Definitions

"Sustainable development" has been defined in various ways. The simplest statement of the best-known definition is:

...meeting the needs of the present without compromising the ability of future generations to meet their own needs, balancing and integrating a prosperous economy, a quality environment, and social equity... the "3 E's" of sustainability. 1

By "sustainable transportation" we mean a transportation system that:

1. allows the basic access needs of individuals to be met safely and in a manner consistent with human and ecosystem health, and with equity within and between generations;

2. is affordable, operates efficiently, offers choice of transport mode, and supports a vibrant economy;

3. limits emissions and waste within the planet's ability to absorb them, minimizes consumption of non-renewable resources, reuses and recycles its components, and minimizes the use of land and the production of noise. 2

Indicators

Indicators are an increasingly popular way to present information about a community or region. Indicators are a way to summarize valuable data into an easily readable format. Indicators are used to clarify specific issues by presenting key data concisely.

Indicators have been an important part of governmental policy for decades. Only recently have indicators of sustainability and other measures of "quality of life" gained increasing attention.

Transportation indicators measure the transportation system. Sustainable transportation indicators are those that demonstrate the vital relationship between transportation networks and the ecology, economy, and society in which they are located and serve. This study defines sustainable transportation indicators (STIs) as regularly updated performance measures that help transportation planners and managers take into account the full range of economic, social, and environmental impacts of their decisions [emphasis added].

Study Purpose, Method and Results

Despite the proliferation of indicators-and the proliferation of interest in indicators-there have been only very few and scattered attempts to develop comprehensive sustainability indicators for transportation systems, and none that have built up from the measures and indicators already collected by local and regional transportation agencies in California. This research addresses this gap, seeking out and examining critically sustainable transportation indicators that may be effective and practicable in California. In so doing, it builds on both recent research and practice throughout the U.S., Canada and Europe.

The literature on "sustainable development," "sustainable transportation," and "sustainable transportation indicators" was reviewed as the basis for preparing a survey regarding an array of candidate sustainable transportation indicators. This survey was administered to a selection of transportation planning and program management professionals. In addition, several case studies of agency programs relating to sustainable development, transportation planning and operations, and the use of indicators were conducted, including review of their documents and interviews of agency staff and representatives.

Survey Results

A list of 31 promising transportation performance indicators gleaned from the literature are examined in this report (Table 1-1).

A survey was conducted to explore transportation professionals' perceptions regarding sustainable transportation indicators. The results of the survey provide insights useful in developing performance indicators for local and regional transportation agencies. The survey was used to gain insight into how transportation agency directors and other key staff define sustainable transportation and view the importance of implementing sustainable transportation indicators.

Background

This research project explores a variety of measures and indicators as tools for implementing sustainable local, regional and statewide transportation systems in California. The terms "performance measures" and "performance indicators" are often used interchangeably. As used in this discussion, a performance indicator is a performance measure with particular usefulness in policymaking-a measure that indicates a policy direction. The focus will be on developing performance indicators for local and regional government surface transportation agencies (both planning agencies and operating agencies). The results should be relevant for statewide transportation planning and the private sector as well.

Sustainability (which subsumes the related concept of Sustainable Development) represents an increasingly pervasive (some would say dominant) paradigm in many fields closely related to transportation, from urban and regional planning to global economic development theory and practice. Sustainability is clearly the dominant paradigm in the environmental movement, at all scales of analysis and action, from global to local.

While there are many definitions of sustainability, the simplest statement of the best-known definition is "meeting current needs without jeopardizing the ability of future generations to meet their own needs" [emphasis added]. 3 This definition has been broadened to include the integration and balancing of social, economic and environmental objectives so as to ensure the long-term viability of social, economic and natural systems. While the preservation of natural systems is often emphasized in the literature and in public debates about sustainability, sustainability is not mere environmentalism. The environment, the economy, and social equity are equally important aspects of sustainability.

Transportation has a major under-appreciated role to play in the pursuit of sustainability. According to the U.S. Department of Energy:

Many communities have reached a crossroads. If they build a new highway, traffic will stop backing up-at least that's the initial rationale. Citizens will stop calling to complain. Everyone presumably will be satisfied-for a while. This "solution," however, is short-lived.

When pavement is laid, more vehicles come. With more vehicles comes more smog. Automobiles are a major contributor to global warming. Their pollution also causes severe health problems for many. Traffic congestion, already costing us an estimated $168 billion annually in lost productivity, is expected to triple in coming years, wasting more productivity and fuel and worsening our air quality.

