Sustainable Transportation and TDM
Planning That Balances Economic, Social and Ecological Objectives
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Victoria Transport Policy
Institute
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Updated
26 July 2008
This chapter discusses the concepts of sustainability, sustainable development and sustainable transportation, and how TDM can help achieve sustainability goals. Sustainability is a planning perspective that accounts for economic, social and environmental goals, including impacts that are indirect, difficult to measure, and distant in time and space. Sustainable transportation requires more comprehensive planning than what is commonly practiced. Sustainable planning can provide an opportunity to identify strategies that can help achieve multiple goals. TDM tends to support sustainability objectives, and sustainability planning tends to support TDM implementation.
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The
earth provides enough to satisfy every person’s need but not every person’s
greed…When we take more than we need we are simply taking from each other,
borrowing from the future, or destroying the environment and other species. Mahatma Ghandi, Principle
of Enoughness |
There is growing interest in the concepts of sustainability, sustainable development, and sustainable transport. Sustainability reflects one of the most fundamental human desires supported by virtually all philosophies and religions: to create a better future world. It provides guidance for long-term, strategic decision-making. Sustainability emphasizes the integrated nature of human activities and therefore the importance of comprehensive Planning that coordinates between sectors, jurisdictions and groups. This is an important change because existing institutions are often poorly suited to address complex, long-term problems.
There is no universally accepted definition of sustainability, sustainable development or sustainable transport (Beatley, 1995). Some definitions are listed below.
Sustainable
development “meets the needs of the present without compromising the ability of
future generations to meet their own needs.”
“The
goal of sustainable transportation is to ensure that environment, social and
economic considerations are factored into decisions affecting transportation
activity.”
A sustainable transportation system is “one in which fuel consumption, vehicle emissions, safety, congestion, and social and economic access are of such levels that they can be sustained into the indefinite future without causing great or irreparable harm to future generations of people throughout the world.”
“…sustainability
is not about threat analysis; sustainability is about systems analysis.
Specifically, it is about how environmental, economic, and social systems
interact to their mutual advantage or disadvantage at various space-based
scales of operation.”
The Environmental Directorate of the OECD defines environmentally sustainable transportation as, “transportation that does not endanger public health or ecosystems and that meets needs for access consistent with (a) use of renewable resources that are below their rates of regeneration, and (b) use of non-renewable resources below the rates of development of renewable substitutes.”
Sustainable planning means that local, short-term decisions are consistent with strategic, regional and global, long-term goals.
A
sustainable transportation system is one that:
· Allows the basic access and development needs of individuals, companies and society to be met safely and in a manner consistent with human and ecosystem health, and promotes equity within and between successive generations.
· Is Affordable, operates fairly and efficiently, offers a choice of transport mode, and supports a competitive economy, as well as balanced regional development.
· Limits emissions and waste within the planet’s ability to absorb them, uses 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.
The Transportation Association of Canada proposes that a sustainable transportation system has the following characteristics:
(a) in the natural environment:
· limit emissions and waste (that pollute air, soil and water) within the urban area’s ability to absorb/recycle/cleanse;
· provide power to vehicles from renewable or inexhaustible energy sources. This implies solar power over the long run; and
· recycle natural resources used in vehicles and infrastructure (such as steel, plastic, etc.).
(b) In society:
· provide equity of access for people and their goods, in this generation and in all future generations;
· enhance human health;
· help support the highest quality of life compatible with available wealth;
· facilitate urban development at the human scale;
· limit noise intrusion below levels accepted by communities; and
· be safe for people and their property.
(c) In the economy:
· Be financially affordable in each generation;
· Be designed and operated to maximize economic efficiency and minimize economic costs; and
· help support a strong, vibrant and diverse economy.
Sustainability
has been identified as “The capacity for continuance into the long term
future.” Anything that can go on being done on an indefinite basis is
sustainable. Anything that cannot go on being done indefinitely is
unsustainable. The practices of the world's populace are currently
unsustainable.
If
we do not reach a point where our activities are sustainable, then we will
eventually consume all available resources and generate a level of pollution
that will mean the earth is no longer capable of sustaining human life.
Within
a sustainable society it is also expected that every individual will have a
right to “a better quality of life,” which would include having adequate food,
education, employment and housing, and for this to occur stable economic growth
will be required. The challenge is to decouple social progress and economic
growth from resource depletion and adverse environmental impacts.
The
UK Government has set out the following 4 pillars of sustainability:
· Social progress for everyone.
