Greenhouse Gas Emissions Mitigation in Road Construction...

The World Bank

Greenhouse Gas Emissions Mitigation in Road Construction and Rehabilitation A Toolkit for Developing Countries

Introduction to Greenhouse Gas Emissions in Road Construction and Rehabilitation Executive Summary

November 2010

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Introduction to Greenhouse Gas Emissions in Road Construction and Rehabilitation

Document Quality Information

General information

Author(s) Egis

Project name Greenhouse Gas Emissions Mitigation in Road Construction and Rehabilitation

Document name Introduction to Greenhouse Gas Emissions in Road Construction and Rehabilitation

Date November 2010

Reference

Addressees

Sent to: Name Organization Sent on (date):

Fei Deng The World Bank

Peng Wang The World Bank

Copy to: Name Organization Sent on (date):

Project Team Egis Bceom International

History of modifications

Version Date Written by Approved & signed by: 0 November 2010

Egis



Contents

Chapter 1 - Introduction ............................................................................... 8 1. Context and Background....................................................................... 8

1.1. Context...........................................................................................................8 1.2. Purpose of the Toolkit ....................................................................................8 1.3. Approach followed to develop the toolkit .......................................................8

2. Purpose of this Background report ...................................................... 9 3. Structure of this Background report .................................................... 9

Chapter 2 - General analysis of road construction emissions ............... 10 1. GHG emissions in road construction ................................................. 10

1.1. Road transport GHG emissions globally and by region ...............................10 1.2. Rationale for focusing on road construction activities..................................11

2. Main issues ........................................................................................... 11 2.1. Global emissions..........................................................................................11 2.2. Emissions per Item of work and per type of road ........................................12 2.3. Emissions per phase of work and per type of road......................................13

3. Current road construction practices in East Asia............................. 14

Chapter 3 - Development of a calculation tool ......................................... 17 1. Need for tools ....................................................................................... 17 2. Assessment of existing tools.............................................................. 18

2.1. Main principles of existing tools ...................................................................18 2.2. Comparison of calculations of existing tools ................................................19 2.3. Characteristics and limitations of existing tools ...........................................19

3. Functions of the proposed tool........................................................... 21 4. Assumptions, modeling and calibration ............................................ 23 5. Emissions factors................................................................................. 25

Chapter 4 - Alternative practices to reduce GHG emissions.................. 28 1. Identification of alternative practices ................................................. 28

1.1. Transport......................................................................................................29 1.2. Earthworks ...................................................................................................29

1.2.1. Rock excavation..............................................................................................29 1.2.2. Soil treatment..................................................................................................30

1.3. Pavement.....................................................................................................30 1.3.1. Pavement structure types ...............................................................................30 1.3.2. Investment and maintenance strategies .........................................................30 1.3.3. Overloading and impact of standards .............................................................32 1.3.4. Roughness......................................................................................................33

1.4. Structures.....................................................................................................33 1.5. Equipment / road furniture ...........................................................................33

2. Integration into the toolkit ................................................................... 34 3. Economic and financial analysis ........................................................ 34



Chapter 5 - Conclusions............................................................................. 36 1. Main outcomes ..................................................................................... 36 2. Challenges ahead ................................................................................. 36



List of Figures

Figure 1 Road transport emissions as part of global and transport GHG emissions.................. 10 Figure 2. Emission per item of work per type of road ................................................................. 12 Figure 3. Emission per GHG generator per type of road ............................................................ 13 Figure 4. Impact of technology on emissions: asphalt plant in poor condition compared to

a new one ............................................................................................................................. 15 Figure 5 Total CO

2 emissions over a 40 years period for a 1 km long and 13 m wide road

during construction, maintenance and operation (lighting, traffic lights, winter treatment). ............................................................................................................................ 17

Figure 6 Some of the tools reviewed .......................................................................................... 18 Figure 7. Simplified calculation process for materials................................................................. 19 Figure 7. CHANGER data input screen ...................................................................................... 20 Figure 8. Emissions from a ring road section in France - EGIS calculator ................................ 21 Figure 9. Breakdown of emissions from a ring road section in France - EGIS calculator........... 21 Figure 10. Proposed report format - ROADEO tool ................................................................... 22 Figure 11. Sample best practice data sheet – ROADEO tool..................................................... 23 Figure 12. Screenshot of the “upstream” data entry module of the ROADEO tool..................... 24 Figure 13. Screenshot of the materials emission factors – Changer tool ................................... 26 Figure 14 – Cumulated GHG emissions for construction and maintenance activities

depending on pavement construction / maintenance strategy ............................................. 31 Figure 15 – Comparison of distributed costs between initial construction and maintenance

activities depending on pavement construction / maintenance strategy .............................. 32



List of Tables

Table 1 – Regional breakdown of road transport share in transport GHG emissions ................ 10 Table 2 – Typical unit GHG emissions of various road categories (t CO2 eq. /km) ................... 11 Table 3 – Typical breakdown of GHG emissions by work items for various road

categories (t CO2 eq. /km).................................................................................................... 12 Table 4 – Typical breakdown of GHG emissions by generator for various road categories

(t CO2 eq. /km) ..................................................................................................................... 13 Table 5 – Orders of magnitude of GHG emissions related to the road construction

programme in 3 East Asian countries over 2009-2019. ....................................................... 16 Table 6 – List of parameters used for the summarized description of the road.......................... 24 Table 7 – List of case studies used to calibrate the model ......................................................... 25 Table 8 – Emission Intensities within VicRoads, CHANGER and EGIS calculators................... 26 Table 9 – Emission Intensities for steel according to various sources ....................................... 27 Table 10 – List of alternative practices included in the ROADEO tool........................................ 28 Table 11 – Relative importance of explosives in GHG emissions from earthworks

techniques ............................................................................................................................ 30 Table 12 – Comparison of GHG emissions from the construction of embankments,

bridges and tunnels .............................................................................................................. 33