Our automobile habits have caused increasing dependency on oil imports, much of it coming from unstable parts of the world. In 1970, 23 percent of America's petroleum was imported. Today, we import more than 54 percent of our petroleum needs, and this number is estimated to reach more than 60 percent by 2010. The cost of oil imports to U.S. consumers totals some $50 billion annually. And in addition to the cost of oil imports, the cost of productivity loss, and the cost of congestion, we must add other social costs of transportation, such as traffic deaths and injuries, and pollution. 4

Sustainable transportation has much in common with Transportation Systems Management (TSM). The TSM philosophy recognizes that transport systems have carrying capacities that must be respected, because they are not easily nor cheaply expanded. This is also the philosophy of sustainable transportation.

Sustainability is still less central to transportation studies than it is to many allied fields, but change is evident. A search on the comprehensive (TRIS) database in 1990 revealed only two publications containing keyword variations of "sustainability," a search in early 2001 revealed over 130, and a search on December 8, 2002 revealed just over 200. It is noteworthy that the majority of these citations was focused on transportation projects overseas, with Europe particularly well represented.

Performance measures and indicators have been in widespread use by many transportation firms and government transportation agencies for decades. Indicators are especially prevalent in the field of public transportation, which is understandable since local, state, and federal governments subsidize public transit, and each level of government requires documentation of performance against specified criteria and measures. Primary examples include transit Performance Audits performed under California's Transportation Development Act (TDA), and the Federal Transit Administration's (FTA) National Transit Database (formerly Section 15) performance reporting requirements, which are mandatory for all federally funded transit operations.

Performance indicators also have a long history in the development of highway systems. The concept of the cost-benefit ratio-a classic example of a performance indicator-has been a mainstay of highway planning for half a century.

While transportation measures in use today were not devised with sustainability in mind, all have a bearing on sustainability, and it is a fundamental premise of the proposed research that effective indicators will build on indicators already in use. The literature on indicators shows overwhelmingly that to be effective, indicators must be developed within an agency, not imposed from without. 5

In the past decade, performance indicators for roadways have also taken a turn toward sustainability. Both the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) and its successor legislation, the Transportation Efficiency Act for the 21st Century (TEA-21), place a heavy emphasis on minimizing the impacts of transportation to human and natural environments-fundamental aspects of sustainability. The transportation legislation of the 1990s also emphasizes maintaining and maximizing the efficient use of existing transportation-another aspect of sustainability. Many performance measures have been devised to serve these ends. While many management systems and performance indicators associated with the original ISTEA are no longer mandatory, many roadway agencies in California have developed and continue to refine management systems in which performance indicators play a key role.

The sustainability indicators movement also came of age in the 1990s. Entire communities, including large communities (in the U.S., Seattle, Washington is a well-known example) and even entire states (e.g., Minnesota and Hawaii) adopted sustainability indicator programs. The U.S. Department of Energy and the Environmental Protection Agency have been conducting workshops on the development of "Sustainable Community Indicators" for several years. 6

THE FUNDAMENTAL ISSUE ADDRESSED IN THIS RESEARCH

Despite the proliferation of indicators-and the proliferation of interest in indicators-there have been only very few and scattered attempts to develop comprehensive sustainability indicator programs for transportation systems, and none that have built up from the measures and indicators already collected by local and regional transportation agencies in California. This research addresses this gap by seeking out and testing sustainable transportation indicators that may be effective and practicable in California. In so doing, it draws on both recent research and practice throughout the U.S., Canada and Europe.

Sustainability and Transportation

The remainder of this section concentrates on the definition of sustainability in terms of transportation, while the following chapter discusses the Sustainability Indicators movement as it applies to transportation planning and service delivery; the following section also defines the nature of sustainable transportation indicators (STIs) and defines a preliminary set of 31 STIs. The overall goal is to operationally define Sustainable Transportation Indicators in a historical context.

Neither of these chapters summarizes the full set of literature reviewed, which is contained in the Annotated Bibliography.

This discussion builds on the research team's previous study. 7 In that study it was found that statements of sustainable planning principles generally allocate a small and sometimes invisible role to transportation and transportation planning. Our previous study found that very few authors concerned with sustainability have focused on transportation planning. We now turn to three authors who were instrumental in developing our own definition of sustainable transportation, which is presented in the conclusion of this section.