Concern about sustainability can be considered a reaction to increased specialization in the way institutions are organized, and the tendency of decision-makers to focus on easily measured goals and impacts, while ignoring those that are indirect or more difficult to measure (Measuring Transportation). Conventional planning often reflects a “reductionist” approach, in which a particular organization or individual is responsible for dealing with a particular problem. This may be appropriate in some situations, but it often results in solutions to one problem that exacerbate other problems, or failure to implement solutions that provide modest but multiple benefits. Sustainable decision-making can therefore be described as Comprehensive Planning that considers a variety of goals and impacts regardless of how difficult they are to measure. Sustainable planning and economics often refer to the triple bottom line, meaning consideration of economic, social and environmental impacts.
Conventional planning typically uses a 5-20 year time-frame, less than one generation. Sustainability incorporates concerns about long-term risks, such as depletion of resources, harmful pollution and climatic change that may harm people decades or even centuries in the future. This reflects concerns over “intergenerational equity” (i.e., being fair to future generations). But if future equity and environmental quality are concerns, it makes little sense to ignore equity and environmental impacts that occur during this generation to people in other regions or cultures. Thus, sustainability ultimately reflects the goals of Equity, ecological integrity and human welfare, regardless of time or location.
Sustainable economics maintains a distinction between growth (increased quantity) and development (increased quality). Growth assumes that the goal is to replicate what currently exists at a larger scale – bigger is better. Development assumes that the goal is improvement, which may involve expansion or contraction to an optimal scale.
Economic growth focuses primarily on market activities, while economic development also considers non-market social and ecological activities (Daly 1996). Sustainable development focuses on social welfare outcomes, such as education and health, rather than relying on material wealth as an indicator of development. Unlike neoclassic economics, sustainable economics does not strive for ever increasing consumption, but rather for sufficiency. As a result, it questions common economic indicators such as Gross Domestic Product (GDP), which measure the quantity but not the quality of market activities. For example, GDP counts medical costs and environmental cleanup as positive economic activity, but assign no positive value to actions that prevent illness or environmental degradation. Sustainable development indicators attempt to take into account qualitative and non-market values (Cobb, Halstead and Rowe, 1998).
Conventional planning tends to ask, “Does it work?” Sustainability planning tends to ask “Does it fit?” That is, sustainability planning places greater emphasis on how individual decisions fit into the overall context of total long-term goals and objectives.
Conventional economics defines people primarily as consumers, with the implication that the way to improve social welfare (i.e., to make people better off) is too maximize consumption of market goods (as reflected in GDP). Sustainable economics recognizes that people are also community members, residents, and citizens who also value non-market goods and community resource. For example, many people value friendship, security and tradition, and will forego material wealth to achieve them. The relative value of these non-market goods tends to increase as people become wealthier, since their most basic physical needs are already met. For example, an increase of $1,000 in annual income tends to provide far greater benefit to somebody who only earns $10,000 a year than to somebody earning $100,000 a year, since the wealthier person already has their basic material needs met (this is called declining marginal benefit). As a result, as a region becomes more economically developed and wealthier, the relative value of additional market goods tends to decline, while the relative value of non-market goods tends to increase.
Sustainability is sometimes defined narrowly. Some studies of sustainability focus on long-term resource depletion and air pollution problems, on the grounds that they represent the greatest risk and are prone to being neglected by conventional planning (TRB, 1997). But sustainability is increasingly defined more broadly to include the range of issues listed in Table 1.
Table 1 Sustainability Issues
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Economic |
Social |
Environmental |
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Affordability Resource efficiency Cost internalization Trade and business activity Employment Productivity Tax burden |
Equity Human health Education Community Quality of life Public Participation |
Pollution prevention Climate protection Biodiversity Precautionary action Avoidance of irreversibility Habitat preservation Aesthetics |
This table lists
various sustainability issues.
Although Table 1 implies that each issue fits into a specific category, in practice they often overlap. For example, pollution prevention is an environmental concern, but it also protects human health (a social concern) and is important for fishing and tourism industries (economic concerns). Sustainable planning reflects the realization that impacts and objectives often interact, so solutions must reflect integrated analysis.
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Who Is More
Sustainable? Who
is more sustainable, somebody who drives a fuel-efficient vehicle high annual
miles, or somebody who drives an inefficient vehicle low annual miles? If sustainability is defined only in terms of
fuel efficiency and related emissions, it can be achieved by driving a fuel
efficient vehicle, such as a 60 mile-per-gallon (MPG) hybrid car. However,
such a car does not reduce traffic congestion or the barrier effect (delay
and risk to pedestrians and cyclists), road and parking requirements,
accident risk, or sprawl. A motorist who lives in a more accessible location
and relies on alternative modes as much as possible (for example, commuting
by bicycle, carpool or transit most days) and so drives an average efficiency
vehicle low annual miles, consumes a similar amount of fuel, but imposes far
lower costs on society overall. |
Principles reflect fundamental goals and practices. Below are basic principles of sustainability planning.
