Florida Center: Transportation, Land Use and Sustainability

GUIDES FOR SUSTAINABLE COMMUNITY DEVELOPMENT
1. Create urban growth boundaries around all metropolitan areas. An urban growth or service boundary is an official, horizontal limit to development. It is characterized by a firm, long-term (20 years) commitment to compact development only within the boundary line and a rigorous process for evaluating any exceptions to the boundary during that time. In many areas, the boundary also serves as the basis for measures to facilitate development within the designated urban area and to channel economic investment to existing major urban centers. Land beyond the boundary is designated for rural or open space use, through exclusive farm use zoning and other means. The main benefits of an urban growth boundary occur as a result of alterations in the locality s growth pattern. By implementing an urban growth boundary, new development and population growth are encouraged to occur through increased density rather than wider sprawl. Growth through increase density rather than sprawl reduces the use of automobiles and leads to decreased pollution and energy consumption. 40 Recognition and acceptance of limits and boundaries are fundamental tenets of sustainable community design: limits on energy, limits on natural resources, boundaries on space and dimension. In many parts of the USA, such restraints are not widely accepted. Within the State of Florida, vast tracts of undeveloped land remain; even with the explosion of growth in recent decades, less than twenty-five percent of the land mass in the State has been developed. The concept that development is always the highest and best use of raw land, however, needs to be relinquished. No development should be thought of extrinsic to its surrounding context, and what might appear to be a desirable development parcel in isolation may prove, in a specific context, to be more socially and environmentally valuable if undeveloped. We need to establish ways to determine, unilaterally, what land should be developed, and what lands should be left open. One of the major obstacles facing sustainable development within the State of Florida is the surplus of developable land. In a capitalist system, anytime there is an over-supply of a product, its apparent value diminishes. Within Florida, this is true of land. A way around this problem is to irrevocably indicate which lands are "available" for development and which are off limits. The easiest, fairest and most comprehensive way to delimit the extent of developable land and to help separate one metropolitan area from another is through Urban Growth Boundaries. Simply defined, an Urban Growth Boundary is "the line on a map that is used to mark the separation of urbanizable land from rural land and within which urban growth should be contained for a period of time specified by a growth management program." 41 Within an defined Urban Growth Boundary, land area is limited. With visible limits on available open space, developable land, and on different types of development, choices for future growth and development become easier. The system will tend, unerringly, towards greater density, greater diversity, greater levels of integration. These, in turn, will help reduce VMT as well as the number of car trips made, and will help make mass transit more functional and more economically viable. Urban Growth Boundaries also take development pressure off of the undeveloped lands outside the boundaries. This helps reduce potential tax burdens on agricultural lands that may have been prematurely zoned for higher intensity uses, and helps balance the ratio of built to unbuilt within a region. On the other hand, Urban Growth Boundaries only work when they are accompanied by a comprehensive growth plan for the region in question. This must discuss transportation and other infrastructure, a jobs/housing balance, affordable housing, and other relevant elements in a regional growth plan. And, it must include provisions for development beyond the edges of the Growth Boundary when an appropriate level of internal development has been reached. The ultimate value of an Urban Growth Boundary, when properly applied, is to "level the development playing field," protect undeveloped lands, especially agricultural lands and environmentally sensitive areas, to help provide a fiscally responsible framework for growth, and to help guide the region in question towards a pre-determined future. Fig 43: Portland's Urban Growth Boundary 2. In new developments, create mixed-use "centers" that include multiple land-uses, higher than average residential densities, and a variety of housing types. To be economically successful, all mass transit systems-especially light rail-require participation, and this is possible only if they link high density suburban regions with high-density central business districts. To make light-rail systems work, cities will have to find a way to increase density at both ends How will cities "densify? " One possibility is to convert empty parking lots produced by the decline in automobile use to office buildings. Although costly, it would be possible to move streets underground creating additional building space. More efficient use of existing office space could help. In many cities, builders could restore abandoned buildings and build on vacant lots that are surprisingly close to urban centers. Efforts to increase population density in suburbs and even some urban neighborhoods are also essential to making large scale mass transit work. One way is to change zoning regulations, allowing families to convert unused living space into apartments. In the case of new developments, builders can maximize density by reducing street widths. building smaller homes, and reducing lawn size . . . New developments should be as self-contained as possible, with shops and store within walking or biking distance. Special walkways or bikeways would connect homes and shops. Builders that concentrated development along major transportation routes-bus routes or new or planned light-rail systems, would make mass transit more convenient. 42 While much new development takes place as "Planned Unit Developments" or "Master planned Communities," usually neither of these design approaches achieves its potential for enhancing diversity, integration and overall sustainability of either the community itself or the region in which it sits. Often, such projects become self-contained "islands" developed at low densities designed for the automobile; in the name of eco-sensitivity, they use profligate amounts of land at relatively low densities, and because such lands can only be found at the periphery of built-up areas, they perpetuate urban sprawl. While communities designed as new towns are not, inherently, unsustainable, their placement with respect to existing development should be such as to complement it, and their internal organization should facilitate diversity and alternatives, particularly with respect to transportation. Such communities should include compact centers that offer a high density of uses including residential, commercial and employment. These centers should be of a walkable size, and should be designed to be pedestrian friendly. New communities should include a diversity of housing types, sizes and forms, and these should be integrated with each other, not separated out into distinct enclaves, that create functional, social and economic division rather than integration. Provisions should be made for a variety of transportation modes such a walking, biking and alternative motor vehicles. Connections outside the new community should include mass transit options, with the mass transit stop located at the mixed-use center(s) within the community.	In essence, what Portland did in the early 1970s was to put a ring around the city beyond which development was not allowed. The intent was to prevent sprawl and to contain development, thus saving the city and its taxpayers the expense of extending electricity, water, sewer lines, and other services beyond the boundary. -- Michael J. Major. "Containing Growth in the Pacific Northwest", Urban Land, March 1994, page 16. The best example of a strong urban growth boundary policy is in metropolitan Portland, OR, where the state land use planning goals for boundaries have been successfully carried out since l972. Many communities have policies that resemble urban growth boundaries but are more accurately described as urban service areas or "Spheres of influence " - that is, flexible boundaries indicating current annexation or infrastructure service plans. -- The Global Cities Project, page 37. Urban growth boundaries (UGBs) should be established at the edge of metropolitan regions to protect significant natural resources and provide separation between existing towns and cities. Lands within the UGBs should be transit accessible, contiguous to existing development, and planned for long-term urbanization Oregon is one of the few states that has enabling legislation for UGBs. -- Peter Calthorpe. The Next American Metropolis, page 73.