CONCLUSION: SUSTAINABLE TRANSPORTATION DEFINED

The Canadian Centre for Sustainable Transportation (CST) has adopted the following definition of Sustainable Transportation. A slightly amended version of this definition was adopted by the European Union (via the Council of Ministers of Transport and Communication) in April 2001, as the 15-nation European Union's formal definition of sustainable transport: 16

A sustainable transportation system is one that:

Allows the basic access needs of individuals to be met safely and in a manner consistent with human and ecosystem health, and with equity within and between generations.

Is affordable, operates efficiently, offers choice of transport mode, and supports a vibrant economy.

Limits emissions and waste within the planet's ability to absorb them, minimizes consumption of non-renewable resources, reuses and recycles its components, and minimizes the use of land and the production of noise.

This ranks as perhaps the most elegant, and is certainly the most officially accepted definition of sustainable transportation to date. It is a useful screening definition for assessing policies and indicators.

Lee developed a definition of sustainable transportation in 2002 based on five key principles. These were gleaned from the team's review of the literature and extensive dialogue and debate regarding these issues. 17 The principles are presented in Table 2-2.

WHAT ARE INDICATORS?

Most people use indicators as a normal part of their daily activities. Indicators serve as shortcuts that allow us to better understand the world around us. Indicators can be signs, symbols, pictures, and experiences. At times, these indicators may be difficult to describe and may not carry the same significance for all individuals. For this reason, it is generally useful to focus on those indicators that can be quantified.

Quantifiable indicators are the presentation of data that illustrate important changes over time. Indicators may measure a variety of factors in a community or region including, but not limited to, infrastructure adequacy, social equity, environmental quality, economic growth, and political inclusion.

Indicators are often included in reports for individuals in positions to influence policy direction. In private industry, indicators are often presented as part of the background material prior to determining the best course of action for a business. In the public arena, indicators are included in community and regional reports. Public policy decision makers are then able to use the information as a baseline against which future actions can be measured and hopefully adjust policy decisions to improve quality of life in the community or region. Transportation agencies often have a key role in the collection and use of indicators as well. Transportation agencies, however, are more likely to focus on more microscopic issues in the short-term as compared to community and regional planners.

Why Use Indicators?

Indicators are a way to summarize valuable data into an easily-readable format. In many cases, measuring and tracking the condition of a community or region requires analysis of large databases using complex statistical methods. A substantial amount of time and energy can be expended in gathering and interpreting the results. Many individuals either do not have the background in quantitative methods necessary to understand the complex statistics or do not have the time to consider the raw data. Indicators are used to clarify specific issues by presenting key data in a concise format.

Besides the time savings and general ease-of-use, indicators can be valuable decision making tools. To understand the value of indicators, it is necessary to think beyond the data being presented. An indicator should provide an empirical view of general trends. For example, a quality indicator can be used to establish baseline information from which change can be monitored. As long as the data in the indicator is repeatedly measured, the baseline information is then a valuable tool in determining whether progress is being made toward goals.

In this way, a quality indicator is a valuable tool. It creates a standard of information on which all parties can rely. Decision makers and stakeholders may turn to the information drawn from indicators to base negotiations and decisions regarding goals and actions. Constituents, stakeholders, and shareholders can use this information to grade the success, or failure, of decision makers. In this way, indicators can heighten accountability.

Criteria for Indicators: What Makes a Good Indicator?

A good indicator should be able to establish a base of information that can be used in the policy decision-making process. Decision making is difficult when participants draw different conclusions because each part has begun with a different set of assumptions regarding the current condition of a community or region. A high quality indicator should, at minimum, be able to dispel much of the dispute over information by establishing an empirical measure on which all parties can agree.

An indicator that establishes a generally accepted empirical measure may be referred to as a descriptive indicator. For example, traffic surveys may be used to establish the level of use of different transportation modes in a community, and all members may agree that the indicator is accurate. By contrast, prescriptive indicators not only describe reality, they measure the attainment of goals and the success of policy aimed at realizing goals. For example, if a community states that automobile driver trips should not exceed 50 percent, this is a prescriptive indicator. If the current traffic survey finds 60 percent of trips are auto driver trips, this is clear evidence that a community goal is not yet obtained. If the surveys indicate that five years earlier auto driver trips were 65 percent of all trips, this establishes that progress is being made toward the goal. Prescriptive indicators require members of a community to agree on what the magnitude (or at minimum, the direction) the value of the indicator should take over time.

