Complex-city in its Contradictions

By Marina Christodoulides, M.Arch, and M.C.P. Student

It all began on January 7, 2007, in the haze of the San Francisco night lights, when UC Berkeley students checked in at SFO airport for a flight to Delhi, India.

10“Who is working for Nano City? Is he? Is she?” I thought to myself as I filed into the aircraft — the suspense and excitement building as we funneled into the tight space. I could not begin to fathom what was in store for me and my fellow classmates. I can now say that the excitement and enthusiasm never curbed, that the surprises and curve balls never ceased and the characters involved were rich with idiosyncrasies, making the journey a tumultuous, boisterous affair that culminated into one of my most enriching academic experiences.

The majority of our weeklong stay in India was spent in transit inside a big red Volvo bus, fusing camaraderie between our client, Sabeer Bhatia, and his group, the faculty leading and accompanying the studio, and other UC Berkeley students. As this was my first trip to India, I became mesmerized by the world outside the window. The streets were a continuous spectacle of the hustle and bustle of Indian life. Motor rickshaws, cows, monkeys, bicycles, squatters, villagers, men playing cards, shaving, defecating, cooking, carrying cargo — a bazaar of private life paraded across the stage of the public sphere. The images blasted in front of me like a blaring television screen, consuming my attention and senses even though my physical self remained protected by the now familiar interior of the red Volvo bus. This panorama of sights and sounds was occasionally interrupted with breaks for the restroom and meals, meetings with the Governor of Haryana and its ministers, an intense conversation with the villagers living on the site, and nights spent in the comfort of five-star hotels.

On one hand, the trip to India was a complete whirlwind; on the other, the perspective we gained was a mere Cliff’s notes introduction to our site and its larger context. However, it whetted our appetite for future work and upon our return to Berkeley, we immediately began design work for Nano City while simultaneously taking Professor Nezar AlSayyad’s course on housing and urbanization in the Third World.

So began the challenge of the semester. As we became increasingly educated about issues of housing in different parts of the world, our design required further development. The contradiction of designing a private city with growing awareness toward issues of informality and housing could not slow us down from every impending deadline. And while theory could not be espoused without a design implication, design could not occur in a vacuum of ignorance. There was a constant tug-of-war between our conceptual knowledge and our practical design solutions.

The complexity of the project did not end there. The studio was composed of two eight-person groups that were each commissioned to design a master plan. And while working in groups and for a real client is quite foreign to the traditional architectural studio, it put us in a scenario that was much closer to professional practice. In the end, the product was much richer than anything we could have done as individuals. By continuously learning from each other, and building on each other’s strengths, the final studio product reached an admirable level of resolution.The Nano City Super Studio pushed and pulled at the boundaries of academic theory and practice, of individuals and teamwork, of disciplinary boundaries such as architecture, city planning, landscape and urban design. Through continuous struggle, friction and contradicting demands, we found our home in the complex beauty of the Nano City project.



Transnational Connection| The Nano City Super Studio, India

Innovative projects often have unusual beginnings.

9In Fall 2006, I received an e-mail from an individual who informed me that he was planning a new city in India. He wanted to meet me to discuss what ideas I may have for such a project. A new city that would be privately built — indeed, the idea made me wonder! Fortunately, my initial instinct to delete the e-mail and to dismiss the idea altogether did not prevail and I agreed to a short meeting with its sender in my office the following week. On the day of the meeting and after a brief Google search, I discovered that I was about to meet Sabeer Bhatia — the co-founder of Hotmail, and one of India’s if not the world’s, most recognized young entrepreneurs.

Bhatia, a graduate of Stanford University, had come to us in Berkeley seeking our expertise to realize his vision for Nano City — a new, sustainable, eco-friendly, and high-tech city in north India. The 11,000 acre site earmarked for the project is nestled in the foothills of the Himalayas and within close proximity of the city of Chandigarh in the state of Haryana. By all measure, Bhatia is a dream client: a young visionary whose education and ambition are matched with a social conscience. Having co-founded Hotmail in the 1990s and subsequently selling the corporation for $400 million to Microsoft, he went on to establish other IT companies and develop social ventures beyond technology. Although he came to us mainly for advice about how to pursue his new project, it quickly became clear that his engagement with us was not going to be a passing one.