Glossary of Abbreviations

AASHTO : American Association of State Highway and Transportation Officials AAU : Assigned Amount Unit ASTAE : Asia Sustainable and Alternative Energy Program BAU : Business As Usual CDM : Clean Development Mechanism CER : Certified Emission Reduction CRRAP : Cold Recycling of Reclaimed Asphalt Pavement DNA : Designated National Authority EASTE : East Asia and Pacific region EIRR : Economic Internal Rate of Return EPA : Environmental Protection Agency ERU : Emission Reduction Unit ESA : Equivalent Standard Axles ETS : Emission Trading Scheme EU : European Union FIRR : Financial Internal Rate of Return FUND : Framework for Uncertainty, Negotiation, and Distribution GHG : Green House Gas HMA : Hot Mix Asphalt HMAM : High Modulus Asphalt Material IPCC : International Panel on Climate Change IRR : Internal Rate of Return ITL : International Transaction Log JI : Joint Implementation NPV : Net Present Value ODA : Official Development Assistance ORN : Oversea Road Notes PDD : Project Design Document PPD : Perpetual Pavement Design PPM : Parts Per Million RGGI : Regional Greenhouse Gas Initiative SC : Stage Construction TRL : Transport Research Laboratory UNFCC : United Nations Framework Convention on Climate Change SCC : Social Cost of Carbon WMA : Warm Mix Asphalt


Executive Summary: Introduction to Greenhouse Gas Emissions in Road Construction and Rehabilitation

Chapter 1 - Introduction

1. Context and Background

1.1. Context The transport sector of the East Asia and Pacific region (EASTE) of the World Bank (the 'Bank') has the goal of identifying solutions to minimize greenhouse gas (GHG) emissions due to road construction and rehabilitation in the region. The transport team was awarded a grant from the Asia Sustainable and Alternative Energy Program (ASTAE) to finance creation of a toolkit addressing the GHG emissions resulting from transport development and restoration activities.

It is anticipated that over the next several years, developing countries in East Asia will be substantially expanding and restoring their extensive road networks. One result of these activities is increased GHG emissions. Reducing these emissions would significantly decrease the negative impacts related to these infrastructure works.

There are several steps involved in road construction, which contribute to the production and release of GHG emissions, beginning with site clearing, preparation of the sub-grade, production of construction materials (i.e. granular sub-base, base course, surfacing), site delivery, construction works, ongoing supervision, maintenance activities, etc. The aggregate GHG emissions for each project (phase, section, alignment) can be calculated depending on equipment, local condition, and standard construction and maintenance practice in a country.

This document has been prepared as part of a study aimed at identifying and quantifying the GHG emissions from current practices, and at developing a strategy for the better planning, design and construction of roads in order to give planners a tool where then can explicitly compare emissions and costs and therefore make more informed decisions – some of which will result in lower emission roads.

1.2. Purpose of the Toolkit The Greenhouse Gas Emission Mitigation Toolkit for Highway Construction and Rehabilitation (ROADEO), with the support of a user manual, will guide users through various stages and activities of road construction and rehabilitation, help them identify the sensitive areas to GHG emissions, and provide them with various mitigation options considering cost and benefit implications. With the Toolkit, decision makers, designers and technicians in the highway sector may easily compare various alternatives in construction, and optimize their practices to minimize GHG emissions and maximize energy efficiency. It is envisioned that this Toolkit could be used on both new and existing projects.

1.3. Approach followed to develop the toolkit The preparation of the Toolkit involved the following nine activities: Task 1: Undertake a broad assessment of GHG emission related to the transport sector Task 2: Complete a detailed literature review on GHG emissions from road construction and

rehabilitation activities



Task 3: Review of current road construction and rehabilitation practices in three East Asian developing countries

Task 4: Select recent case studies in each country with detailed analysis of GHG emissions Task 5: Perform GHG emission calculations Task 6: Identify gaps between best practices from developed countries and practices in pilot

developing countries and proposals for improving the situation Task 7: Assess costs and benefits of each alternative practice proposed in Task 6 Task 8: Develop the Greenhouse Gas Emission Mitigation Toolkit for Road Construction

and Rehabilitation Task 9: Complete the User Manual to accompany the Toolkit

2. Purpose of this Background report The purpose of this background report is to present the findings of the study that led to the development of the toolkit. It is intended to provide non-specialists with an introduction to main issues related to GHG emissions due to road construction in East Asia. While it was not possible to investigate all details, and to cover the very wide range of situations met on all road projects, efforts were made to identify orders of magnitude, extents, impacts, converging and diverging appreciations from the road community on some topics.

Thus, this report will hopefully provide detailed information gathered during the preparation of the toolkit, and make it available to users for their studies.

This document does not describe the functions of the ROADEO tool, which is the topic of the User Manual. Reference can be made to this document.

3. Structure of this Background report To make the document user friendly, it has been structured in several volumes. Each of these volumes covers an aspect of the GHG emissions. Volume 0 – Main body (this document): provides general information, and an executive

summary of the document’s content. Volume 1 – Introduction to GHG emissions from road construction Volume 2 – Review of current road construction practices in East Asia Volume 3 – Lower GHG emissions alternative practices for road construction Volume 4 – Economic and financial analysis of road construction GHG emissions



Chapter 2 - General analysis of road construction emissions

1. GHG emissions in road construction

1.1. Road transport GHG emissions globally and by region In 2005, transportation was the second largest source of energy related emissions or about 13.9% of total emissions. Road transportation accounts for about 90 to 95% of the transport sector’s contribution to GHG emissions.

Figure 1. Road transport emissions as part of global and transport GHG emissions

The information in the table below shows that road transport in Asia is a major contributor to transport GHG emissions. Asia is the region constructing the largest amount of new roads at the moment, and represented in 2005 37% of manmade GHG emissions.

