TRANSPORTATION AND SUSTAINABILITY-THE TRIPLE BOTTOM LINE A sustainable transportation system does the following: Allows the basic access needs of individuals and societies to be met safely and in a manner consistent with human sound health, and within and between generations. Limits emissions and waste within the planet s ability to absorb them, minimizes consumption of non-renewable resources to the sustainable yield level, reuses and recycles its components, and minimizes the use of land and the production of noise. Is affordable, operates efficiently, offers choice of transport mode, and supports economic growth. Such sustainability improvements around transportation may not be achieved quickly. It is important to consider Triple Bottom Line framework which helps to guide planning, policy decisions, and implementation of necessary steps for developing a sustainable outcome. When thinking about delivering transportation solutions and infrastructure in a more sustainable manner, agencies and companies are considering each of the bottom line elements: ECONOMY Support economic vitality while developing infrastructure in a costefficient manner. Costs of infrastructure must be within a society s ability and willingness to pay. User costs, including private costs, need to be within the ability of people and households to pay for success. SOCIAL Meet social needs by making transportation accessible, safe, and secure; include provision of mobility choices for all people (including people with economic disadvantages); and develop infrastructure that is an asset to communities. ENVIRONMENT Create solutions that are compatible with - and that can be an enhancement to - the natural environment, reduce emissions and pollution from the transportation system, and reduce the material resources required to support transportation.
PRACTICAL DISCUSSION The concept of sustainability is dependent on an understanding of the notion of sustainable development an approach, a process, which considers benefits of current and future generations. This implies an emphasis on measuring progress towards specific goals. Sustainable transport system can be explained as "one which is developed so that the effect of its consequences on the social, economic and environment are managed and balanced to achieve an improvement in the system".. In this context, we can regard "sustainability" as important principle, under which the following aspects are addressed: Community needs Economic development Environmental impact Public health Mobility Safety An important emphasis is the long-term forward-looking "improvement" focus not just containing the system (and its consequences) to the current level, but seeking to make it better What does this mean for providing and managing a transport system in a sustainable manner? Consider two broad approaches: reducing the adverse impacts of transport operations, improving energy efficiency and conservation. Several external factors will exert great influence on these approaches, for example: changes in energy resources fuel prices air quality transport operational practices (particularly for goods). In taking into account such external influences, countries will need to have in place the essential elements (policies, management practices) and apply them so that trends emerge which indicate progress towards sustainable development of the transport system. These trends
would include, for example: Reducing the rate of traffic growth Reducing consumption of non-renewable fuel Reducing individual car use Increasing efficiency of goods transport Increasing use of public transport Improving affordability of transport services Improving air quality Reducing levels of risk (and numbers) of death and serious injury Strategies for achieving these might well be in conflict in some cases, and complementary in others. What does this mean for a sustainable approach to road safety engineering? What specific trends do we need to see reflected as a result of road safety engineering practice? A SUSTAINABLE APPROACH We can consider road safety engineering in accordance with the notion of a sustainable transport system. We can develop that in terms of what we can do in engineering management for road safety, and outline an approach for pursuing that. We may define sustainable road safety engineering as "a process whereby the development of the road environment keeps pace with the demands of the transport task, such that crashes and casualties on the road network are continually reduced, ultimately to acceptable levels of risk". Several alternative definitions could be derived along similar lines that might provide a better or more comprehensive explanation of the concept. The definition includes the notion of continuous development and improvement. We can also consider what the individual elements of the definition mean and what it implies for actions that need to be taken. The road environment refers to the roadway itself, the roadside environment, the management of traffic on it, and the adjacent land use.
The demands of the transport task refers to the requirements for movement of people and goods, the traffic mix (road users, vehicle types), traffic growth, freight trends, and intermodal (eg. road/rail) aspects. Analyzing crashes requires an understanding of the location and incidence of events, details of road user or vehicle types involved, factors which contribute, and an assessment of the outcomes and costs. The road network refers to the diversity of road types from a functional perspective major arterial routes at one end, local access streets at the other and the different requirements in terms of capacity, design, and safety. We also need to recognize the different factors (eg.land use) which modify or influence how we meet those requirements. The development of the road environment refers not only to the planning, design and construction of new roads and facilities. It also refers to how the existing network may be adapted to accommodate changing transport demands, how we manage the traffic it carries, and how we maintain and manage the asset it represents. Keeping pace with the demands of the transport task from a safety perspective, implies keeping abreast of latest developments as indicated by research and analysis, and experience in comparable jurisdictions. This includes identifying and developing opportunities for technology transfer in variety of areas for example, real-time variable signing, data communications, and enforcement techniques. An underlying imperative is for the network and its management to be responsive to change and the needs identified from monitoring safety performance. The notion of "keeping pace" may be regarded as reactive. One should also consider "setting the pace" - this implies the need to develop transport policy settings which directly influence the demands on the transport system and the way it operates. These would be reflected in demand management strategies ranging from encouragement of travel behavior change to direct pricing initiatives. Continual reduction of crashes and their consequences within certain limits and/or in pursuit of set target levels (frequencies, rates, other outcomes) implies an ability to properly measure performance and analyze details of performance so that progress and improvements can be clearly demonstrated. This requires a strategic approach to setting desired and achievable outcomes. 4
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