8Stemming from my conviction that successful projects are a product of a close collaboration between an educated client, a competent designer, and an informed public, I convinced Bhatia that we should pursue the project as a college-wide graduate urban design studio, involving a group of faculty from different specialties. Having now become our client, Bhatia also generously funded the studio which included a site visit by 16 students and 6 faculty members for a 9-day trip to India. While in India, the design team also met with government officials in the state of Haryana and other developers collaborating on the project.

The CED has had a long tradition of conducting Super Studios, which are intense design collaborations for a semester-long project and involving several faculty as supervisors. The tradition harks back to studios conducted by Lars Lerup and Stanley Saitowitz in the 1980s as well as those by Mark Mack, Richard Fernau, and myself in the 1990s. It was indeed time to revive this tradition with the Nano City Super Studio. My enthusiasm for the project as well as that of the students was shared by committed CED faculty such as my colleague Professor Susan Ubbelhode — an expert on the architecture of Chandigarh and frequent visitor to India — who agreed to co-teach this studio. Richard Fernau cut his sabbatical short and participated as a studio critic. Robert Cervero, Chair of the DCRP; Chris Benton, former Chair of Architecture; and Ananya Roy, Professor of City Planning and Associate Dean of International and Area Studies, all agreed to serve as studio consultants by delivering lectures on design and planning policy and by participating in all studio presentations.

When we advertised the studio in late Fall as a joint Architecture, City Planning, and Urban Design course we were inundated with applications from students. Since this was a truly interdisciplinary studio, open to students from the whole college, we selected 16 applicants from the M. Arch, M.C.P., M.L.A., M.U.D., and the PhD programs in Architecture, City Planning, and Landscape Architecture.

Our visit to India was an intense experience yet memorable too. We traveled between Chandigarh, the foothills of the Himalayas, and the urban outskirts of Delhi. On a visit to the proposed project site, Berkeley students demonstrated what it means to immerse oneself in the context that they design for. Refusing to simply travel in the confines of an air-conditioned bus or meet government officials, the group visited a few of the villages on the site and spent a session meeting with and interviewing villagers whose fate would be impacted by the project.

From its onset, the studio emphasized both collaborative effort as well as teamwork in the design process. On our return to Berkeley, students were assigned to teams who then delegated individual tasks to each member. Interdisciplinary methodologies were pursued by addressing the multiple scales of design involved in a project of this nature. The studio started with a week-long intense charette where each student produced a master plan. Following the charette the students were broken down into 8 teams and continued to work in pairs for 3 weeks to produce land-use and master plan solutions. This was followed by an intense 5 week session where 4 teams — each made up of 4 students — focused solely on urban design. Finally, the students were divided into 2 teams, each pursuing alternative master plans and also articulating an architectural strategy of which one was selected as a final master

The final design solution for Nano City proposes a three-phase development model which will ultimately include a small educational sector with campuses of major U.S. universities; a business development sector with headquarters of several technology firms (providing biotechnology, informational technology, and nano services); a major housing development of up to 50,000 small, medium, and large size units; and appropriate commercial and recreational services in order to generate a vibrant mixed-use

The end of the semester may have been an ending to the Nano City Super Studio but today the project continues. Nano City Inc. has accepted the general master plan generated by the studio and has officially hired 10 other Berkeley students to further develop it into a more detailed urban design, under the supervision of a few faculty members. The final master plan of Nano City designed by what is now called B-GAP — the Berkeley Group for Architecture and Planning — will be formally unveiled early in the Fall. It stands as a testament not only to the possibilities of collaboration between the different disciplines within the CED but also to the successful collaboration between clients and designers. Indeed, the Nano City Super Studio attests to the creative potential of a paradigm that believes that political position and social responsibility can deliver design excellence. As we continue with design and development, we look forward to the moment when Nano City will break ground in 2009.