GUIDES FOR SUSTAINABLE COMMUNITY DEVELOPMENT

1. Create urban growth boundaries around all metropolitan areas.

An urban growth or service boundary is an official, horizontal limit to development. It is characterized by a firm, long-term (20 years) commitment to compact development only within the boundary line and a rigorous process for evaluating any exceptions to the boundary during that time. In many areas, the boundary also serves as the basis for measures to facilitate development within the designated urban area and to channel economic investment to existing major urban centers. Land beyond the boundary is designated for rural or open space use, through exclusive farm use zoning and other means.

The main benefits of an urban growth boundary occur as a result of alterations in the locality s growth pattern. By implementing an urban growth boundary, new development and population growth are encouraged to occur through increased density rather than wider sprawl. Growth through increase density rather than sprawl reduces the use of automobiles and leads to decreased pollution and energy consumption. 40

Recognition and acceptance of limits and boundaries are fundamental tenets of sustainable community design: limits on energy, limits on natural resources, boundaries on space and dimension. In many parts of the USA, such restraints are not widely accepted. Within the State of Florida, vast tracts of undeveloped land remain; even with the explosion of growth in recent decades, less than twenty-five percent of the land mass in the State has been developed. The concept that development is always the highest and best use of raw land, however, needs to be relinquished. No development should be thought of extrinsic to its surrounding context, and what might appear to be a desirable development parcel in isolation may prove, in a specific context, to be more socially and environmentally valuable if undeveloped. We need to establish ways to determine, unilaterally, what land should be developed, and what lands should be left open.