Table 1 – Regional breakdown of road transport share in transport GHG emissions

Region Road transport contribution to transport sector

World 72% Asia 95 to 100%

Europe 93% North America 85%



Region Road transport contribution to transport sector

Central America and Caribbean n.a. Middle East and N. Africa n.a.

South Africa more than 50% Sub-saharan Africa n.a.

Oceania 84%

1.2. Rationale for focusing on road construction activities While road construction GHG emissions only represent 5-10% of total GHG emissions in the sector, they are growing rapidly, especially in Asia due to major ongoing road programs to support economic development.

The mitigation efforts are relatively easy to manage, and can have noticeable impacts (which is of interest to IFIs like the Bank) compared to actions on road traffic.

Moreover, most road agencies in Asia are not yet aware of the impact of their activities on GHG emissions, even though Asia is at the center of road construction actions. It is therefore important to raise the awareness of the stakeholders to improve current practices and to facilitate more informed decision making.

2. Main issues An assessment of GHG emissions of road construction was performed on “typical” road sections of various types or categories. In the absence of the order of magnitude of various issues, this was expected to provide an indication of: The respective importance of various parts of the road network on GHG emissions, through

a comparison of construction emissions of various categories of roads having different characteristics (geometry, pavement, structures) and ranging from expressways to unpaved rural roads.

The contributions of various components of the project, from pavement to structures, earthworks, road furniture, drainage

The calculations were made on simplified assumptions, and were performed with the “Changer” tool developed by the International Road Federation (IRF).

2.1. Global emissions The global GHG emissions for the construction of 1km section of each type of road are as follows:

Table 2 – Typical unit GHG emissions of various road categories (t CO2 eq. /km)

Expressway National Road

Provincial Road

Rural Road - Gravel

Rural Road - DBST

Emission (t CO2 eq. /km) 3234 794 207 90 103 Factor equivalent to Expressway 100 24.5 6.4 2.8 3.2



We can thus see that the construction of 1 km of expressway emits as many tons of CO2 as 4km of national roads, 15km of provincial roads, and about 33km of rural roads.

2.2. Emissions per Item of work and per type of road In the following table, the emissions produced by (i) the extraction/production of construction materials, (ii) their transport and (iii) the consumption of engines used for their laying have been gathered by items of works:

Table 3 – Typical breakdown of GHG emissions by work items for various road categories (t CO2 eq. /km)

Emissions (t C02 eq./km)

Expressway National Road Provincial Road

Rural Road - Gravel

Rural Road - DBST

Earthworks 161.40 15.89 12.00 2.74 2.68 Pavement 1333.86 424.66 157.30 72.20 85.53 Culverts 238.48 51.45 16.69 11.85 11.57

Structures 1067.99 119.39 20.57 3.03 2.95 Road Furniture 432.40 182.42 0.00 0.00 0.00

Total 3234.12 793.81 206.56 89.82 102.74

Figure 2. Emission per item of work per type of road



Structures and road furniture represent almost 50% (46,4%) of the emissions for the construction of an expressway. Choices regarding these items are thus of paramount importance to limit the GHG emissions of the project.

For national roads, the safety barriers represent alone one quarter of the global emissions during the construction. Changes in practices regarding these items (for instance wooden barriers would then have a very significant impact on the final footprint of the project.

For all the other roads, pavement is the major GHG producer, and the main parameters to be looked at are, as developed below, regards transportation emissions (distance to the concrete factory, distance to the quarry/borrow pit, etc.)

2.3. Emissions per phase of work and per type of road Table 4 – Typical breakdown of GHG emissions by generator for various road categories (t CO2 eq. /km)

Emissions (t C02 eq.) Transport emissions Material emissions Machines emissions Total Expressway 1003.71 2121.83 108.58 3234.12

National Road 235.00 522.62 36.19 793.81 Provincial Road 66.08 111.52 28.96 206.56

Rural Road - Gravel 19.83 55.51 14.48 89.82 Rural Road - DBST 25.91 62.35 14.48 102.74

Figure 3. Emission per GHG generator per type of road

For expressway and national roads, GHG emissions from the fabrication/extraction of construction materials represent the main GHG contributor, about 90% of the global emissions; it is less important for provincial and rural roads, about 80%.



Material transport is also a significant GHG producer, with around 25% for expressway and national roads and up to 20% for provincial and rural roads.

These two elements are hence the ones to be considered to improve significantly the GHG impact of a construction project.

3. Current road construction practices in East Asia Current design practices in the three case study countries have largely been influenced by western standards, mainly American Association of State Highway and Transportation Officials (AASHTO). The inadequacy of these standards with regard to local conditions, construction methods, equipment, maintenance strategies and overloading enforcement currently implemented in these countries often leads to premature fatigue and deterioration of road networks.

Project implementation practices are mainly characterized by the following aspects: Road projects are mainly funded from domestic sources in China, whereas ODA accounts

for about 25% in Indonesia and 40% in Vietnam. Private investment has been increasing in all three selected countries over the past years, enabling a change in packaging and contracting practices.

Construction markets are generally dominated by local contractors, with a significant share of state-owned companies, using substandard equipment and lacking capabilities in implementing the latest construction methods, except for China where major construction companies are using advanced practices. The involvement of foreign contractors, which could help promote technology transfer, has so far been limited to large projects where their contribution among consortiums has often not been significant. The use of Design and Build or EPC contractors is slowly developing, resulting in more efficient project implementation and management. Quality assurance approaches are, however, not yet widespread and need to be encouraged.

Procurement practices do not consider GHG emissions as a criterion for evaluation of bids. Similarly, environmental management policies, either governed by local regulations or by IFA guidelines, do not require GHG monitoring during construction.