Indicators are intentionally designed to be shortcuts to greater understanding, and therefore inherently have some shortfalls; any summary statistic necessarily leaves out information about the reality being described. Nonetheless, good indicators are a useful, even necessary, part of public policy making.

Though indicators are as diverse as the community that creates them, good indicators have some commonalities. A good indicator should include most of the following general characteristics:

It reflects a fundamental element of community and regional well being.

Indicators are more than statistics. To have significance as an indicator, the data must measure factors that relate directly to community and regional well being. The correlation between community and regional well being and the indicator should be properly documented.

It is clear, understandable, and easy to communicate in concept.

Indicators should be clear to read and easily understood by an educated audience. It should not take a specialist to understand the significance of an indicator, given a brief explanation. A specialist, however, can be useful in interpreting the greater significance of an indicator of the long-term direction of quality of life in the community and region.

It has demonstrated value and importance to the community and region.

A quality indicator is one that is acceptable to a wide variety of audiences. Policy makers, in particular, must recognize its importance and be willing to acknowledge the conclusions drawn from it.

The data can be tracked consistently through statistical measurement at regular intervals.

Indicators should be more than one-time measurements. It is essential that the information can be tracked on a routine basis for comparison between time periods. In some cases a quality indicator may only have one year's measurements, such as when a new indicator is initiated. In this case, it is vital to establish that the indicator can and will be measured again on a regular basis.

The data should be timely.

The data collection process may entail substantial lag times. It is important that indicators provide information in time to take action. Furthermore, the ability of the community, region, or agency decision-makers to trust data that is more than a year old decreases because current experiences may contradict the data presented.

It must be feasible to gather and analyze the data.

Measuring the data must be possible. Moreover, the questions asked must be answerable through a quantifiable means, while meeting the requirement to be clear and easily understandable.

The data comes from a reliable and trusted source.

Like most data, the statistical measurements presented in indicators must be based on a sound methodology. Where surveys or questionnaires are used, proper sampling methods must be used and responses must be statistically significant with a minimal degree of error. Using trusted sources with a well-documented methodology is essential.

The information should supplement common knowledge.

The data should measure things that people cannot measure for themselves. Which is to say, indicators should add to the knowledge base and not simply reconfirm it. Sometimes, however, it may be useful to validate and quantify commonly held assumptions; a community that thinks of itself as pedestrian-friendly may be surprised by its heavy reliance on cars.

The statistical measures should be appropriate in scale.

Data measurements need to be as specific as possible while still maintaining their ability to provide trend information. The focus of indicator data should not over-generalize using the measurements of a single, small geographic region. Similarly, data for one demographic group should not be overgeneralized. On the other hand, over aggregating information in many instances will diminish its value for many policy-making decisions.

It indicates an outcome rather than an input.

Measurements of outcomes indicate the state of the factor being measured. Inputs measure what is being done to help the factor improve or deteriorate. For example, the number of laws passed providing transportation funding would not be a good indicator of transportation system conditions because it is an input into the amount of improvement being made on transportation systems. It is important that outcomes be measured to maintain the direct correlation between the indicator and community and regional well being.

With these characteristics of a good indicator in mind, we now turn to the history of indicators, and transportation's role in, and relation to, this larger history.

WHAT IS THE HISTORY OF INDICATORS?

Introduction

Indicators have been an important part of governmental policy for decades. The non-profit organization Redefining Progress points out that the Gross National Product (GNP), and later the Gross Domestic Product (GDP), have served as important barometers for assessing the state of the U.S. economy for decades. Since the 1960s, these indicators that measure "quality of life" have gained increasing attention. Indicators that attempt to measure progress of communities toward sustainability are an even more recent phenomenon.

Their recent publication The Community Indicators Handbook, Redefining Progress suggests that "it all started in 1985" in Jacksonville, Florida, when there was little interest or experience in developing and implementing comprehensive sets of indicators at any level of government. 18 In that year, a report on Life in Jacksonville: Quality Indicators for Progress was issued by the Jacksonville Community Council, Incorporated (JCCI), a non-profit, citizen-based organization. 19

The report contained data demonstrating historic patterns and current conditions related to the City's quality of life including the economy, natural environment, public health and safety, recreation and culture, and mobility, among others. The purpose of the report was to provide a tool to promote a sustainable future for the community through public policy. Over the years a number of reports have been issued by JCCI covering about 82 measurable indicators, including a category called Mobility.

