION OF RESULTS

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• 60 demonstration projects operational during 2013

• 130 car carriers plus 100 others in design phase

• 59 400 trips saved, 1.24 million litres of fuel, 3 250 tons of CO2

• Approx. 22% of pulp timber transported by Smart Trucks in 2013

• On average 14% fuel savings in forestry industry

2013

• Fuel savings: 1.24 million litres

• Emissions: 3 250 tons CO2

• Road freight in SA (2012): 303 billion ton.km

Assuming 10% are PBS vehicles would result in a reduction of 188 000 tons CO2 p.a.

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0.0000

0.0050

0.0100

0.0150

0.0200

0.0250

Fue

l Eff

icie

ncy

(Li

tre

s/to

n.k

m)

PBS Baseline

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5. EVALUATION OF RESULTS: Jan 2008 – May 2014

Crash rate ratio:

Smart Truck : Baseline 1 : 1.79

Timber Logistics Services

Unitrans Timber

Timber-nology

Buhle Betfu Timber24 Supergroup Gaskells Unitrans mining (RBM)

Totals

No of Crashes

Smart Trucks 17 15 5 3 3 8 1 0 52

Baseline 92 2 6 5 51 73 2 0 231

Total 109 17 11 8 54 81 3 0 283

Total Kilometres

Smart Trucks 11 262 165 2 426 555 3 571 410 1 857 239 1 224 438 1 338 743 1 037 815 829 819 29 575 000

Baseline 21 241 994 1 193 603 2 879 347 979 492 20 713 945 16 984 787 1 934 114 1 456 277 75 960 000

Total 32 504 159 3 620 158 6 450 757 2 836 731 21 938 383 18 323 530 2 971 929 2 286 096 90 931 743

Crashes per million kms

Smart Trucks 1.5 6.2 1.4 1.6 2.5 6.0 1.0 0.0 1.79

Baseline 4.3 1.7 2.1 5.1 2.5 4.3 1.0 0.0 3.21

Total 3.4 4.7 1.7 2.8 2.5 4.4 1.0 0.0 3.11

Caused by Third Parties and Pedestrians (included in figures above)

No of Crashes

Smart Trucks 11 3 3 0 0 5 22

Baseline 44 13 2 0 0 28 87

Total 55 16 5 0 0 33 109

% of Total

Smart Trucks 91.7% 33.3% 75.0% 0.0% 0.0% 62.5% 55.0%

Baseline 51.2% 650.0% 100.0% 0.0% 0.0% 39.4% 39.9%

Total 56.1% 145.5% 83.3% 0.0% 0.0% 41.8% 42.2%

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6. CONCLUSIONS

38

Potential benefits of a PBS approach to heavy

vehicle design and operations:

• Reduced road wear (per tonne.km)

• Reduced vehicle trips i.e.

• Reduced congestion

• Reduced safety exposure risk

• Improved safety performance

• Improved transport productivity

• Reduced emissions (per tonne.km)

Thank you for your attention [email protected]

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