One of the major obstacles facing sustainable development within the State of Florida is the surplus of developable land. In a capitalist system, anytime there is an over-supply of a product, its apparent value diminishes. Within Florida, this is true of land. A way around this problem is to irrevocably indicate which lands are "available" for development and which are off limits. The easiest, fairest and most comprehensive way to delimit the extent of developable land and to help separate one metropolitan area from another is through Urban Growth Boundaries.

Simply defined, an Urban Growth Boundary is "the line on a map that is used to mark the separation of urbanizable land from rural land and within which urban growth should be contained for a period of time specified by a growth management program." 41 Within an defined Urban Growth Boundary, land area is limited. With visible limits on available open space, developable land, and on different types of development, choices for future growth and development become easier. The system will tend, unerringly, towards greater density, greater diversity, greater levels of integration. These, in turn, will help reduce VMT as well as the number of car trips made, and will help make mass transit more functional and more economically viable.

Urban Growth Boundaries also take development pressure off of the undeveloped lands outside the boundaries. This helps reduce potential tax burdens on agricultural lands that may have been prematurely zoned for higher intensity uses, and helps balance the ratio of built to unbuilt within a region. On the other hand, Urban Growth Boundaries only work when they are accompanied by a comprehensive growth plan for the region in question. This must discuss transportation and other infrastructure, a jobs/housing balance, affordable housing, and other relevant elements in a regional growth plan. And, it must include provisions for development beyond the edges of the Growth Boundary when an appropriate level of internal development has been reached. The ultimate value of an Urban Growth Boundary, when properly applied, is to "level the development playing field," protect undeveloped lands, especially agricultural lands and environmentally sensitive areas, to help provide a fiscally responsible framework for growth, and to help guide the region in question towards a pre-determined future.

Fig 43: Portland's Urban Growth Boundary

2. In new developments, create mixed-use "centers" that include multiple land-uses, higher than average residential densities, and a variety of housing types.

To be economically successful, all mass transit systems-especially light rail-require participation, and this is possible only if they link high density suburban regions with high-density central business districts. To make light-rail systems work, cities will have to find a way to increase density at both ends

How will cities "densify? " One possibility is to convert empty parking lots produced by the decline in automobile use to office buildings. Although costly, it would be possible to move streets underground creating additional building space. More efficient use of existing office space could help. In many cities, builders could restore abandoned buildings and build on vacant lots that are surprisingly close to urban centers.

Efforts to increase population density in suburbs and even some urban neighborhoods are also essential to making large scale mass transit work. One way is to change zoning regulations, allowing families to convert unused living space into apartments.

In the case of new developments, builders can maximize density by reducing street widths. building smaller homes, and reducing lawn size . . .

New developments should be as self-contained as possible, with shops and store within walking or biking distance. Special walkways or bikeways would connect homes and shops. Builders that concentrated development along major transportation routes-bus routes or new or planned light-rail systems, would make mass transit more convenient. 42

While much new development takes place as "Planned Unit Developments" or "Master planned Communities," usually neither of these design approaches achieves its potential for enhancing diversity, integration and overall sustainability of either the community itself or the region in which it sits. Often, such projects become self-contained "islands" developed at low densities designed for the automobile; in the name of eco-sensitivity, they use profligate amounts of land at relatively low densities, and because such lands can only be found at the periphery of built-up areas, they perpetuate urban sprawl.

While communities designed as new towns are not, inherently, unsustainable, their placement with respect to existing development should be such as to complement it, and their internal organization should facilitate diversity and alternatives, particularly with respect to transportation. Such communities should include compact centers that offer a high density of uses including residential, commercial and employment. These centers should be of a walkable size, and should be designed to be pedestrian friendly. New communities should include a diversity of housing types, sizes and forms, and these should be integrated with each other, not separated out into distinct enclaves, that create functional, social and economic division rather than integration. Provisions should be made for a variety of transportation modes such a walking, biking and alternative motor vehicles. Connections outside the new community should include mass transit options, with the mass transit stop located at the mixed-use center(s) within the community.