· Comprehensive Analysis. Sustainability requires
planning that considers economic, social and environmental impacts, including
those that are indirect, long-term and nonmarket. This requires adequate
information and evaluation tools that allow stakeholders and decision-makers to
understand the effects of their decisions.
· Integrated and Strategic
Planning.
Sustainability planning requires that individual decisions support a
community’s long-term strategic objectives. For example, transportation
planning decisions should be subordinate to strategic economic, social and land
use plans.
· Focusing on Goals,
Performance and Outcomes. Sustainability requires that planning be based on goals and outcomes,
such as improved social welfare, ecological health and access. It does not
limit analysis to financial impacts and market activities.
· Consideration of Equity. Sustainability emphasizes
that Equity impacts should be considered in
decision-making, including those that are indirect and long-term (imposed on
future generations).
· Market Principles. Market
Principles include consumer choice, full-cost pricing and economic
neutrality can support sustainable outcomes. This requires Market
Reforms that eliminate incentives to over-use of natural resources and to
degrade the environment.
·
Precautionary Principle. Sustainability supports the Precautionary Principle,
which emphasizes the importance of incorporating risks in decision-making and
favoring policies that minimize such risks when possible. It values Resilience.
· Conservation Ethic. Sustainability favors
solutions that increase efficiency and reduce resource consumption, due to
uncertainties about future market conditions and environmental impacts.
·
Transparency, Accountability and Public Involvement. Sustainability requires a
clearly defined, transparent planning process, adequate opportunities for
stakeholder to become informed about issues and be involved in decision-making,
and good communication between professionals and the general public.
Many organizations have developed recommended best practices for sustainable planning. The U.K. Royal Academy of Engineering provides the following principles of Engineering for Sustainable Development (RAE, 2005). See the report for detailed information on these principles.
1. Look beyond your own
locality and the immediate future
2. Innovate and be creative
3. Seek a balanced solution
4. Seek engagement from all
stakeholders
5. Make sure you know the needs
and wants
6. Plan and manage effectively
7. Give sustainability the
benefit of any doubt
8. If polluters must pollute …
then they must pay as well
9. Adopt a
holistic,‘cradle-to-grave ’approach
10. Do things right,having
decided on the right thing to do
11. Beware cost reductions that
masquerade as value engineering
12. Practice what you preach.
Various sets of indicators have been proposed and applied to
evaluate sustainability. They expand on existing indicators, such as GDP, to
account for diverse social goals and objectives (Redefining Progress). These
include specific, measurable indicators that reflect progress toward community
development objectives. Table 2 is an example of a Genuine Progress
Indicator developed for
Table 2 Sustainability Indicators
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Economic |
Social |
Environmental |
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Economy, GDP and Trade Economic growth (GDP) Economic diversity Trade Personal Consumption Expenditures, Disposable Income and Savings Disposable income Personal expenditures Taxes Savings rate Money, Debt, Assets and Net Worth Household Debt Income Inequality, Wealth, Poverty and Living Wages Income distribution Poverty Public and Household Infrastructure Public infrastructure Household infrastructure Employment Weekly wage rate Unemployment rate Underemployment Transportation Transportation expenditures |
Time Use Paid work time Household work Parenting and eldercare Free time Volunteerism Commuting time Human Health and Wellness Life expectancy Premature mortality Infant mortality Obesity Suicide Suicide Substance Abuse: Alcohol, Drugs and Tobacco Drug use (youth) Auto Crashes and Injuries Auto crashes Family Breakdown Divorce Crime Crime Gambling Problem gambling Democracy Voter participation Intellectual & Knowledge Capital Educational attainment |
Energy Oil and gas reserve life Agriculture Agricultural sustainability Forests Timber sustainability Parks and Wilderness Parks and wilderness Fish and Wildlife Fish and wildlife Wetlands and Peatlands Wetlands Peatlands Water Resource and Quality Water quality Energy Use Intensity and Air Quality Energy use intensity Air quality-related emissions Greenhouse gas emissions Carbon Budget Carbon budget deficit Municipal and Hazardous Waste Hazardous waste Landfill waste Ecological Footprint Ecological footprint |
This table summarizes Genuine Progress Indicators used to evaluate sustainability.
Transportation facilities and activities have significant sustainability impacts, including those listed in Table 3. As a result, strategies that increase transportation system efficiency and reduce negative impacts from transportation are among the most effective ways to make progress toward sustainability objectives.