Modern and old technologies coexist depending on the size and type of project.



Figure 4. Impact of technology on emissions: asphalt plant in poor condition compared to a new one

Key issues in construction practices for specific work components include the following: Earthworks are usually not optimized except for major projects (excessive height of

embankments to avoid grade separation and/or flooding, inappropriate definition of earth moving programs, use of small-sized equipment, limited use of soil stabilization)

Drainage systems are frequently under-designed or missing on minor roads, and deficiencies in the implementation and maintenance of structures often result in flooding and high maintenance requirements

Pavement: even on major projects, the life duration of flexible pavement happens to be shortened because of under-design (e.g. not taking into account overloading), inappropriate equipment (e.g. old mixing plants), deficiency of suitable materials (‘hard’ bitumen and aggregates) and lack of maintenance. Cement-concrete pavement has not been extensively used, and aggregate recycling is usually not implemented.

Structures: design and implementation practices for structures generally meet international standards. Improvements in the quality of locally manufactured cement-concrete is required to lengthen the duration life and more modern cement plants often translates into lower emissions per ton of cement produced.

Road furniture: metallic and concrete guiderails are commonly implemented on expressways and national highways, thus generating significant GHG emissions.

The analysis carried out on GHG emissions for typical road sections shows that the construction of expressways would generate far more GHG per kilometer than for other road categories. Pavement (only flexible pavement was considered in this analysis) would generally be the major GHG emissions source, but the share of GHG emissions from structures is quite significant for expressways, as is the share of metallic guiderails for national roads.

Applying this analysis to selected countries shows that possibilities for reducing GHG emissions may significantly vary depending on the current length, distribution of road networks by type and their assumed extension in the coming years.



Table 5 – Orders of magnitude of GHG emissions related to the road construction program in three East Asian countries over 2009-2019.

Indonesia Vietnam China CO2 emissions (t eq CO2) 2009-2019 2009-2019 2008-2020 2008-2020 2008-2020 2008-2020

Expressway 6,054,048 20% 13,696,941 54% 79,873,000 25% National Road 11,706,139 39% 5,848,337 23% 115,683,000 37%

Provincial Road 4,992,098 17% 2,208,218 9% 54,169,000 17% Rural Road –

paved 7,189,451 24% 3,708,669 15% 63,983,000 20%

Total 29,941,737 25,462,165 313,708,000



Chapter 3 - Development of a calculation tool

1. Need for tools Concern about climate change and greenhouse gas emissions have prompted action in most sectors and spurred the development of decision tools to help make choices transparent and illuminate their contribution to GHGs; transportation is no exception.

Early development of tools focused on the transportation activities themselves and sprung from much earlier studies and tools for energy efficiency and consumption. Given the smaller contribution to GHG emission from road construction and maintenance, it is only recently that studies have looked at these activities contribution and tools have just started to be developed.

The choice of materials and techniques for road construction and maintenance has a wide variety of impacts ranging from local pollution and environmental degradation to the contribution to greenhouse gases and climate change; Manufacturers and engineering companies have conducted studies on the GHG contribution of their material and alternate construction techniques. For example some studies have shown that concrete and cement are responsible for 50% to 160% times more emissions than asphalt. Recycling at the end of the life cycle may also provide substantial gains.

Figure 5. Total CO2

emissions over a 40 years period for a 1 km long and 13 m wide road during construction, maintenance and operation (lighting, traffic lights, winter treatment)



2. Assessment of existing tools To assess the existing situation, several emissions calculation tools have been assessed.

Figure 6. Some of the tools reviewed

Based on their suitability, the areas covered and their ease of use, the review focused on three tools in more detail: Changer calculator, from IRF Vicroads calculator Egis calculator, based on “Bilan Carbone” from Ademe

The assessment was done on three case studies selected in three pilot countries (China, Indonesia and Vietnam).

2.1. Main principles of existing tools All existing tools share the same principle; they combine: Materials, which are elaborated from basic materials having emissions factors through a

process which adds emissions. This includes by extension the clearing activities Transport (mostly of materials) at various stages of the construction process (supply of

plants, supply of site, on site) having emission factors Construction process having emission factors through the emissions of construction

equipment Others, to a lesser extent, such as personnel transport, management expenses, etc Therefore, all tools are simple calculation tools combining these generators, and adding up emissions from the various stages of the construction process and from various components of the works.



Figure 7. Simplified calculation process for materials

2.2. Comparison of calculations of existing tools The results of the comparisons made between various existing tools underline the following points:

Total GHG emissions from one kilometer road construction project (China and Indonesia case studies) range from 700 to 1,700 t-eq CO2. Total GHG emissions from one kilometer road maintenance / rehabilitation project (Vietnam case study) comprise between 300 to 500 t-eq CO2. This is consistent with the simplified calculation made on “typical roads”.

Depending on the calculator (and therefore data sources for emissions factors), total GHG emissions for a same case study can vary from a large range of value; the relative difference is consistent (around 15%) for Indonesia case study, it is more mixed for Vietnam (from 15% to 30%) and China case studies (from 0% to 30%). This is rather limited, especially when one considers that emission factors vary.

Materials embodied energy and transport activities represent the most important part of total GHG emissions, more than 80%; On-site impact represent less than 5%;

Regarding the calculators, GHG emissions evaluation performed with EGIS calculator appears in between the two others and GHG emissions evaluation performed with VicRoads (respectively CHANGER) appears as the greater (smaller) evaluation, except for the Vietnam case study evaluation.

2.3. Characteristics and limitations of existing tools The following has been observed:

Although interfaces vary from summary (excel based) to more sophisticated, the architectures of the assessed calculation tools are the same: emissions related to “on site” activities (construction equipment mostly), transport of materials and production of materials are assessed through the multiplication of quantities by unit emission factors.