In essence, what Portland did in the early 1970s was to put a ring around the city beyond which development was not allowed. The intent was to prevent sprawl and to contain development, thus saving the city and its taxpayers the expense of extending electricity, water, sewer lines, and other services beyond the boundary.

-- Michael J. Major. "Containing Growth in the Pacific Northwest", Urban Land, March 1994, page 16.

The best example of a strong urban growth boundary policy is in metropolitan Portland, OR, where the state land use planning goals for boundaries have been successfully carried out since l972. Many communities have policies that resemble urban growth boundaries but are more accurately described as urban service areas or "Spheres of influence " - that is, flexible boundaries indicating current annexation or infrastructure service plans.

-- The Global Cities Project, page 37.

Urban growth boundaries (UGBs) should be established at the edge of metropolitan regions to protect significant natural resources and provide separation between existing towns and cities. Lands within the UGBs should be transit accessible, contiguous to existing development, and planned for long-term urbanization Oregon is one of the few states that has enabling legislation for UGBs. -- Peter Calthorpe. The Next American Metropolis, page 73.

3. Use mass transit systems as a development guide, both to provide alternatives to the automobile and to link high density commercial and residential centers.

Almost every theory of sustainable community design hinges to a greater or lesser degree on mass transit as a key transportation alternative. Mass transit is, inherently, more environmentally benign and more energy-efficient than systems based on the use of personal automobile, and the most comprehensive sustainable community design theories are, in fact, developed around mass transit system. Of these concepts, the Transit Oriented Design approach, developed and promoted by Peter Calthorpe from California, is the most comprehensive. Calthorpe bases his designs on a refined mixture of a European-style transit system and the traditional American small town; in essence, he proposes a sophisticated version of the "street-car suburb."

In Calthorpe's approach, which was developed initially to meet conditions found in California, Oregon and Washington state, new use is made of existing rail lines, many of which had been abandoned after World War II. Using these trunk lines as feeders to connect neighborhoods to dominant regional centers --such as a metropolitan downtown-- he suggests that compact, high-density "nodes" be built at intervals along the lines, with the transit stations serving as the "center" of town. The "Transit Oriented Developments" (TODs) include a core area of about quarter-mile radius, and a secondary area that extends an additional quarter mile out. Within this bounded area, development occurs at a full range of densities, with attention to creating an easily accessible town center at the transit hub. Calthorpe sees the development and the transit line as complementary. The line provides easy accessibility to a particular set of destinations, the TODs become both destinations in their own rights and suppliers for larger regional destinations. And, because such transit lines often run through areas of low-level pre-existing development, they can be used to spur re-development of these areas.

4. Rejuvenate older, under-utilized pre-existing core areas into compact, high-density, mixed-use urban neighborhoods.

Throughout the country there is an impulse to go back to denser living spaces, to revive Main Street, to shape true communities with walking centers for the young, the elderly and all the rest of us, as they were before World War 11. Shrinking streets would release 30 to 60 percent of our cities given over to the auto, as Richard Register has pointed out in Eco-city Berkeley; this diagram for tomorrow, in which building compactly saves fossil fuels, supplies the population density for mass transit and encourages community, is becoming a starting point for other urban builders, too 43

Nearly every major metropolitan area in the United States has regions within its boundaries that are under-populated and underdeveloped. These older, under-developed urban centers should be viewed as embodied energy rather than as blight. While the buildings or land within these areas may no longer meet the needs and uses for which they were originally planned, they represent enormous potential to become new communities or neighborhoods at costs that are considerably cheaper (using both internal and external cost factors) and less environmentally damaging than building on virgin sites. Typically, all or most of the necessary infrastructure is already in place and the land in undervalued; usually, these areas are proximate to areas with high concentrations of businesses and/or established neighborhoods. Re-developed, these areas can complement and supplement this pre-existing development.