Example indicators related to transportation include the percentage of working people surveyed (by telephone) who report commuting times of 25 minutes or more, average number of daily seats available on flights through the Jacksonville International Airport, average weekday miles of Jacksonville Transportation Authority bus service, and average weekday ridership on the Skyway, among other measures. Moreover, members of various indicator task forces in the past have recommended additional indicators, which do not currently have available data. These include transportation-related measures such as the average number of rides provided weekly by the coordinated special-needs transportation system, and the number of Amtrak passengers going through the Jacksonville station annually.

The ongoing efforts of JCCI remain one of the leading examples of community-based sustainability indicators in the nation. It has served as a model for many other local community efforts to establish a sustainability indicator program.
(See http://www.jcci.org/newerhome.htm).

Bruntland Sustainability and Agenda 21

Major influences in the development of sustainability indicators have been efforts of the United Nations to promote sustainable development, particularly the World Commission on Environment and Development (WCED or Brundtland Commission) and its report Our Common Future. 20 This report popularized the definition of sustainable development as "development which meets the needs of the present without endangering the ability of future generations to meet their own needs."

The growing concern about the need for sustainable global development led to the United Nations Conference on Environment and Development, or Earth Summit, in 1992 at Rio de Janeiro, Brazil. A major result of the Earth Summit was the publication of Agenda 21, a plan of action to promote sustainability across the globe in the 21st century. 21 A key component of Agenda 21 was the need for accurate and timely information for decision making in order to bridge the data gap, in the form of indicators for sustainable development. 22 Many nations adopted and attempted to implement the programs and actions of Agenda 21, including Australia, New Zealand, and many in Europe. A number of cities in the United States are committed to implementing Agenda 21, including Santa Monica, which is presented in this report as a case study.

U.S. Efforts

At the national level, initial interest in sustainable development appeared to be in response to the 1992 Earth Summit. The President's Council on Sustainable Development (PCSD) was established in 1993 by the Clinton administration, which generated a series of documents related to sustainability. One of the PCSD recommendations resulted in the establishment of the U.S. Interagency Working Group on Sustainable Development Indicators (SDI Group). In 2001, the SDI Group published Sustainable Development in the United States: An Experimental Set of Indicators. 23

The report contained a wide range of information about indicators, with limited attention to transportation. The discussion about transportation focused on an indicator related to vehicle ownership, fuel consumption, and travel per capita. This indicator was deemed important because of the high rate of vehicle ownership, which was close to one vehicle per licensed driver, and the negative impact of heavier vehicles on fuel efficiency. It underscored the important role of transportation for economic production and distribution and for personal mobility. The indicator reflected an increase in both per capita motor vehicle registrations and annual miles traveled between 1960 and 1998.

The sustainability movement in the United States has not been strong, compared to other nations and local communities, especially in the development of sustainability indicators. In short, the interest in sustainability indicators in the United States has been limited, but has exhibited some activity, especially beginning in the early 1990's. For the most part, U.S. activities have been independent of Agenda 21.

California

In California, the development and implementation of sustainability indicator programs has been limited. At the state level, the California Environmental Protection Agency recently published Environmental Protection Indicators for California (EPIC), which encompass a wide range of indicators. These are under the general categories of air quality, water, land, waste and materials management, pesticides, transboundary issues, environmental exposure impacts upon human health, and ecosystem health.

Transportation is listed under "background indicators," which "do not represent particular environmental issues in themselves, but provide information with which to interpret the meaning of various environmental indicators presented in this document." 24 The Governor's Office of Planning and Research (GOPR) released a draft of the General Plan Guidelines for public review and comment, which closed December 31, 2002. The draft document contains limited reference to sustainable development and appears to blend it with smart growth and new urbanism. There is brief mention of sustainability indicators with reference to the City of Pasadena's quality of life index. 25

Outside of Santa Monica and Santa Barbara, the only other local communities in the state to register indicator programs in the literature are Pasadena, San Francisco and San Mateo. However, the City of San Diego is initiating a Sustainable Community Program, which includes a Sustainable Community Indicators element and apparently is related to Mayor Dick Murphy's Ten Goals.