The quantities used require detailed information on the project construction, such as the number of equipment of each type present on site, their production time. Detailed information is also required regarding the type of transport, and sometimes material composition (e.g., the quantities of aggregates and binder in concrete, so that transport



emissions can be calculated for aggregates from quarry to batching plant, and cement from cement plant to batching plant). This is very heavy and often not available at upstream stages, restricting the usage of the tool to informed specialists and to downstream stages.

Sometimes, the levels of details vary (diameter of trees cut, age of trees cut are requested while major approximations are made on other topics (overall fuel consumption)

Figure 8. CHANGER data input screen

The quality of reports provided by tools varies. However, and in general: the breakdowns of emissions are not given according to types of works, which makes the use of results difficult: one cannot know, on which aspects of construction to focus to reduce emissions. The use of results is not easy in the absence of exporting of results in practical editable soft format.

The emissions factors vary from one tool to the other. This does not create major problems; as long as the user can modify these factors to suit the specific conditions of the project. In some cases though (Changer) this is not possible. It is even difficult to extract the emissions factors used for a calculation (going through screen captures).

The ease with which new materials, transport modes or vehicles, or construction equipment can be added is generally easy. This operation is sometimes impossible. This may prevent users from comparing alternative construction methods as would be presented by contractors during implementation (materials alternatives for example).

The coverage of construction activities is not always very clear and complete. Earthworks, road furniture, structures or others are difficult to take into account. Transport is simplified, and sometimes limited to road transport while water and rail may play a significant role.

The figures below show sample graphic outputs from Vicroads and Egis (Changer does not provide such outputs). The information provided cannot be directly used for example:



In the Vicroads tool, if there are concrete barriers, their contribution cannot be identified).

In the Egis tool, the contributions of various concrete components are not identified, and there might be pavement and structural concrete.

Figure 9. Emissions from a ring road section in France - EGIS calculator

Figure 10. Breakdown of emissions from a ring road section in France - EGIS calculator

3. Functions of the proposed tool The above reasons led to the proposal to develop a tool, with the following principles:

The tool should be open and transparent, allowing:



a. Addition of new equipment, new materials, and new transport modes

b. Easy access to and modification of GHG generator characteristics, including emission factors. Thus, the addition of an expandable emission factors database was considered to be crucial

The tool should be easy to use even at upstream stage, assisting users (including non-engineers) to assess the quantities of GHG generators from project macro-quantities. This involved the development of a model

The tool should be useful to planners and designers. It might be used at downstream stage for assessing / comparing bids or construction method statements.

The reporting should be useful to the decision making (engineering, planning) process to optimize the project; therefore, the tool should identify impacts of decisions

Figure 11. Proposed report format - ROADEO tool

The tool should be used to identify, propose, and assess the impact of alternative construction or management practices



Figure 12. Sample best practice data sheet – ROADEO tool

4. Assumptions, modeling and calibration For the cases when the user, at the upstream stage, does not have the required details to perform the emissions calculation, a model has been designed in 2 stages:

A first stage calculates quantities of items of road works, based on general characteristics of the project. The output of this stage is a “bill of quantities” at feasibility study stage and the work items are broken down into “work series” reflecting the types of works.

A second stage calculates the quantities of generators of GHG emissions based on the quantities of items of road works and on general characteristics of the project. These generators have been broken down into materials, transport, equipment and others.



Figure 13. Screenshot of the “upstream” data entry module of the ROADEO tool

The following table summarizes the 26 model parameters (17 for stage 1, 9 for stage 2) to be defined by the user.

Table 6 – List of parameters used for the summarized description of the road

Parameter description unit Stage %ECD: length of existing cross drainage as a percentage of requirement % 1 %ELD: length of existing longitudinal drainage as a percentage of length of road % 1 %EWB: parameter reflecting the balance between cut and fill % 1 %GLP: general longitudinal profile % 1 %MNT: length of road in mountainous terrain as a percentage of road length % 1 %RCK: volume of rocky soil as a percentage of volume of soil % 1 %URB: length of the road project crossing urban areas as a percentage of road length % 1 %WDB: number of bridges to be widened as a percentage of number of bridges % 1 CBR: California Bearing Ratio % 2 EAL: Equivalent standard axle (8.2t) loading – ESAL 2 ECS: Existing cross section m 1 L: road project length m 1 LW: lane width m 1 MW: median width m 1 NBL: number of lanes u 1 OST: Overlay structure type list 2 PST pavement structure type 2 RTP: Road type list 1 STH: Area where subgrade has to be treated with hydraulic binders % 2 SW: shoulder width m 1 TBM: Type of barrier material list 2 TSB: type of structure (standard bridges) list 2 TSM: type of structure (major bridges) list 2 TSW: Type of structure (wall) list 2 TUN: length of tunnel (not used pending further development) m 1 WTP works type list 1



This model is highly simplified, is not based on engineering but rather on empirical data, and does not intend to reflect real project values. Its intent is to provide rough estimates of tentative nature for projects at a very initial stage. The model has been used on several projects to check its accuracy, as shown in the table below.

Table 7 – List of case studies used to calibrate the model

Project Country Type Comment

EINRIP Indonesia National roads Rehabilitation

Including bridges

PRIP Cambodia Rural roads Rehabilitation

NPP Vietnam National road Rehabilitation

Asphalt overlay No bridge

STDP Sri Lanka Expressway New alignment

RPPF Sri Lanka Provincial roads Widening

TIIP Sri Lanka National road Widening Surface treatment

Rui-Gan Expressway China Expressway

New alignment

While there are significant differences between the model and the project bill of quantities, the model has shown the capability to approach real quantities with an accuracy of less than 40% item by item, and with an overall accuracy that can be considered reasonable at upstream stages. It must be noted that the impact of these differences on GHG emissions remain to be assessed.

