Sustainable Transport – The Need for a Common Definition
For a long time transport played a marginal role in the discussions on the Global/UN level. In the 1992 Rio Conference on Environment and Development transport was not explicitly formulated as a Sustainable Development Goal (SDG). The UN Commission for Sustainable Development (CSD) concluded that there is no accepted single definition of sustainable transport and especially its measurement in terms of indicators.
A clear definition of sustainable transport is important to ensure that transport decisions reflect the basic concepts of sustainable development. To be effective, this definition must be comprehensive but also easy to understand and apply in various contexts and conditions (Litman 2010).
From the perspective of the 3 key pillars of sustainability – economic, social and environmental, Marc Juhel (2012) relates the following characteristics to these three pillars of a sustainable transport system, while being framed by a level of sustainability in governance.
The Three Pillars of Sustainable Transport
A sustainable transport definition should reflect the extent to which an overall transport system contributes toward sustainable development. It should therefore:
• Build on the basic principles of sustainable development;
• Reflect all dimensions of sustainable development (environmental, economic and social)
• Reflect both positive and negative impacts;
• Reflect the concept of “accessibility” rather than considering mobility an end in itself;
• Recognise that a sustainable transport system is diverse and efficient, and uses each mode of travel for what it does best (walking and cycling for local travel, public transport for travel on busier corridors, and automobile travel when it is truly efficient).
This leads to the following (preliminary) definition, suggested by Litman and Replogle :
Sustainable transport enables access to goods and services that support equitable development while limiting short and long term adverse consequences for environmental, social and economic services and systems.
Moreover GTZ (2004) defines a Sustainable Transport System as one that…
… “allows individuals, companies and societies to meet their basic mobility needs in a way that preserves human and ecosystem health, and promotes equity within and between successive generations.
… is affordable, efficient, offers a choice of transport mode and supports a competitive economy as well as balanced regional development – and
…limits emissions and waste within the planet’s ability to absorb them, use renewable resources at or below their rates of generation, and uses non-renewable resources at or below the rates of development of renewable substitutes, while minimizing the impact on the use of land and the generation of noise” (GTZ Sourcebook Module 5e)
Considering the above definitions, a Sustainable Development Goal, set by the United Nations can call for “Universal Access to Safe, Clean and Affordable Transport”.