The Community Environmental Council of Santa Barbara (CEC) initiated a study of community sustainability indicators in the early 1990s to determine if there was a non-political approach to establish a framework for monitoring and protecting the quality of life for the Santa Barbara region. As a result, the CEC found only 40 state and local governments attempting to set up indicator programs. 26 In looking for model indicator programs for application to the South Coast region of Santa Barbara, the CEC held two workshops to discuss the experiences of other communities in developing sustainability indicators. The CEC ultimately issued a report, Sustainable Community Indicators: Guideposts for Local Planning, focusing on three communities: Seattle, Washington; Cambridge, Massachusetts; and Santa Monica, California.

Following publication of their report, the CEC decided to establish the Sustainability Indicators Program (SIP). The effort to establish an indicator program evolved from a perceived need to protect the quality of life in Santa Barbara. Recognizing the sharp political divisions in the community over issues related to development and environmental protection, it was paramount to the CEC leadership that a nonpolitical framework be established. The framework reflected both the importance of the quality of life offered by Santa Barbara and the need for an economic conversion "as part of a defense-conversion plan to attract high-tech, high-paying jobs to the area." 27

Early in the program, 30 community members from a variety of professions and organizations were interviewed to determine the number and range of indicators they would like to see included in the SIP. From about 300 potential indicators, the number was winnowed to 35. Subsequently, five Santa Barbara South Coast Community Indicator reports have been issued through 2002. During this time, the program became known as the Santa Barbara South Coast Community Indicators Project (SCCIP). Project support has expanded to include several county agencies, cities, non-profit foundations, and the University of California. Recent reports have focused on special topics, including housing affordability, non-profit organizations, public health, and healthy lifestyles. Indicators are divided into three basic categories: economic, environmental, and social.

Transportation-related indicators are organized under Environment as Mobility and include percentage of drive-alone commuters (declining), biking and walking (increasing), commute distances for South Coast employees (increasing), bus popularity (declining), and number of cars on highway 101 (increasing). The 2002 report contained new commuting data, using a Coastal Housing Partnership survey, illustrating the relationship between home-ownership and commuting time. 28 Only 4.58 percent of all South Coast residents can afford to buy a median priced home of $699,950. 29

It remains unclear how the SCCIP will directly influence the development of sustainable community policy and implementation. The reports, and the process of obtaining and presenting indicator data, is guided by the mission statement "to involve the Santa Barbara South Coast community in developing and using social, environmental and economic indicators that will guide decisions towards continually improving our quality of life". 30 There has been no documentation to date that the SCCIP has influenced planning policy in general, or transportation policy/programs in particular, within the South Coast Region. In this regard the SCCIP falls short of the example of the indicators program developed by Seattle in the 1990s.

Sustainable Seattle

Sustainable Seattle represents one of the best-known local community efforts to establish an index of sustainability indicators in the United States. In response to a 1990 conference held by the Global Tomorrow Coalition in Seattle, a group of interested people established the Sustainable Seattle Network and Civic Forum. This group sponsored a diverse civic panel of 150 community leaders to prepare a set of indicators to help "protect and improve our area's long-term health and vitality by raising awareness of the links between economic prosperity, social equity, and environmental carrying capacity." These indicators would serve "to educate ourselves and other citizens about the values, principles, and practices of sustainability and to monitor the region's progress towards a more sustainable way of life." More than 200 people, investing over 2,500 hours of volunteer time, produced an initial set of 20 indicators, published as Indicators of Sustainability in 1993. The report contained 20 indicators, distributed under the categories of Environment, Population and Resources, Economy, and Culture and Society. Sustainable Seattle, also directly influenced the wording of many policies in the City's general plan, Toward a Sustainable Seattle.

The primary transportation-related indicator was Vehicle Miles Traveled and Fuel Consumption, which registered a slight decrease after decades of continuous increase. 31 This particular indicator had "linkages" to a number of other indicators and conditions, including excessive use of non-renewable resources, pollution, loss of open space and wildlife habitat, decreased social health, and a declining sense of community. The report suggested that improvements could be gained through changing transportation modes (mass transit, walking, bicycling), increased affordable housing near work, and a stable population. Two additional reports were issued in 1995 and again in 1998, representing a total of 40 indicators.

Overall, the indicators suggested that Seattle was not trending toward sustainability. For example, in terms of Vehicle Miles Traveled and Fuel Consumption, the initial decline has been replaced by an increase in miles traveled and fuel consumed. After the 1998 report, this "cutting edge" non-profit organization experienced hard times. However, Sustainable Seattle has since regrouped and formed an alliance with the Cascadia Consultant Group (see www.sustainableseattle.org for more information).