Many advocates of sustainable design believe that there is enough under-developed land within existing cities and regions to more than cover all potential future growth for years to come. Mechanisms must be established that make visible the "true" savings of developing these areas; these mechanisms include elements such as Urban Growth Boundaries and the re-development of mass transit, but further incentives in the form of tax benefits, fee waivers, low- or no-interest loans and the like can also make the re-development of these areas financially profitable. Figuring out ways to make the capitalist economy recognize the embodied potential of these previously vital areas is one of the major challenges for our cities and regions in the upcoming decades.

5. Use mixed-use developments to provide focus within existing lower-density and undifferentiated residential developments; make these centers part of the mass transit system.

Mixed use developments, as single projects, help provide definition and focus within today's typically sprawling communities; they can be treated as a form of "instant downtown." They create variety and diversity within the homogenous landscape of sprawl, and often serve as incentive for additional medium- and high-density developments. Mixed use projects are, by definition, pedestrian in scale. Thus, they can reduce dependence on the personal car and create greater opportunity for interaction of diverse uses and users. Internal interaction, however, must be complemented by external connectivity. Mixed-use projects should not be developed as islands unto themselves, but should be well integrated into the surrounding built context; there should be a variety of routes and means for approaching the project: car, bike, foot, mass transit.

Ideally, these mixed-use project should be developed as part of a functional mass transit system. This immediately broadens the projects "catchment area" and makes further intensity of uses possible because of reduced need for parking spaces. As the example of the Lenox district in Atlanta shows, there is a positive symbiosis between effective mass transit systems and successful mixed use activity centers. These areas become the distinctive "high points" in an otherwise undifferentiated suburban landscape

Fig. 44: Mizner Park, Boca Raton, Florida

6. Use Traditional Neighborhood Planning principles in designing new neighborhoods and residential areas.

At the heart of the neotraditional movement is the objective of re turning to the kind of communities in which the automobile does not reign supreme, and in which residents and workers can realistically walk or tricycle to work, school, or shopping. 44

To some degree, Traditional Neighborhood Planning treats entire neighborhoods as large mixed-use projects, albeit without the dominant focus on commercial and retail uses. It is a fundamental tenet of Traditional Neighborhood Planning that the size and design of the community reflect an emphasis on pedestrianism; the entire project should not be so large that any one point in the project is more than a twenty minute walk from any other point. The project should also contain design features such as wide, shaded sidewalks, arcades, protection from cars and appealing views in order to promote walking.

A second tenet of Traditional Neighborhood Planning is diversity of uses and functions. Thus every neighborhood should include shopping and work opportunities in addition to a variety of housing types and costs. Because a ten-minute walking radius of necessity inscribes a relatively small overall area (approximately 400 acres), the density of residential development must be high enough to economically justify a range of work and shopping uses. These uses should be given further promotion by clustering them at the center of the development where they are equally accessible to all residents, and potentially accessible to users from outside the neighborhood. As with Transit Oriented Developments, the compact size and structure of "neo-traditional" neighborhoods, combined with its diversity, makes them ideal targets for mass transit systems.

Just as neighborhoods should be specifically bounded and delimited in size and scope, so too, the spaces between neighborhoods should be designed to support specific functions and needs and to complement the development within the neighborhoods themselves. In some instances, these areas should be used to preserve environmentally sensitive lands such as watersheds, wetlands, estuaries, and so forth. In other instances, the land should be designed as functional open space containing elements such as bike-trails, greenways, bridal paths, parks, forests, farms, pastures, etc. In certain instances, these open spaces can be used to support transportation systems; the road in the park, such as is found in the parkways designed by Robert Moses in and around New York City, or to buffer stretches of train tracks in-between transit stops.

7. Avoid continuous commercial zoning along arterials; instead, create pedestrian-friendly commercial clusters in easily accessible locations.