5. Emissions factors Significant issues regarding emissions factors include: The various units used by tools (tons, cubic meters, etc.). This is not user friendly and could

be the source of errors as different densities are used to convert volumes into weights. The various compositions used for composite materials. This is shown in the screenshot of

Changer below. The assumptions made on some materials. This is mostly the case with cement as shown

below.



Figure 14. Screenshot of the materials emission factors – Changer tool

Table 8 – Emission Intensities within VicRoads, CHANGER and EGIS calculators



The emissions factors having a high impact and varying significantly include: Cement Steel Electricity

They are partly related as slag can be used in cement concrete, while electricity is the source of energy for recycled steel used for steel bars.

For example, and in order to evaluate the impact of the uncertainty of steel emission factors, a specific study has been done on steel emissions based on the following ratios:

Table 9 – Emission Intensities for steel according to various sources Source Year kg CO2/ kg steel

ADEME 2006 3190 US EPA 1998 4162 US EPA 2002 4081 US EPA 2006 4081 OFEFP 1998 3241

AEA Technologie 2001 2970 MIES 1999 - 2003 1599

SETRA 2009 1027 - 1503

This should be the subject of further research. Current indications are that the range reported by SETRA is the most accurate.

Electricity is related to power production (coal, petrol, gas, hydraulic, nuclear), which is highly influenced by the region and even countries or plants. It is subject to variations in the medium term as a consequence of power production strategies.

Users shall exert great care in selecting values or confirming default values that will be proposed by the tool.



Chapter 4 - Alternative practices to reduce GHG emissions

1. Identification of alternative practices The following provides indications on orders of magnitude of potential impacts of alternative practices on various components of roadworks.

The list of proposed alternative practices is shown in the table below:

Table 10 – List of alternative practices included in the ROADEO tool

Area Code Alternative practice Parameters / Triggers Work components & GHG generators concerned

EAW 002 Use labor intensive

techniques for excavation

OR(RTP=provincial road ; RTP=rural road)

Earthworks (Transport, Equipment)

EQU 001 Optimize location of road safety barriers

GHG emissions from barriers > 5% of total

emissions

Equipment/furniture (Materials, Transport,

Equipment)

EQU 002 Optimize street lighting %URB>0 Equipment/furniture

(Materials, Transport, Equipment)

GEN 001 Optimize procurement & contracts All General

GEN 002 Optimize transport All All

GEN 003 Implement adapted geometrical standards All

Structures, Pavement, Earthworks (Materials, Transport, Equipment)

GEN 005 Organize workzone traffic management

WTP = rehabilitation or WTP = widening General

PAV 001 Manage overloading All Pavement (Materials, Transport, Equipment)

PAV 002 Use high modulus asphalt concrete

PST = bituminous pavement on granular

materials OR PST = bituminous materials on hydraulic

bound materials OR PST = bituminous

pavement on bituminous bound materials

Pavement (Materials, Transport)

PAV 003 Use warm and half warm asphalt mixes

OR(RTP = provincial road ; RTP = rural road)

Pavement (Materials, Transport)

PAV 005 Use recycling OR(WTP =

rehabilitation ;WTP = widening)

Pavement (Materials, Transport, Equipment)

PAV 008

Consider gravel roads and surface treatment instead of bituminous /

cement concrete pavements

RTP = rural road EAL < 4




Area Code Alternative practice Parameters / Triggers Work components & GHG generators concerned

PAV 009 Ensure low roughness all Pavement (Materials, Transport, Equipment)

PAV 010 Soil stabilization

DCF > 3 DQA > 40 DQB > 40

CBR<7


PAV 012 Take maintenance into account during design EAL>5 Pavement (Materials,

Transport)

STR 001 Make optimal use of materials (SBA + IBA + MBA)>0) Structures (Materials,

Transport, Equipment)

STR 002 Use fly ash in concrete

STR 004 Ensure recycling of steel

GHG emissions from metal > 10% of total

emissions

Structures (Materials, Transport)

STR 006 Optimise alignment to Minimise structures

MBA>0 SBA>0

Structures, Pavement, Earthworks (Materials, Transport, Equipment)

More alternative practices have been identified, but some of them could not be documented in a sufficient manner. It is hoped that future developments will allow to better describe such practices and to improve the ROADEO tool. Meanwhile, such other alternative practices are described in the corresponding volume of this background report.

The sections below provide a summary description of the main findings on alternative practices.

1.1. Transport Transport of materials represents about 30% of the GHG emissions of a road project.

From that, about 50% are related to local transport (less than 25 km).

Reduction of emissions can be the result of the following actions: Use of more efficient road vehicle fleets having a lower unit emission ratio. This can be

significant as the efficiency improves with the use of trucks with higher payload (50% decrease in unit emission and savings of more than 20% in total transport emissions).

Modal shift from road to more efficient modes (rail or water having unit emissions 17 times lower) over long distances. Further improvement can be up to 8% of the total emissions after road transport has been optimized

1.2. Earthworks

1.2.1. Rock excavation Excavation in hard soil generates two to three times more GHG than in ordinary soil. The use of drilling rigs rather than light drillers is twice as productive, but produces 35%

more GHG per cubic meter of rock excavated. Productivity of labor intensive methods is 250 times lower, while involving three times more

labor. If labor emissions are considered to be neutral, this is a significant reduction in emissions.

Explosives represent only five to seven percent of the emissions of the excavation process.



The use of explosives for excavation seems to produce less GHG as shown in the table below:

Table 11 – Relative importance of explosives in GHG emissions from earthworks techniques

Excavation method Output (m3/day)

Fuel Consumption (l)

Explosives (kg)

GHG (kg CO2eq)

GHG (kg CO2eq/m3)

Hammer 1,000 864 2,160 2.2 Mining (light driller) 1,250 480 500 1,469 1.2 Mining (drilling rig) 2,500 1,725 1,000 4,851 1.9

Excavation and loading / transport to fill are of the same order of magnitude at around 2 kg

CO2eq/m3 of excavated rock. Interestingly, and in spite of the health and safety aspects, which are less satisfactory than

with other methods, the local lightly mechanized technique is the most efficient in terms of GHG emissions.