For additional information about the Nano City Super Studio please visit:

Global Engagements: Teaching Transnationally

The College of Environmental Design (CED) has a long tradition of engaging in various ways with the world at large. Indeed, it can boast some of the world’s top experts on Latin America, the Middle East, and South Asia amongst its faculty members. The expertise of our faculty members also represents the diverse panorama of environmental design and is evidenced by CED’s proficiency in many fields ranging from housing to urbanization and from urban design to infrastructure planning. Courses in the College’s three departments clearly illustrate this international and interdisciplinary outlook and while design studios conducted abroad and structured around the problems of other countries are not new, they have taken on a new dimension as well as a new urgency at this moment as this issue of Frameworks illustrates.

Globalization and the rise of the information society have redefined the landscape of both professional knowledge and practice. But while such trends may have resulted in homogenization to some degree, they have also offered the possibilities of recognizing the international and cross-cultural potential of local and regional traditions particularly as they relate to the developing countries of the so-called “Third World.” One may argue that we are embarking on a new stage in the relationships between the First and the Third Worlds, one that may depart from the long and brutal legacies of colonialism. Many Third World countries in the global South, like China, India, and Mexico are now witnessing unprecedented rates of urban development and economic growth. Often these changes have been coupled with transnational alliances and aggressive policies that help countries position themselves globally and in ways that have allowed some of them to rapidly join the advanced or industrialized nations of the First World. From our vantage point today, it appears that the latest wrinkle in the old international division of labor, previously characterized by the flow of information from South to North and its return in the form of manufactured products in the 20th century, has been replaced with the flow of information from North to South and its return in the form of outsourced knowledge and specialized immigrant labor. And while it is too soon to cheer the demise of colonial structures of surplus extraction or labor exploitation, we may also recognize that these have been fundamentally recalibrated allowing the global South to shape the prospects of the North just as the latter continues to study and practice within the former.

I believe that a truly global approach to teaching architecture and planning in this transnational world must be based on two separate yet linked educational beliefs. The first is the belief that the study of other people, cultures, and environments is an obligation that should be pursued with the conviction that such knowledge is necessary for our own well-being as well as that of others. An exchange between various cultures and or countries when pursued on this premise often brings mutually beneficial by-products. For example, many traditional environments in the Third World offer innovative solutions and practical insights regarding the complexity of the social environment — knowledge that is crucial to contemporary practice. Learning from such places and practices allows us to situate ourselves in the wider human context — which one may argue is the very essence of our profession and discipline.

The second belief underlying this approach stems from the conviction that we in the First World have an ethical responsibility to play a role in the development of the Third World, possibly reversing the decades of intellectual hegemony that accompanied centuries of colonization. Training practitioners in areas like managing urbanization and providing infrastructure in which the First World has been generally successful is no longer a luxury but in fact a necessity. For we must accept that as one of the premier public institutions in the First World, we are also part of a Berkeley “tradition” that reminds us that the circumstances of the Third World are neither irrelevant nor marginal to the well-being and continued strength of the First World.

In the pages that follow, you the reader, will learn about the various ways in which the CED has carried forward its own epistemological traditions as well as those of the Berkeley campus at large. As the guest-editor of this issue of Frameworks, I hope that this magazine will stand for more than just a catalog of CED’s accomplishments in the past year. That the various global studios conducted by the College will be understood as more than simply a means to gain professional skill or license. Mostly, I hope that our efforts at transnational teaching will help us recognize that we need to learn more about the world and our place within it, while also recognizing our professional limitations and our complicity in the current state of global affairs.

Learning From Experience

Ask anyone who designs, owns, or manages an office building if they want the occupants of their building to feel comfortable, healthy, and productive, and the answer would of course be ‘yes’.   But ask again if they know what the occupants actually feel about the space, and the answer will be quite different.

