2.1 Green Highway and Sustainability
Green highway can be
defined as highway that is design and constructed with the integration of
highway functionality and environmental requirements. Ecological requirements
are considered throughout the overall process in highway development either in
planning, design, construction, operation, or maintenance.
As part of major elements
in the sustainability development, green highway focuses on three major sustainability
development aspects which are economic, social and environment. In the economic
aspect, the primary idea of sustainable development is to increase the
profitability through the effectiveness of the resources utilization, and at
the same time improving the quality of life in the social aspect without
compromising the environmental aspects. The growing concern on the impact of
the utilization of construction materials such as natural resources and non –
renewable materials depletion besides the increasing of the material production
cost have boosted the interest of the researcher to study and find the
alternative of the conventional highway construction materials (Balubaid et
According to AASHTO,
transportation is one of the largest contributor to the environmental impacts,
especially harmful CO2 emissions that would results global warming. It is
identified that transportation consumes 22 percent of the global energy, burns
about 25 percent of fossil fuel, and release 30 percent of air pollution and
greenhouse gasses. These factors contribute to the growing concerns of
depletion of natural and non-renewable resources, global climate changing,
disruption of ecosystems, and toxic pollution. The greenhouse gas (GHG)
emissions from constructing and rehabilitating highway infrastructure make up
13.22% of the construction sector.
al. (2014) stated
that the negative environmental impacts of the highway development such as noise,
ground and water pollution, habitat disturbance, land utilization, air quality,
climate change and contamination to plant and wildlife can be reduced by the
sustainability approach. Therefore, it is important for the highway stakeholders
to apply the sustainability concept in the highway development project and this
application should be evaluated by the green highway rating assessment tools.
Green Highway Index (MyGHI)
As compared to the green
initiatives on the building construction development , green highway is considered
in the early stage in term of the implementation in Malaysia (Balubaid et
al.2015). A green highway assessment
tool is developed with the aim of providing an evaluation guidelines for green
practices in highway development which highlights the environmental and
economic aspect. Rosli et al. (2014) defined highway assessment tool system as
a rating tool for sustainable guideline, which include the overall process in
highway developments either in planning, design, construction, operation, or
The green highway
assessment tool is developed specifically for the Malaysia’s tropical weather,
environment, cultural and social needs in order to measure the classification
of highway, according to its criteria, sub criteria and elements for
sustainable purpose. In order to achieve a sustainable highway; the overall
process of highway development and assessment should be integrated with the
local ecological protection consideration. This integration will help in
avoiding any further environmental degradation and uncontrollable resource
consumption. In Malaysia, the Malaysian Highway Authority or “Lembaga Lebuhraya
Malaysia (LLM)” was authorized to supervise and execute the design,
construction, regulation, operation and maintenance of inter-urban highways, to
impose and collect tolls, to enter into contracts and to provide for matters
connected therewith. The development of green highway assessment tools is
parallel with the vision of LLM which to become a world class in highway
development, management and regulatory affairs. LLM may enhance employees and
concessionaire awareness, skills and expertise through the launching of the
assessment (Balubaid et al., 2015).
to Institute for Smart Infrastructure and Innovative Construction (ISIIC),
Malaysia Green Highway Index (MyGHI) manual is designed as a performance
baseline standard in order to measure the level of greenness for current
highways in Malaysia. This manual explains several fundamental elements of
green highway development that are suitable for the Malaysia condition. As a
result many parties in the highway industry will obtain the benefits of
developing sustainable green roads, pathways, and expressways.
2.2.1 MyGHI Scorecard
According to ISIIC, MyGHI assessment comprises
of five (5) main elements which are Energy Efficiency (EE), Environmental and
Water Management (EWM), Material and Technology (MT), Sustainable Design and
Construction Activities (SDCA) and Social and Safety (SS) which covers the
overall process in highway developments in planning, designing, construction,
operation, or maintenance of highways in Malaysia. Table 2.2 shows the
criteria of each elements to be audited under MyGHI assessment.
in Green Technology and Materials
In order to minimize the
greenhouse effect caused by carbon emission, green technology is identified as
one of the effective solutions that should be implemented by the highway
stakeholders. Green technology is part of the sustainable development which applies
the knowledge of environmental science in conserving the natural resource and at
the same time it can sustain the need for the present and future generations (Balubaid et al., 2015).