1.2.2. Soil treatment

Except in cases where materials are not available locally (within less than approximately 150 km), soil treatment is not very effective in terms of GHG emissions, due to the emissions of lime, and to its transport.

It should be noted that studies are underway to assess interest of soil treatment in terms of sustainable development with respect to other indicators than GHG emissions.

1.3. Pavement A number of alternative techniques have been identified and their potential impact assessed, base on the use of different materials (recycled, high modulus asphalt), design (bituminous / concrete structures, investment schedule) or construction technique (warm / half warm asphalt)

1.3.1. Pavement structure types According to literature and based on an objective review of the corresponding results taking

into account the maintenance cycle, sstructures based on cement concrete have higher emissions, structures based on bituminous concrete have lower emissions , and composite structures have intermediate emissions. There is a factor from 1.6 to 3 between the higher emissions factors (thick cement concrete layers) and the lower (bituminous structures).

Structurally optimized pavement structures (high performance bituminous mixtures, Continuously Reinforced Concrete Pavements on bituminous base which according to recent studies makes the most optimal use of materials for cement concrete pavement structures) have lower emissions than the non optimized pavement structures

Orders of magnitude for the construction, maintenance and end of life of pavement structures range from 65 to 175 kg/m².

Cold mixtures as well as recycling technologies and materials have lower emissions (a factor of three when compared to hot mixture bituminous structures).

1.3.2. Investment and maintenance strategies Maintenance represents 20 to 40% of the overall emissions of pavement over 30 years

indicating that tradeoffs exist between construction and maintenance with regard to both cost and emissions.



For the given life duration, taking into account the life cycle and standard maintenance scenarios for both structure types, cement concrete structures are in general twice as much GHG emitting as composite structures, while bituminous structures have the lowest GHG emissions.

The relationship between maintenance and traffic depends on the investment strategy (initial construction / maintenance). Maintenance strategies and catalogue biased towards increased initial investment and the above studies may not fully reflect the whole range of situations.

Figure 15 . Cumulated GHG emissions for construction and maintenance activities depending on pavement construction / maintenance strategy



Figure 16. Comparison of distributed costs between initial construction and maintenance activities

depending on pavement construction / maintenance strategy

Staged construction seems to lead to significantly higher total emissions and the perpetual

pavement strategy seems to lead to slightly lower emissions than standard pavement structure after 40 years

It should however be noted that the damage factor after 40 years is significantly lower (i.e. better structural condition of the asset) in the case of perpetual pavement

Impact of maintenance operations on traffic has not been taken into account, which may significantly impact the results for a T7 traffic class in TRL ORN31.

The above results do not take into account any discount rate.

1.3.3. Overloading and impact of standards Significant discrepancies in GHG emissions can result from the use of different pavement design standards (between 0 and 17% depending on traffic loads considered for this specific case study, or even up to 45% in the latter comparison). For example Vietnamese standards are based on empirical methods attempting to model pavement structures as two-layer or three-layer equivalent. Alternative standards are based on combining semi-empirical (AASHTO 1193, TRL ORN 31) and analytical methods (AASHTO 2004, Austroads), which take into account the fatigue performances of road materials. The impact of overloading on thickness of pavement structures and on corresponding GHG emissions is significant and has been assessed between 23 and 49% of pavement emissions depending on standards considered.



1.3.4. Roughness

For a given speed, the maximum range in consumption for different surface textures appears to be about 2 Liter/100 km. Limiting rolling resistance due to pavement texture could lead to significant savings in GHG emissions on the long term (i.e. over the life-cycle of a given road section), although road safety requirements have to be concurrently considered.

The impacts of pavement roughness on GHG emissions are deemed much more significant than those of texture. Improvements in pavement roughness, especially by reducing short-wavelength unevenness, could decrease fuel consumption by up to four liters/100 km as assessed using a mathematical “suspension model”.

Actions to ensure low roughness (such as proper construction techniques) are therefore important, although their impacts are difficult to estimate in advance.

1.4. Structures The construction of bridges involves the emission of about three tons of CO2 eq / m² of

bridge deck. The structure’s material has an impact, however, for a given structural type, this impact is

typically less than 15% The structural type has a higher impact, for a given material. The table below summarizes

this impact; the more complicated the structure type, the higher the relative emission: Steel is a major component of structures. Uncertainty on its emission factor, which relates to

its origin and the technology used to produce it (i.e., if it is recycled or not, the origin of electricity, etc.), can have an impact of up to 30% for structure types making extensive use of it (steel, composite)

Emissions due to maintenance could be considered as of the same magnitude as emissions during construction.

The relative emissions of “typical” roads on an embankment, a viaduct and in a tunnel are summarized in the table below:

Table 12 – Comparison of GHG emissions from the construction of embankments, bridges and tunnels

GHG emissions

from construction

Embankment (tCO2eq/km)

Bridge (tCO2eq/km)

Bridge / embankmen

t

Tunnel (tCO2eq/km) @420tCO2eq/(m²xkm)

Tunnel / embankmen

t

Expressway 2,971 74,397 25 75,547 25 National Highway 739 35,649 48 37,773 51

Provincial Road 191 27,899 146 30,219 158

Rural Road 100 20,127 201 23,608 236

1.5. Equipment / road furniture Over a life cycle, the relative importance of emissions due to barriers ranges

• from four to 23% of GHG emissions due to pavement in the case of steel or concrete barriers

• from two to 12% in the case of wood barriers



There may be a significant interest in limiting the use of steel and concrete barriers where possible through adequate and safe design (safety zone cleared of obstacles, removal of aggressive spots, etc.), or to replace it by wood barriers when traffic volumes and loads are low enough. The potential impact could be up to 50% of the length of barriers, or from 2 to 12% of the emissions of pavement. This requires anticipation in the geometric design, and efforts during the design phase.