The International Sustainability Indicators Network

Although the evolution of indicators has been modest to date, interest in this tool for sustainability continues to build, as illustrated by the creation of the International Sustainability Indicators Network (ISIN) in 2001. That year, the Rocky Mountain Institute sponsored a workshop entitled, "Indicators of Opportunity: Building Bridges to Policy Change and Action," and invited a small group of individuals with a wide range of experience but a uniform strong interest in the idea. Participants reviewed the current status of indicators, shared success stories, learned about new tools and approaches for applying indicators, and conducted a visioning effort. Out of the workshop, ISIN was born and held another workshop later that year in Massachusetts. An organization was established and a web site created which presents the following statement:

The International Sustainability Indicators Network is a member driven organization that provides people working on sustainability indicators with a method of communicating with and learning from each other. Through listserv discussions, virtual and in-person meetings, and special programs and trainings, the Network facilitates shared learning and development among sustainability indicators practitioners and others (see http://www.sustainabilityindicators.org/). 32

ISIN promotes the use of indicators as a major means to mobilize increased support for sustainability at all scales, "from local neighborhoods to the global economy." ISIN includes an advisory board, staff, and several work groups, including U.S. National Sustainability Indicators, Sprawl/Smart Growth Indicators, Indicators for Decision Making, Business, and Markets and Indicators. For example, the Sprawl/Smart Growth Indicators Work Group has the mission to examine how sustainable development and smart-growth concepts interact by learning about existing tools to measure the comprehensive effects of land-use decisions, and the development of indicators to assist communities to address urban sprawl (web site). The work group is attempting to develop a framework for indicators to monitor land-use management and smart growth, including the connection to transportation planning. A major meeting of ISIN was held in Toronto in March 2003, sponsored by the City of Toronto and Environment Canada.

Conclusions

To date, sustainability indicators have not generated the level of energy found in the new urbanism or smart-growth movements. However, interest in indicators is growing, albeit slowly. As the efforts of organizations such as Redefining Progress and the International Sustainability Indicators Network, among others, evolve, awareness of initiatives of local communities across the globe to develop and implement sustainability indicators will increase. Judith Innes of the University of California at Berkeley argues that effective indicators may require nearly ten years to be adequately established, as quoted by Trudi Lang in her article "Alternative ways to measure progress: How new indicators will impact on road management." 33 Most local community indicator programs are less than 10 years old and have not established an adequate time frame for effective evaluation. In short, more history is needed before STIs can make history.

As the foregoing history indicates, transportation has played a surprisingly minor role in the sustainability indicators movement, and transportation indicators have been few-and- far-between. This is surprising, even astonishing, given transportation's significant and growing impact on all aspects of sustainability.

Whatever the cause, there have been few projects that have attempted to define, measure, and monitor STI. The following section summarizes two pioneering efforts with these aims. The second study, by Canada's Centre for Sustainable Transportation/LeCentre pour le transport durable (CST/CTD), represents the most ambitious and fruitful investigation of STIs in North America to date.

TWO RECENT SUSTAINABLE TRANSPORTATION INDICATOR PROJECTS

Sustainable Transportation: Conceptualization and Performance Measures

Josias Zietsman and Laurence R. Rilett develop sustainable transportation indicators for roadway projects and corridor-level planning in this technically exacting 2002 study. They duly note that there has been little quantitative research and/or implementation of sustainable transportation concepts. The main reasons for this are related to a lack of understanding of sustainable transportation. To address this problem, they develop a comprehensive definition based on Bruntland and compile a set of related performance measures that are typically employed in the evaluation of major transportation project plans. They then devise a framework on how to identify, quantify, and use performance measures for sustainable transportation in the transportation planning process. They test their proposed framework via analysis of the operations and impacts of two Houston, Texas freeway corridors.

Zietsman and Rilett's chosen performance measures (indicators) are conventional, mainly travel time-and its variability, economic costs-and pollution emissions. However, they do demonstrate how to make novel use of Automatic Vehicle Identification (AVI) data and the Transportation Analysis and Simulation System (TRANSIMS) model to obtain travel-related information at highly disaggregate levels. This information is used to quantify sustainable transportation performance measures at the individual level and levels of spatial and temporal disaggregation not previously possible. The AVI data, the TRANSIMS model, and a number of transportation environmental impact models are used to quantify the performance measures at various levels of aggregation.