Photo_Carnegie_rainbowThe facility manager is most likely to have a sense, but often it’s only anecdotal. The building owner might eventually have an inkling about occupant sentiment if they see a financial effect because an environment is inadequate. Yet, sadly, very few architects or other members of the design team are likely to know how well their building is working after it is completed and occupied, the fees have been paid, and they are on to another project. Without learning from experience in an objective way, building industry professionals are less likely to make design or economic decisions that will truly enhance the performance and experiential quality of their buildings.

And while this information would be valuable for any project, it is particularly essential if one is claiming to have designed or built a green building, where the quality of the indoor environment is a critical dimension of sustainable design. The only way to back up those claims is to evaluate a building’s actual performance, in terms of energy consumption or indoor environmental quality, and compare the performance to design intent.

Without question, it is absolutely crucial to reduce energy consumption in buildings and help avoid the potentially devastating impacts of climate change. But in terms of the building owner’s pocketbook, energy costs are still relatively small compared to worker salaries, which represent over 90% of the total operating costs of a commercial building. In addition, the cost of worker recruitment and retention is significant. Thus, from the building or company owner’s point of view, perhaps the most persuasive argument for sustainable design is one that makes the connection between a higher quality indoor environment, and increased comfort, health and productivity of the workers.

So, how does one learn about the quality of the indoor environment? While there are many physical measurements one can take, they need to be interpreted in terms of the impact on occupants. Occupants themselves are a rich yet underutilized source of direct information about how well a building is working, but the challenge is how to collect both the positive and negative feedback in a systematic way. This has been at the core of research underway at UC Berkeley.

 Center for the Built Environment

The Center for the Built Environment (CBE) is a collaborative research organization that links faculty, researcher, and students with a consortium of firms and organizations that share a commitment to improving the performance of commercial buildings. The Center has two broad purposes, represented in a wide range of research projects of relevance to the building industry. First, we develop ways to “take the pulse” of occupied buildings, looking at how people use space, what they like and don’t like, and we link those responses back to physical measurements of indoor environmental quality. Secondly, we study technologies that have the potential to make buildings more environmentally friendly, more healthy and productive to work in, and more economical to operate. These range from envelope and HVAC systems, to controls and information technology. Our industry partners represent architects, engineers, contractors, manufacturers, utilities, building owners, and government organizations. Our current CBE Industry Partners are Armstrong World Industries, Arup, CA Dept. of General Services, CA Energy Commission, Charles M. Salter Associates, CTG Energetics, Flack + Kurtz, Guttmann & Blaevoet, HOK, PG&E Pacific Energy Center, Price Industries, RTKL Associates, SOM, Southland Industries, Swinerton Buildings, Stantec, Steelcase, Syska Hennessy Group, Tate Access Floors, Taylor Engineering, Trane, US Dept. of Energy, US General Services Administration, Webcor Buildings, and York International.

Survey Page_acoustics The CBE Survey

CBE has developed a web-based indoor environmental quality survey to help designers, building owners and operators, and tenants evaluate how well their office buildings are working from the occupants’ perspective. Advantages of the web-based format are: 1) it is quick and inexpensive to use; 2) it facilitates more focused and detailed feedback (particularly, when the occupant indicates dissatisfaction with a certain area); and 3) survey results can be accessed using an automated, advanced reporting tool that allows users to filter, aggregate, compare, or benchmark their data. The core CBE survey measures occupant satisfaction and self-reported productivity related to nine environmental categories: office layout, office furnishings, thermal comfort, air quality, lighting, acoustics, cleanliness and maintenance, overall satisfaction with the building, and with the workspace. Additional, custom survey modules can be added, which would enable you to gather data about additional topics, depending on available building features or the client’s particular issues. Examples of existing modules include accessibility, safety and security, daylighting, and operable windows.