Table 3 Transportation Impacts on
Sustainability
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Economic |
Social |
Environmental |
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Traffic congestion Mobility barriers Crash damages Transportation facility costs Consumer transportation costs Depletion of non-renewable resources |
Inequity of impacts Mobility disadvantaged Human health impacts Community cohesion Community livability Aesthetics |
Air pollution Climate change Habitat loss Water pollution Hydrologic impacts Noise pollution |
This table lists impacts that transportation activities tend to have on sustainability objectives.
Because transportation activities have so many impacts related to sustainability, it is important to identify strategies that help achieve multiple objectives, and avoid those that solve one transportation problem but exacerbate others (Comprehensive Planning). For example, a policy or program that reduces traffic congestion but increases air pollution emissions or crashes cannot be considered a sustainable solution. Similarly, a strategy that reduces energy consumption and air pollution emission, but increases traffic congestion, crashes and consumer costs is not necessarily a sustainable strategy. The most sustainable strategies are those that simultaneously help reduce traffic congestion, pollution, crashes and consumer costs, increase mobility options for non-drivers, and encourages more efficient land use patterns, or at least avoid contradicting these objectives (Win-Win Transportation Solutions).
Conventional planning tends to assume that transport progress is linear, consisting of newer, faster modes that displace older, slower modes as illustrated below. This series model assumes that the older modes are unimportant, and so, for example, there is no harm if increasing automobile traffic causes congestion delay to public transit or creates a barrier to pedestrian travel. From this perspective it would be backward to give public transit or walking Priority over automobile travel.
Walk è Bicycle è Train è Bus è
Automobile è Improved
Automobiles
Sustainable reflects a parallel model, which assumes that each mode can be useful, and strives to create balanced transport systems that use each mode for what it does best. Transport progress therefore involves improving all useful modes, not just the newest mode, as illustrated below. For example, in many cities the most beneficial transportation strategies may involve Improving Walking and Cycling, Support for Public Transit Use, and Restricting Automobile Traffic in congested urban areas. It does not assume that faster, motorized modes should have priority over slower modes, or that increased travel speed is necessarily more important than qualitative factors such as comfort, safety and equity.
Walk è
Improved Walking Conditions
Bicycle è Improved Cycling Conditions
Train/Bus è Improved Public Transit Service
Automobile è Improved Automobile Travel
Conditions
Sustainability and sustainable transportation are difficult to measure directly, so various Performance Indicators are used to evaluate them. Some are relatively narrow, focusing on just a few impacts, such as air pollution emissions, while others attempt to represent a broader range of economic, social and environmental objectives (Gilbert and Tanguay, 2000; Gudmundsson, 2001; Litman, 2003). Below are examples of indicators.
· Quality of overall Accessibility (ability to reach desired goods, services
and activities). More is better.
· Land Use Mix - Number of job opportunities
and commercial services within 30-minute travel distance of residents. Higher
is better.
· Land use accessibility - Average number of basic
services (schools, shops and government offices) within walking distance of residences.
Higher is better.
· Children’s accessibility - Portion of children who can
walk or bicycle to Schools, shops and parks from their
homes. Higher is better.
· Electronic accessibility - Portion of population with
Internet service (Telework). Higher is better.
· Commute speed - Average commute travel time.
Lower is better, particularly for disadvantaged populations.
· Transport diversity - Variety and quality of
transport Options available in a community. Higher is
better.
· Mode split - Portion of travel made by
walking, cycling, rideshare, public transit and telework. Higher is better.
· Transit service – Public transit service
quality, including coverage (portion of households and jobs within 5-minute
walking distance of 15-minute transit service), service frequency, comfort
(portion of trips in which passenger can sit and portion of transit stops with
shelters), affordability (fares as a portion of minimum wage income), information
availability, and safety (injuries per billion passenger-miles) (Transit Evaluation).
· Motor Transport Options - Quantity and quality of
airline, rail, public transit, ferry, rideshare and taxi services. Higher is
better.
· Congestion delay - Per capita traffic Congestion delay. Lower is better.
· Consumer Transport costs - Portion of household
expenditures devoted to transport (Transport Costs).
Lower is better.
· Affordability
- Portion
of household expenditures devoted to transport, including vehicle expenses,
fares, residential parking costs, and taxes devoted to transport; particularly
by people who are economically, socially and physically disadvantaged. Lower is
better, particularly for disadvantaged populations.
· Facility costs - Per capita expenditures on
roads, traffic services and parking facilities (Transport
Costs). Lower is better.
· Freight and commercial
transport efficiency – Speed, quality and affordability of Freight and
commercial transport. Higher is better.