The authors' performance measures based on disaggregate data can potentially provide richer results as compared to aggregate approaches. Furthermore, Zietsman and Rilett's disaggregate approach can be used to allocate responsibility for negative externalities and to assess sustainability-related impacts experienced by different user groups (e.g. is travel time reliability better or worse for bus riders compared to car drivers?). While focused on motorized travel, Zietsman and Rilett's work represents an important step toward integrating analysis of sustainability factors into the analysis of highway facilities and highway operations.

The CST Sustainable Transportation Performance Indicators (STPI) Project

The Sustainable Transportation Performance Indicator (STPI) Project was completed in December 2002 by the Centre for Sustainable Transportation. It produced a set of indicators that can be used to track progress towards (or away from) sustainable transportation in Canada.

Primary support was provided by Environment Canada and Transport Canada, with additional funding from two other federal departments: Industry Canada-whose stated mission is to foster a growing competitive, knowledge-based Canadian economy-and Natural Resources Canada-a department specializing in the sustainable development and use of natural resources, energy, minerals and metals, forests and earth sciences.

The project was conducted in three phases. Phase 1 was conducted early in 2000 and comprised a review of some relevant activities worldwide and identification of a long list of 84 potential STPI (see Table 3-1). Phase 2, conducted late in 2000, sought to confirm whether or not the project was moving in the right direction, and secured information about potential users of STPI and how the STPI might be used.

Phase 2 was organized around a workshop held in Toronto in November 2000. Two surveys were conducted in preparation for the workshop. One survey sought information from government officials, and others, as to potential users and uses of STPI. The other survey comprised a follow-up of respondents to the two Urban Transportation Indicators surveys initiated by the Urban Transportation Council of the Transportation Association of Canada and conducted during the 1990s. Reports on the surveys are included as two of the Phase 2 report's eight appendices. In short, Phase 2 helped frame Phase 3, which comprised the actual development of STPI.

Phase 3 involved the development of an initial set of 14 STPI. An additional 16 STPI were identified as development possibilities during the next three years, if resources can be made available. Another 14 STPI were identified as being desirable but requiring more than three years for development. The conclusion drawn from application of the initial STPI set is that some progress is being made; however, on balance, transportation in Canada is becoming less sustainable.

Selection and development of the Centre's initial STPI list was based on strict application of the following criteria:

Criterion 1. It should say something about sustainable transportation, as reflected by the CST definition (quoted at the conclusion of the first section of this report). Otherwise it should address one of seven policy questions adapted from the European Environmental Agency. [EEA is a branch of the EU whose Transport and Environment Reporting Mechanism (TERM) program has collected and reported environmentally important transportation indicators for EU member nations since 2000. Unfortunately, for the present study, TERM collects and reports data only at the national level.] Those seven policy questions ask:

Is the performance of the transport sector improving with respect to its adverse impacts on the environment and health?

Are land use urban forms or transportation systems changing to reduce transportation effort?

Are we increasing the efficiency of use of the current infrastructure and changing the infrastructure supply in sustainable ways?

Are patterns of expenditure by governments, businesses, and households (and the associated pricing systems) consistent with moving toward sustainability?

Is technology being used more in ways that make vehicle transportation systems and their utilization more sustainable?

How effectively are environmental management and monitoring tools being used to support policy and decision making toward sustainability?

Is transport activity changing in directions consistent with positive answers to the questions listed above?

Criterion 2. It should be time series data, so that changes in performance could be tracked over time.

Criterion 3. It should represent national (i.e. Canada-wide) information. Unfortunately, this focus means that development of local and regional indicators have been left for later research.

Criterion 4. It should come from a reputable and reliable source-in practice, this usually meant an agency of the Canadian federal government.

The Centre is seeking funds to continue work on the Sustainable Transportation Performance Indicators. Three avenues of future research are envisioned:

To maintain and enhance the initial set of STPI.

To develop some or all of the additional indicators identified for development over the next three years.

To conduct preparatory work for development of the additional indicators identified as requiring more than three years for development.

Although its focus remains at the national level, CST/CTD project represents excellent path-breaking research of great import to the future development of STI. The executive summary of the Phase 3 report is in Appendix A of this study. The entire series of reports may be downloaded from the CST/CTD project website:

http://www.cstctd.org/CSTadobefiles/STPI%20Phase%203%20final%20report.pdf