To date, the CBE Survey has been implemented in nearly 300 buildings, with over 41,000 individual responses, making it the largest database of its kind. The survey can be used as a diagnostic tool for individual buildings, to enable designers or building owners to evaluate specific aspects of their building design features and operating strategies, identify problem areas, and help prioritize investments for improvements. Users can do both before and after surveys to evaluate the effectiveness of changes in the design or operational improvements, or before and after a move. The database is also useful for evaluating trends across many buildings. By using a standardized instrument to collect data from a wide variety of office buildings, we are able to mine the data to look for trends or comparative analysis in the performance of particular design strategies or technologies. By utilizing the full database, clients can also evaluate how their building is doing in comparison to groups of buildings in the same or different categories.

The CBE Survey is being used in a wide variety of contexts, for both private and institutional clients. In some cases, we are contacted directly by architecture and engineering firms to study their buildings (recent examples include Arup, Chong Partners, EHDD, ELS, Enermodal Engineering, Glumac, HKT, HOK, Keen Engineering, Moseley Architects).

The U.S. General Services Administration (GSA) is using the CBE Survey to evaluate tenant satisfaction in up to 100 buildings each summer as part of their facility management assessment program, replacing their previous paper-based survey administered by Gallup. We are also developing and administering new surveys as part of GSA’s Workplace 20/20 initiative, which focuses on the interrelationships between people, space, technology, knowledge, work process, and organizational effectiveness.

With UC San Francisco, we have developed a new module to evaluate laboratories. We completed several baseline surveys of UCSF facilities, and we will continue to evaluate many of their new lab facilities.

As a one-year promotion, we offered the CBE Survey free for LEED-certified buildings, to improve our understanding of how green buildings were performing in the field. We have also been contacted independently by architects or building owners who can use the CBE Survey to achieve a LEED-NCv2.2 credit for thermal monitoring.

Internationally, we have collaborated with Indoorium, a Finland-based consulting firm specializing in indoor air quality, lighting, and acoustics, to evaluate 20 buildings and develop multi-lingual capabilities for the survey.

And here on the UC Berkeley campus, in Cris Benton’s Arch 249: Secret Life of Buildings, students surveyed 13 campus buildings and discovered that the deferred maintenance of recent years is keenly felt!

We are currently embarking on new projects to use the CBE Survey to evaluate some of the recent AIA-COTE Top Ten Green Projects, and to survey occupants of the new San Francisco Federal Buildings, both in their current spaces and then after they move later this year.

And finally, we utilize the CBE Survey extensively in our own research projects investigating technologies such as underfloor air distribution, operable windows, demand response technologies, and high performance facades — often combining the survey with detailed indoor physical measurements.

Survey Results_Avg ScoresLessons Learned

Looking at the entire database, of all the environmental attributes evaluated in the CBE Survey, acoustics consistently receives the lowest ratings, followed by thermal comfort and air quality. The most common sources of dissatisfaction with acoustics relate to sound privacy (people overhearing others’ private conversations) and distractions from hearing people’s conversations while talking on the phone or to others in neighboring areas. Much less frequent were complaints about excessively loud sounds, noise from the HVAC system or office equipment, or outdoor noises (even in buildings with operable windows). Not surprisingly, people with private offices are significantly more satisfied with acoustics that those in open plan spaces. However, when we looked at the influence of open plan design, we were surprised to find that the absence of partitions provided higher satisfaction scores than having partitions, yetpartition height itself had no discernible effect. This suggests that visual privacy may lead to unrealistic expectations of acoustic privacy. When people have a full view of their co-workers, they are either more courteous at keeping their voices lower, or change their expectations and are therefore not disturbed by the lack of privacy.

ASHRAE publishes standards for both thermal comfort and acceptable air quality in buildings (ASHRAE Standard 55-2004, and 62.1-2004, respectively), both recommending conditions in which 80% of the occupants are satisfied. But when we look at satisfaction scores from our database, we find that buildings are falling far short of these standards. It was disturbing to find that only 11% of the buildings met the intent of the thermal comfort standard, with an overall average of only 59% of the occupants expressing satisfaction with the thermal environment. Thermal dissatisfaction was most commonly related to people feeling that they did not have enough control over their environment, in addition to complaints about air movement being too low. This is particularly interesting given that thermal comfort standards are geared towards limiting air movement, mistakenly believing that drafts are a more common problem.

