Environmental Engineering Reference
In-Depth Information
The effectively designed sustainable pavement should aim to:
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Minimize the use of natural resources
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Reduce energy and fuel consumption during construction and operations
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Minimize greenhouse gas (GHG) emissions
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Limit pollution (air, water, earth, noise, etc.)
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Improve health, safety and risk prevention
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Ensure a high level of user comfort and safety
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Provide long term value for money
Historically, most municipal governments have been forced by political pressure
and scarce financial resources into a short-term approach toward pavement design
and management. They have also relied heavily of traditional or 'recipe' design
methods. This has led to a cycle of acceptance of pavements that lose ride quality
very quickly and need major rehabilitation every 18 to 25 years. Even the conven-
tional life cycle cost analysis process frequently fails to fully demonstrate the folly
of a short-term design philosophy when it comes to pavements. The twenty-first
century realities of excessive energy consumption, dwindling natural resources,
environmental impacts of construction and the importance placed by the public on
making our roads safer, rarely get factored into the analysis. Nor do the indirect
costs sustained by the motorist in maintaining vehicles that are habitually driven on
bad roads and the extra fuel consumption as a result of traffic delays from road
repair activities get considered. This paper describes a more enlightened approach
for pavement design for high volume urban motorways.
Road Transportation and Sustainability
Sustainability principles have application to every stage of road planning, develop-
ment, construction, operations and maintenance. Some examples include longer
lasting pavements, intelligent transport systems, alternative fuels, improved safety
features to reduce accidents, and incentives for car pooling. In the past, options for
the development of public road networks were largely dictated by economics. In the
last 30 years or so, environmental and social impacts have had an increasingly large
influence on road design policies and standards. More recently, context sensitive
design principles have also begun to influence traditional design approaches
[1]
.
Sustainability when applied to road transportation needs to be broad ranging and
must consider a wide range of themes under the broad categories of economic,
social and environmental aspects.
Today's economic activity is based on a legacy of facilities and infrastructure.
Progress towards sustainability will be a long journey and will only be achieved on
a project by project basis and by joint co-operation between owners and their
engineers. Progress towards sustainability goals is measured under three main
categories: environmental, social and economic. The implementation of this
approach is focused on achieving a balance between these categories, rather than
achieving one at the expense of another, as illustrated in Fig.
1
.