One of the paradoxes of today's auto-oriented commercial strip development is how often it creates conditions in which pedestrians literally "can't get there from here." A six- or eight-lane divided arterial road with commercial structures on either side set back behind several hundred feet of parking is as uninviting an environment for pedestrians as can be found. Thus, this very conventional and common development form forces people to use their cars to travel relatively short distances both along and across the strip. Because these trips are often less than a mile in length and require a great many car starts, they contribute inordinately to air pollution in a particular location.

Re-thinking the design of commercial zones and re-developing existing commercial corridors into more functional and humane environments are key elements of creating sustainable communities in the future. Current commercial strips often run continuously for five miles or more. These should be broken into smaller increments of intense commercial development separated by non-commercial uses. By upzoning the commercial nodes and down-zoning the spaces in between, a more variegated and diverse arterial develops, one that has a number of pre-determined focal points rather than a continuous barrage of low-level destinations. These nodes of commercial development, in turn, should be designed to be pedestrian friendly and internally walkable; getting t the developments can occur by car, bike or mass transit; getting around within the development should take place on foot. And, the overall commercial potential of a region remains approximately the same; instead of the low-level uses currently found (0.2 FAR and less), commercial development makes optimal use of less land area, allowing alternative uses greater accessibility-multifamily residential, open space, parks, institutions, etc.

8. Institute a system for the transfer or marketing of development rights.

In the United States, there is constant pressure at the fringes of developed areas to convert open land into further development. While urban growth boundaries and the use of greenbelts are devices that help insure a constant supply of stable open land for a variety of uses, additional, legal measures are often warranted. One of the most effective of these is the concept of Marketable Development Rights. Within the concept, every piece of open land has an assessed development value that complements its function as open land. Thus, an active farm might have the development potential of one unit for every five acres of land. If the farm is 1,000 acres in size, its total development potential is 200 units. While it is desirable that the farmland remain as agriculture, under current situations, the farmer will be inexorably pressured to seek upzoning and then sell off the land for development. Under the concept of marketable development rights, the farmer would not be able to seek up-zoning, but would be able to sell (or "market") the farm's current potential to hold 200 units of housing, but only to someone who would look to develop the housing elsewhere.

Thus, if someone has a five-hundred acre parcel that has been authorized for 1,000 units of housing, but wishes to enhance the density of the parcel, this person could purchase an additional 200 units of potential from the farmer. This would render the farmland forever depleted of development potential, leaving agriculture as its highest and best use, in perpetuity, and would enable an "in-town" developer to create a denser, and in terms of sustainability, "more desirable" development.

9. In all transportation planning, provide a balanced mix and integration of transportation modes, with special emphasis on bicycles and pedestrians.

The convenience of the car and the opportunity to walk or use transit can be blended in an environment with local access for all the daily needs of a diverse community. It is a strategy that could preserve open space, support transit, reduce auto traffic, and create affordable neighborhoods. 45

The goal of community planning for the pedestrian or transit is not to eliminate the car, but to balance it. 46

The concept of "sustainable transportation " calls for a more holistic approach to policy and investment planning to achieve a diverse and balanced mix of transport modes and a sensible arrangement of land use that enables conservative use of energy and capital to fulfill mobility needs. Sustainable transportation strategies are those that can meet the basic mobility needs of all and be sustained into the foreseeable future without destruction of the local or planetary resource base. 47

Sustainable community design attempts, as much as possible, to bring diverse uses as close together as practical. This enables a great many of the ordinary interactions of everyday life to occur via an efficient energy form, at relatively little energy expenditure. Such interactions include trips to stores, dry cleaners, schools, church, etc. On the other hand, many trips in today's society are not exchangeable; one cannot, for example, select where one's place of employment is, and if one selects a residence to be close to one's job, one's spouse may find his or her job to be inconveniently distant. To the degree that trips can be excluded, minimized, or ganged together, this should be promoted. Where long trips are necessary, however, efficient alternative forms of transportation should be available. If one's home to work to home commute is relatively fixed, bus, train, carpool or some other form of group transportation is more energy efficient that the private automobile.