Responses to air quality were only slightly better, with only 26% of the buildings meeting the intent of the standard, and on average 69% of occupants are satisfied with the air quality. The most common complaints were that the air was stuffy or stale, or smelled badly, with the most frequently identified sources being food, carpet or furniture, or other people.

Not surprisingly, we found that satisfaction with both thermal comfort and air quality increases significantly in buildings that provide people with some means of personal control over their environment, such as thermostats or operable windows. The opposite was true for people with portable heaters and fans, indicating that the presence of these devices may have been a result of inadequate performance of the centralized HVAC system. Given the relative energy intensity of these portable devices, it is clear that providing for personal control should be a thoughtful and integrated part of the overall building design, rather than an afterthought.

We also did a comparative analysis of 21 green buildings, 15 of which were LEED-rated. In comparison to the rest of the database, occupants in these buildings expressed higher rates of satisfaction with thermal comfort and air quality, and with the building overall. Contributing reasons for this include improved ventilation, green materials with reduced off-gassing, solar gain control, operable windows, task-conditioning, and other means of personal control. In contrast, we didn’t see any significant improvement in lighting and acoustic quality in the green buildings. With regard to lighting, occupants consistently enjoyed and valued higher levels of daylight and access to views, but there were often problems with glare (particularly on computer screens), and inadequate electric task lighting or provision of controls over the lighting. High levels of dissatisfaction with acoustics in the green buildings were often attributed to problems with sound privacy and noise distractions, often exacerbated by the high ceilings and open plan layouts that are beneficial for daylighting and natural ventilation. Additional factors influencing the acoustics in these buildings were often harder surfaces associated with minimal use of textiles as a way of avoiding the off-gassing.


Providing workers with a quality indoor environment should be a goal of any building design, but is particularly important for green buildings that claim to be more responsive to supporting occupant comfort, health and productivity. Improving the quality of our buildings critically depends on accountability and learning from experience – what works, what doesn’t, and what choices about building design or operation can make the biggest difference. The voices of the occupants are an invaluable component of that assessment. As we move towards embracing high-performance, green buildings as the industry standard (as we must), we must also insist that post-occupancy evaluations be a natural part of that process. In the end, everyone benefits from learning how a building performs in practice.


I’d like to acknowledge the members of CBE who have contributed to this work, including Charlie Huizenga, Leah Zagreus, Sahar Abbaszadeh, David Lehrer, and CBE Director, Ed Arens. We also acknowledge the numerous students from Architecture and other departments on campus who have contributed to and received financial support from the Survey project.

For more information:

To see a demo of the CBE Survey and reporting tool, or to find out how to use the CBE Survey in your building, see:

Or send us an e-mail at:

For more detailed discussions of this subject see:

Abbaszadeh, S., L. Zagreus, D. Lehrer and C. Huizenga. Occupant Satisfaction with Indoor Environmental Quality in Green Buidlings. Indoor Air 2004; 14 (suppl 8) December 2004. 65-74.

Huizenga, C., S. Abbaszadeh, L. Zagreus and E. Arens. Air Quality and Thermal Comfort in Office Buildings: Results of a Large Indoor Environmental Quality Survey. Proceedings of Healthy Buildings 2006, Lisbon, Vol. III, 393-397.

Zagreus, L., C. Huzenga, E. Arens, and D. Lehrer. Listening to the Occupants: A Web-based Indoor Environmental Quality Survey.   Indoor Air 2004; 14 (suppl 8) December 2004. 65-74.

Gail Brager is Professor of Building Science in the Department of Architecture, and Associate Director of the Center for the Built Environment.