Technology in Pavement
According to Bin (2013), pavement
is one of the major component of highway systems, and also fundamental to
economic accomplishment and personal mobility. Despite large amount of
investment to be devoted in this component, highway stakeholders seem to have unclear
acceptance and understanding about the environmental impacts of the
conventional pavement systems due to various reasons.
Leif Wathne of the American
Concrete Pavement Association (ACPA) at the American Society of Civil Engineers
(ASCE) and Transportation and Development Institute (TD) first Green
Streets and Highways Conference (GSHC), hosted in 2010, mentioned that many highway
stakeholders are solely focusing on the construction process and the materials
in their decision making, and miss to consider on green technology of pavement,
even though the pavement’s life cycle can give an enormous impact on its
Rosli et al. (2014) stated
that material and pavement technology is one of the criteria that need to be
addressed critically because any highway project will consume a lot of
resources and implements several methodologies in their development plans.
Material and pavement technology elements should be given high priority by the
stakeholders in highway development.
of Industrial By-product
Vasudevan et al. (2012)
mentioned that the utilization of waste industrial by product such as fly ash,
steel slag, rubber, glass, etc. can reduce energy consumption in transportation
and minimize the hazardous gas emission such as greenhouse gas and CO2. The
usage of industrial by product also would improve the performance of plastic
tar road conclusively besides the road is good for heavy traffic due to better
binding. The utilization of these by products in the pavement construction will
increased the strength and produce a better surface condition for a prolonged
period of exposure to various climatic changes.
Kasturirangan et al. (2010)
stated that the rubblized Portland Cement Concrete (PCC) layer used in pavement
of green highway produce higher strength as compared to the strength of virgin
PCC layer and has better performance under that structural condition.
Romier et al. (2006) stated
that the cool pavement technology is always related to the term ‘albedo’.
‘Albedo’ is defined as solar reflectance, where the higher albedo indicates
high reflectance of sunlight energy by the pavement and vice versa. The
tendency of high reflection of sunlight on the highway that apply the cool
pavement technology will reduce the ambient air temperature thus this will
avoid the heat island effect.
The implementation of warm
mix asphalt technique allows the production temperatures to be 10°C to 37.8°C
lower than the conventional hot mix asphalt (HMA) production temperatures. This
can save burner fuel up to 35% (Brown, 2008).
Rosli et al. (2014) stated
that the most relevant and recommended green elements to be applied in green
highway development are recycled materials and local materials. Eisenmen (2012)
stated that the selection of recycled content materials for the pavement mix
can give positive impact on the highway project in many ways. Recycling can
help construction-related waste from going straight to a landfill, and can help
in the reduction of natural resources utilization that come from the renewable
and non-renewable resources.
Widayat (2008) highlighted
that in order to be acceptable, recycled materials have to provide the overall
better aspect such as providing the similar performance to conventional
materials as well as reducing the cost. Where existing pavements have performed
satisfactorily it is likely that the original aggregates will comply with the standard
requirements although some degradation can be expected on reclamation.
Recycling in highway development
may come from the recycling of the existing pavement materials. It does not
limited to the utilization of the recycled content of the highway construction materials
only. Recycling existing pavement materials during rehabilitation and
reconstruction of roads provides a more sustainable alternative compared to
conventional methods such as full removal and replacement of the pavement
materials (Ebrahimi et al., 2012). Lee et al. (2010) mentioned that the in situ
recycling of roadway materials is actually a cost effective and environmentally
friendly, resulting in reduced energy consumption, greenhouse gas emissions and
waste material disposal.
The usage of Reclaimed
Asphalt Pavement (RAP) and Recycled Concrete Material (RCM) in order to produce
new pavement can minimize the dumping wastes of asphalt pavement and concrete
materials in the landfill, reduce the consumption of virgin materials, and
protecting the environment either using hot in-Place Recycling (HIPR) or Cold
in-Place recycling (CIPR) methods. By practicing these recycling techniques,
there is no excess material to haul and at the same time might reduce the fuel
and transportation costs (Kasthurirangan, et al., 2010).