Obviously a mass transit system, even in its simplest form, represents an enormous undertaking both in terms of money and time. Other measures are available that require less money and are easily instituted and adopted. These include organized carpooling and vanpooling, transportation demand management, flex-time work hours that enable people to travel when and if they need to in order to accomplish their work, telecommuting, striped bike lanes, specific 'bike to work" days and programs, showers and lockers located within work places, and many others. Prices can be attached to employee and shopper parking spaces, and monetary incentives can be given to employees or shoppers who use mass transit

Streets can be made safer for both pedestrians and bicyclists through a full range of traffic calming devices including speed bumps, humps and tables, chicanes, roundabouts, raised walkways, pavement changes and the like. Many of these can be instituted as part of regular maintenance on existing streets. In addition, streets can be made more pleasant environments for pedestrians and bicyclists through the use of sidewalks, landscaping, street trees and the introduction of distinctive uses such as small parks and civic spaces, localized shopping areas and natural features.

10. Encourage telecommuting and the infrastructure necessary to make it work.

Currently, less than 5&degree;/O of the American work force works full-time at home, and it is likely that this number will not rise very much. The nature of our economy is such that some level of face-to-face interaction is still necessary for the vast majority of jobs, and to a greater or lesser degree, most workers enjoy some level of social interaction while at work. Thus, even if a person's job could be structured so that all work could be done at home, using fax, phone and modem for "communication," the odds are very high that they person would not choose to spend all of his or her time working our the house.

On the other hand, a great many people do have the capacity to spend some of their work week away from the office, and to the degree that some amount of the average work week can be done without recourse to a car trip, telecommuting should be encouraged. If every worker spend one day a week working at home, traffic would be reduced by 20% during the week. This minor change, which many employees and employers would find desirable, would have enormous impact on air pollution, traffic congestion, and gasoline usage. (The four-day work week, which encompasses 40 hours of work into one less day, similarly helps reduce traffic and provides workers with increased leisure opportunities.)

In other instances, large employers might choose to develop satellite offices throughout a community or region. Rather than reporting to the Headquarters which would entail a thirty-mile drive, an employee could check in at a branch office which is within walking or biking distance. "Office condominiums" are another aspect of telecommuting that are beginning to spring up across the country: well-located facilities that include access to desks, telephones, computers, copiers, secretaries and the like, which can be rented by the hour, day or week. They are not associated with any one company, and can be used by anyone who needs the facilities.

While telecommuting currently represents only a small percentage of the work force, and it is unlikely that it will ever become the dominant characteristic of American employment, it does have the potential to contribute not only to resource conservation and overall sustainability, but also to employee satisfaction and productivity.

A traditional neighborhood development is a place with characteristics that prevailed when walking and transit were the primary means of getting around. The premise of using TND as a model for modern urban planning is that they would still be well suited for walking and transit. Their transportation-related features are in stark contrast with Conventional Suburban Developments (CSDs). The streets are narrower The blocks are smaller The streets are in grids that are more or less continuous. There is parking on the streets. There are alleys for vehicle access, so autos needn 't cross sidewalks. Front yards are shallow, and lots are narrow. There is mixing of land uses.

-- Bob Walter, Lois Arkin and Richard Crenshaw. Sustainable Cities - Concepts & Strategies for Eco-City Development, page 168.

Although in the United States the term greenbelt conveys any relatively wide swath of open land (and in some areas is used interchangeably with greenway), in Britain, where the concept originated around the turn of the century, the greenbelt has the quite particular function of separating communities to preclude "conurbation", as Lewis Mumford points out in The City in History. Mumford cites British economist Alfred Marshall, who made the point this way in an 1899 paper: "We need to prevent one town from growing into another, " Marshall wrote, "or into a neighboring village; we need to keep intermediate stretches of country in dairyfarms, etc., as well as public pleasure grounds.

-- Charles Little. Greenways for America, page 15.