· Delivery services - Quantity and quality of
delivery services (international/intercity courier, and stores that offer
delivery). Higher is better.
· Market principles - Degree to which transport
systems reflect Market Principles, including prices
that reflect full costs and neutral tax policies. Higher is better.
· Planning Practices - Degree to which transport
institutions reflect Least-cost planning and investment
practices. Higher is better.
· User rating - Overall satisfaction
rating of transport system and services by users (Surveys).
Higher is better.
· Citizen involvement - Public involvement in
transport Planning process. Higher is better.
·
Crash costs - Per capita crash fatalities, disabilities and monetized Crash Costs. Lower is better.
· Planning process - Range of solutions
considered in transport Planning. Higher is better.
· Health
and fitness - Portion of population that regularly uses active transport modes
(walking and cycling). Higher is better.
· Community
Livability - Degree to which transport activities increase community livability
(local environmental quality). Higher is better.
· Cultural Preservation - Degree to which cultural
and historic values are reflected and preserved in transport planning
decisions. Higher is better.
· Basic
Access – Quality of transport to access socially valuable activities such
as medical services, education, employment and essential shopping, particularly
for disadvantaged populations.
· Horizontal Equity (fairness)
- Degree to
which prices reflect full costs unless a subsidy is specifically justified (Equity). Higher is better.
· Progressivity - Degree to which transport
policies make lower-income people relatively better off (Equity).
Higher is better.
· Mobility for non-drivers - Quality of accessibility and
transport services for non-drivers (Equity). Higher is
better.
· Mobility for people with
disabilities) - Quality of transport facilities and services for people with
disabilities, such as wheelchair users and people with visual impairments (Universal Design). Higher is better.
· Nonmotorized transport - Quality of walking and
cycling conditions (Non-motorized Evaluation). Higher
is better.
· Climate change emissions - Per capita fossil fuel
consumption, and emissions of CO2 and other climate change emissions (Energy and Emission Reductions). Lower is better.
· Other air pollution - Per capita emissions of “conventional” air
pollutants (CO, VOC, NOx, particulates, etc.) (Energy and
Emission Reductions). Lower is better.
· Noise pollution - Portion of population
exposed to high levels of traffic noise. Lower is better.
· Water pollution - Per capita vehicle fluid
losses. Lower is better.
· Land use impacts - Per capita land devoted to
transportation facilities (Land Use Evaluation). Lower
is better.
· Habitat protection - Preservation of high-quality
wildlife habitat (wetlands, old-growth forests, etc.) from loss due to
transport facilities and development (Land Use Evaluation).
Higher is better.
· Roadway aesthetic conditions
(people tend to be more inclined to care for environments that they consider
beautiful and meaningful).
Sustainability objectives have several implications for transport planning.
Sustainable transportation planning requires a paradigm shift: a fundamental Change in the way people think about and solve problems (Litman, 1999). It requires more comprehensive analysis of impacts, consideration of indirect and cumulative impacts (Louis Berger & Associates, 1998), consideration of demand management solutions, and public involvement in transportation decision-making. It involves Prioritizing Transportation to give higher value trips and lower cost modes priority over lower value, higher cost trips.
Automobile dependency is defined as high levels of automobile use, automobile oriented land use, and a lack of travel alternatives (Newman & Kenworthy, 1999). Automobile dependency imposes a number of economic, social and environmental costs (Litman, 2000), and results in part due to distortions in transportation and land use markets (Market Principles) (TRB, 1997). Sustainable transportation requires reducing these distortions and encouraging the development of a more balanced transportation system (Evaluating Transportation Choice). Transportation Market Reforms that correct market distortions which cause excessive automobile use and automobile oriented land use patterns can increase Economic Development while also achieving social and environmental objectives.
Equity is a fundamental goal of sustainable development. Sustainable development reflects a desire to consider the impacts that our current decisions could have on future generations, called intergenerational equity. Sustainable transportation therefore requires that broad equity analysis be incorporating explicitly in transportation planning (Evaluating TDM Equity).
Transportation patterns can be affected significantly by land use patterns (Land Use Impacts on Transportation). In particular, low density development, hierarchical street patterns, generous road and parking capacity, and automobile oriented site design tends to increase automobile dependency, leading to high levels of per capita motor vehicle mileage and a reduction in the quality of travel alternatives (transit, walking and cycling). Many experts conclude that sustainable transportation requires more Accessible land use (Newman and Kenworthy, 1999).
Sustainable transportation planning tends to be particularly important in lower-income, Developing Regions, since they have more limited resources, tend to rely more on alternative travel modes, and are