2.3.5 Economical and Cost Effective
Santero et al. (2011)
mentioned that long life pavement eventually can reduce the maintenance cost
and life cycle cost and may reduce the rehabilitation process of pavement. The
application of elements in green materials and pavement technology will effectually
decrease gas emissions and harmful substance, which results the better economic,
society, and environmental aspects.
Einsmen (2012) stated that
the recycled content may be less costly than purchasing new content. He also
added that the utilization of the materials that come from the waste generated
at the construction site or from local facility may reduce the costs of
material transport to the project site. Bennet and James (1999) also mentioned
that the higher the materials recycling rate, the more effective the economic
feasible can be obtained from the recycling or reuse activities.
Kasturirangan et al.,
(2010) giving the advantages of using reclaimed asphalt pavement and recycled
concrete material in the pavement construction will produce zero excess
material to haul and this will simultaneously minimize the fuel and
Bin (2013) mentioned that under
the conventional pavement development, the design period of pavements is
limited to 20-year or less, even though many existing pavements still function
over the design life under timely maintenances. Driven by the design, material,
and construction technology developments, it is a natural idea to consider
extending the pavement design life, up to 40-year design period and even 100-year
design period. The interest and desire to establish a longer pavement design
life is based on the assumption that small increment of pavement thickness will
result to longer pavement service life and thus a relatively small marginal
cost of long term pavement design compared to regular designs.
Goh et al.
(2014) in their study found that the costs of applying a recycled mixture as
a base or binder course were more efficient when compared with a new
bituminous. This finding also supported by Widyatmoko (2008) believes that
recycled materials are more cost effective compared to conventional materials
yet can maintain similar pavement performance.
Stakeholders are now keen
to identify sustainable alternatives and the financial implications of
including them on a lifecycle basis. They need tools that can aid the
evaluation of investment options. However, there have not been many financial assessments
on the sustainability aspects of highway projects (Goh et al., 2014).
According to Rajamohan
(1999), highway projects are designed, constructed and operated with public
funding, therefore it is critical that economic analysis be done meticulously.
In order to decide between the projects alternatives, sound economic decisions
and detailed analysis are required in order to make the best decision. Cost
effective choice over the life of the asset becomes inevitable. Future high
costs or short life cycle of a project can offset low initial cost advantages.
The time value of money and economic analysis procedures are important in the
decision making process.
An optimal balance between
benefits and costs is crucial to achieving long-term financial viability while
ensuring the best service to road users. European Commission
Directorate-General for Regional and Urban policy under its publication
entitled “Guide to Cost-Benefit Analysis of Investment Projects – Economic
appraisal tool for Cohesion Policy 2014-2020” stated that the Cost-Benefit
Analysis (CBA) is an analytical tool for judging the economic advantages or
disadvantages of an investment decision by assessing its costs and benefits in
order to assess the welfare change attributable to it.
The CBA analytical
framework refers to a list of basic concepts which are opportunity cost and
long term perspective. The opportunity cost of a good or service is defined as
the potential profit from the best alternative, when options have to be made
between several mutually exclusive alternatives. The rationale of CBA lies in
the observation that investment decisions taken based on profit motivation and
price mechanisms to socially undesirable outcomes. On the other hand, if input,
output and external effects of an investment project are assessed at their
social opportunity costs, the return calculated is a proper measure of the
project’s contribution to social welfare. For the long
perspective, a long term reviews are adopted, ranging from a minimum
of 10 to a maximum of 30 years or more, depending on the sector of
intervention. Hence the need to set a proper time frame, forecast future costs
and benefits and adopting appropriate discount rates to calculate the present
value of future costs and benefits.
Based on the CBA report of
Smart Hospital Toolkit by Pan American Health Organization (PAHO), conducting a
CBA can be an expensive and complicated task. This will depend on the
availability of the information and data used to determine the costs and benefits
of a particular project invested. Therefore, it is highly recommended that the
potential costs of the project are significant enough to justify the allocation
of resources to forecast, measure and evaluate the anticipated benefits, costs
and impacts. In order to determine some of the input data in conducting a CBA,
certain assumptions and decisions need to be made and all of the assumptions
and methodological approach should be consistent for the various projects being
compared. Criteria need to be focused are the baseline of the benefits to be
estimated and the specific elements and activities that are relevant to CBA