Lighting brings significant contribution, even more so when operation is taken into account.

2. Integration into the toolkit The identified alternative practices have been included in the tool. For some of them, their relevance to a particular situation can be summarily assessed through the values of parameters (e.g. high traffic, presence/absence of materials, relative importance of emissions due to a part of the works, etc.).

Datasheets describing the main issues, potential impacts and reference materials ( such as sources) can be activated to provide the user a first level of guidance to optimize the project. Additional guidance may be found in the technical volumes of this background report.

Again, this toolkit shall not replace a sound engineering study, which is almost systematically required to design the alternative practice. However, the toolkit is providing the information to the users, for them to assess where major possibilities of optimization lie, and the extent of such optimization. It also provides guidance on the engineering efforts to be deployed to achieve these optimizations.

3. Economic and financial analysis According to the current level of carbon market price, the level of the discount rates to be adopted for financial analysis, but also considering the conditionality to be met for benefiting from carbon credits likely to be generated through the CDM, carbon pricing can probably not be considered as a realistic incentive for developing the GHG friendly alternative practices that have been identified in the Task 6 – report for road construction, rehabilitation and maintenance. Indeed, considering the potential revenues of carbon credits likely to be generated by emission reductions has very limited impact on the financial viability of the practices that have been analyzed. Accordingly, projects aimed at developing such practices would most probably not meet the additionality criterion of the CDM and would not be eligible to benefit from carbon credit. It has been checked that a dramatic increase of the carbon market price from 15 US $/t to 100 US $/t or changes in other parameters (market price growth rate, discount rate, etc.) would not substantially change these conclusions. One of the reasons of these results is the limitation of the duration of the evaluation period to 21 years maximum, which is the maximum duration of the crediting period during which a GHG friendly project promoters can benefit from carbon credits generated by their emission reductions. On the contrary, considering the economic benefits from GHG emission reductions significantly enhance the economic return of project aimed at developing the GHG friendly alternative practices that have been identified.



This is particularly true for alternative practices impacting life-duration of the road and/or maintenance operations: the present value of economic benefits from GHG emission reductions, including those occurring in the long-term, are significant and reach about 10% or even more of the total net benefits generated by applying such alternative practices; nevertheless, most alternative practices studied in the present report are “intrinsically” economically viable and there is no case where a GHG friendly alternative practice is not economically viable without considering benefits from GHG emission reductions and becomes viable when such benefits are considered. One of the main reasons of the significant positive impact of the economic benefits from GHG emission reductions on the economic return is that the much longer duration of the evaluation period adopted for the economic analysis, together with the low discount rate, allows taking account of the very long term intergenerational benefits from GHG emission reductions



Chapter 5 - Conclusions

1. Main outcomes The main contributions of the study under which this background report has been prepared can be summarized as follows: Progress in understanding the main contributions to GHG emissions from road construction

activities. This has been done for various types of projects (covering a broad scope from access controlled divided carriageways roads to unpaved rural roads) and various work components (earthworks, pavement, drainage, structures, road furniture, etc.)

Development of an open, transparent, flexible emissions calculation tool that can be used at any stage of a project and provide information for decision making. Inputs can be entered at planning level (17 parameters to describe the road); at design level (based on a bill of quantities) or at implementation (as other available tools do, using quantities of materials, detailed description of logistics and construction equipment used). This involves a model, which is being calibrated based on data collection from several projects in Asia.

This tool is a major improvement for road planners and designers, and brings functionalities that did not exist before.

Identification and documentation of alternative practices to reduce GHG emissions from construction activities. While the identified actions cover all work items, as well as institutional or planning issues, it can be expected that other will be identified and can be integrated in updates of the toolkit. The calculation tool includes these actions and assists the user in selecting applicable alternatives to reduce GHG emissions.

Carbon finance has been explored, as a support to the implementation of such alternatives. It has been found that financial benefits resulting from such implementation are far lower than potential costs savings due to such actions. Market price of carbon should be more than 10 times higher for such mechanism to have an interest (except for optimization of materials transport). However, economic analysis based on the social cost of carbon and on a longer assessment period, indicates a higher interest for implementing alternative practices.

2. Challenges ahead While progress has been made, significant challenges remain ahead, including: The absence of a unified source of information in East Asian countries (and in general) on

GHG emissions. The uncertainty (or lack of general agreement) on the values of emissions of some major

contributors to road activities emissions (cement, steel, etc.), in relationship with the life cycle assessment. This is partly due to the lack of clarity regarding the role of byproducts, and of the end of life treatment (including recycling)

The variation of GHG generators during the life cycle, and the difficulty for road planners and designers to assess them. GHG emissions highly vary depending on the precise location of materials sources (quarries, soil treatment, as well as the origin of cement, bitumen, and steel), on the choice of construction technology (such as the type of asphalt mixing plant), or even on the construction schedule (such as the need to work during rainy



season). The comparison of orders of magnitude between the variations due to the above factors, and the gains due to optimizations, makes it difficult to define an optimized design at early stages.

All stakeholders (road agencies, consultants, contractors, concessionaires) need to become aware that their actions at all stages of a project can contribute to reducing the CO2 burden.

Establishment of a users’ community, and improvement of the toolkit based on experience gained while using it and on the feedback of users. Initially, it is envisioned that the tool will be used to assess road projects’ impact and optimize the most significant practices.

Greenhouse Gas Emissions Mitigation in Road Construction...

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