The woonerfs are perhaps the best examples of pedestrian friendly street treatments. In a woonerf, the street is shared by vehicles and pedestrians, with clear indications to drivers that they are on pedestrian turf and have to behave accordingly.

-- Bob Walter, Lois Arkin and Richard Crenshaw. Sustainable Cities - Concepts & Strategies for Eco-City Development, page 173.

Specifically, we must create effective public transportation options that enable a substantial number of current and prospective motor vehicles users to shift their mode of travel to means that do not add to bumper-to-bumper jams on roads. Buses and vans are certainly more load-efficient passenger carriers than autos.

-- Jarold A. Kieffer. "What Are We Going To Do About Public Transportation?", Journal of Advanced Transportation, 22, no. 2, 1988, page 97

Ecological systems are healthiest when they display great species diversity and many niches for specialization of function and resource utilization. So too are transportation systems healthiest when they display great modal diversity, offering opportunity for selection of the most efficient mode or combination of modes to meet different functional and qualitative demands for movement of people or goods.

-- Michael Replogle. "Sustainability: A Vital Concept for Transportation Planning & Development," Journal of Advanced Transportation, 25, no. 1, page 6.

CONCLUSION

Sustainability is not a magic bullet that can be taken once. It is not a single tool or design feature. It is not a short-term vision. Rather, it is a long-range philosophy towards the design, construction, use and maintenance of the built environment that attempts to rectify some of the more serious transgression of contemporary development practices.

Fundamental changes must take place in the areas of land-use planning and transportation planning, and the two are inextricably linked. While there is an enormous amount of land available within the United States, attempting to make vast tracts of it equally accessible to all people is environmentally wasteful and energy inefficient. It is also unnecessary.

The majority of future developments must be denser than today's standards. While it is possible to create densities on the level of New York City, Paris, or even Hong Kong, these are not necessary. Rather, a more widespread use of moderate densities such as can be found today in many communities throughout the country will greatly facilitate the goals of sustainability. With development densities of 12 to 20 units per net acre, organized into distinct nodes, mass transit not only becomes cost effective, it becomes desirable. At these densities, enough activities can be compressed into a location as to put all the elements of daily living within easy walking distance. Nor do these densities imply enormous changes from current residential types or conventional construction. One often finds successful suburban single-family residential projects at densities of up to 10 units per net acre. Townhouses with attached garages and yards can comfortably reach densities of 20 units per acre, while garden apartments and condominiums with surface parking often exceed 25 dwelling units per acre. None of these building types has to be over three stories in height.

Design will take on increasing importance, with a distinct focus on quality over quantity. Densities are not only tolerable but can be desirable when buildings are well designed to insure privacy and provide amenities such as views, natural lighting, and ample interior space. And, increased density within a mixed-use framework can help make housing costs more affordable for the majority of consumers. Bicycles and other non-automobile forms of transportation will need to be carefully integrated into systems that are currently geared only to the needs' characteristics and dimensions of the car. These modes are all smaller, more energy efficient and more environmentally benign than the personal automobile, and just as effective, particularly for short distances.

Vertical mixing of uses will enable further integration of land-uses, and further diminish the need for automobile trips, particularly short ones, which are the most energy-consumptive and polluting. New communication technologies can further diminish the need for redundant, short car trips. The drive to work may be replaced by the walk downstairs, and the trip to the shopping center may be replaced by a phone call.

Mass transit systems will be seen as design and development opportunities rather than as merely mobility options. The concept of "lifestyle corridors" will take on increasing importance, as mass transit systems will be geared towards particular demographic sectors, and land-use, transportation planning and building design will be totally integrated

Sustainability implies dramatic changes in and challenges to the way we currently plan, design and construct our communities. It offers opportunities to create communities that are, at once, more environmentally responsible and offer more personal freedoms. Fundamental to this goal are changes in the way we view and design transportation systems. We must return to an understanding of transportation as a means of providing the most efficient movement of people, goods and information from one point to another, and we must develop a holistic sense of the term "efficient."

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