CAR-SHARING | Moving into the mainstream

For decades the American Dream was synonymous with car ownership. The number of vehicles surpassed the number of households in the United States in the 1920s, and currently, around 92% of households own at least one automobile. Even so, many people remain car-free or car-limited.

Thousands of young urban students and professionals chose homes to be close to work, school or transit, and commute, shop, and play mostly by transit, bicycling or walking. Additionally, there are thousands of households which, due to issues of affordability, have fewer vehicles than workers, or have no vehicles at all. On the other hand, there are also many households with extra vehicles which are hardly used. For all of these situations, “car-sharing” – the idea of having access to a car and paying for it only when you need it – provides a suitable option. For young professionals, it can improve mobility on those occasions when a car is needed, when in the past a car would have been rented or borrowed. Similarly, for low income households, it can add mobility at important times when other options are too time-consuming or inconvenient. For households with extra vehicles, selling the vehicle and car-sharing instead can eliminate the costs of ownership for the little-used vehicle.

For all of these reasons and more, car-sharing has taken off in many major U.S. cities. By now, residents in major metropolitan areas probably took notice of the strangely painted shared-car vehicles zipping around. As of 2005, there were 28 car-share systems in 36 cities in North America, with a total membership of over 75,000, and a total shared fleet of over 1100 vehicles. [1] Commercial car-sharing began in Europe in the 1980s and came to the U.S. around 1994. [1]

They all work along similar lines: the car-share operator owns and maintains a fleet of cars, the scheduling system, website, etc. The cars are placed in special, reserved parking spots in various locations in the city. Anyone can become a car-share member (with certain restrictions for those under 21). Members can use any car in the system, as long as it is available. They can check availability of any car by phone or internet and reserve the car at the location for the time frame they desire. Members have a universal key which opens and activates any car in the system. During their reservation period, they can use the car as much as they please. They can extend their reservation during use by phone or internet, as long as the car hasn’t been reserved immediately afterwards by another member. At the end of the month, the member is billed for their use, plus small monthly membership fees, if any. There are certain restrictions that help things run more smoothly; the hefty penalty for a late return helps ensure that users plan realistic reservation times and don’t leave the next user waiting.

Each system has a different system of rates. One local Bay Area operator charges 44 cents per mile and four dollars per hour during the day, or two dollars per hour at night. Another operator charges 8 dollars per hour with no charge for mileage. Some operators offer various types of vehicles and might charge different rates for each vehicle. A number of operators offer car-sharing and compete head-to-head in the different cities, placing competing vehicles right next to each other in a parking lot.

Because car-sharing has the potential to reduce automobile ownership for some, meanwhile increasing access to automobiles for others, the impact of car-sharing on urban travel and the environment is difficult to unravel. Professor Robert Cervero and a team of researchers and students have been working to understand these relationships for the past five years, supported by a Value Pricing Demonstration Grant from the U.S. Department of Transportation. Planning for the opening of City CarShare, a non-profit car-share operator in San Francisco, the team took a longitudinal approach. They tracked a group of car-share members and “non-members” over four years, beginning before the opening of the program, in order to reveal the impacts of car-sharing on travel consumption and vehicle ownership and make strong statements about the impacts of car-sharing.

Those who signed up to immediately join the program formed the “member” group, while those signing up to one day become active members functioned as the “non-member” control group. These non-members were ideal controls because they displayed comparable levels of motivation and interest, having taken the time to sign up for the program, but had not formally joined due to factors like there not being shared vehicles in their neighborhood. The first set of surveys was conducted several weeks before City CarShare’s March, 2001 inauguration. Similar surveys were then conducted of both groups three months, nine months, and two years into the program. The fifth and final set of surveys was conducted in May of 2005. As a result, the research team reached some main conclusions of the work and important implications for urban transportation policy, beginning with trends in car-share usage among members, followed by comparisons between members and non-members.

From the initial March 2001 opening in San Francisco in early to mid-2005, City CarShare grew tremendously. The number of points-of-departure (PODs) grew from 6 to 43, and the number of shared vehicles grew from 12 to 87. Part of this expansion resulted from the introduction of the program to Berkeley and Oakland in 2003. Active membership in City CarShare has trended upwards from over 1800 in September 2002 to 3800 in May 2005. The monthly average number of reservations grew from less than a thousand during the first year to well over 5000 by mid-2005. Members logged 106,000 miles in CarShare vehicles in the month of May, 2005.

The most common purpose for car-sharing was shopping, followed by social-recreational travel and personal business, with work trips constituting only around 10% of car-share trips. Around two-thirds of CarShare trips were made by the driver alone, with no passengers. The highest vehicle occupancies were for trips to school (nearly 2 persons), and the least discretionary trips were made mainly by solo-drivers. CarShare users were asked what modes they would have otherwise taken had car-sharing not been available. Interestingly, respondents claimed that 30% of trips would likely not have been made. For trips that would have been made, car-sharing draws more trips from public transit than any other modal option. To access shared cars, most walked (78%), took transit (14%), or biked (6%).

Looking at overall travel patterns, car-sharing made up 4.8% of members’ total daily trips, up from 2.2% three months into the program but down from 8.1% at the nine-month mark. Adjusting for trip length, car-sharing made up 5.4% of total vehicle miles travelled (VMT) by members. The overall most popular form of conveyance by members – representing 47.6% of all trips – was “non-motorized” (i.e., walking or cycling). Non-members were twice as likely to use a private car, and significantly less likely to take transit, compared to members. Members generally took “green modes” to work or school: nearly 90% of their journeys to work or school were by public transit, foot, or bicycle – a far higher share than for non-members. Members and non-members also differed in how they made shopping, social, and personal business trips, with members more likely to take transit or non-motorized modes. Most members and non-members have a transit pass, own a bicycle and many clearly have options for private car travel. Non-members were slightly more likely than members to have off-street parking (56% versus 41%).

City CarShare’s first wave of members were found to be fairly unrepresentative of the Bay Area’s and even San Francisco’s population, drawn disproportionately from professional-class residents who did not own cars and who lived either alone or in non-traditional households. This pattern generally held four years after City CarShare’s inception. In 2005, whites made up 82.8% of surveyed members (considerably above the 49.6% and 48.8% share for San Francisco and Alameda County, respectively). Members’ median annual personal income of $58,150 was above the census averages for San Francisco as well as the East Bay. Car-share membership also ran in the family: 32.6% of surveyed members’ reported another City CarShare member in the household.

In 2005, 62.8% of members were from zero-vehicle households and 28.7% were from one-vehicle households. Thus, 91.5% were from 0-1 vehicle households – above the 83.3% share during the program’s first year and well above the average of 70.6% for all San Francisco households. Members were half as likely as non-members to have acquired a vehicle, and about as likely to have reduced car ownership since 2001. Consequently, for every 100 member households, about 7 net vehicles were shed, while for every 100 non-member households, about 3 net vehicles were added during the period.

Compared to the first survey (“pre-car-share” — February 2001) and the fourth survey (“second anniversary” – March 2003), mean daily travel distances of City CarShare members fell slightly by the 2005 survey. For non-members, they rose over the long-term but largely stabilized over the 2003-2005 period. None of these changes, however, were statistically significant. Mean travel times steadily fell for both groups over the three survey periods, although more rapidly for non-members. Average travel speeds rose markedly among members, in part from the substitution of City CarShare trips for travel formerly by foot, bicycle and transit. In effect, car-sharing has enhanced mobility, allowing members to conveniently reach more destinations in and around San Francisco.

During City CarShare’s first two years, average daily travel (VMT) fell slightly for members yet increased for non-members. In order to understand differences in the mix of modes and occupancy of the vehicles by members and non-members, we adjusted the mileage to make a Mode-adjusted-VMT (MVMT). For example, a mile by transit or carpool was discounted compared to a mile as a solo driver because of the differences in environmental impacts. For members, MVMT fell by 67% over the long term (2001 to 2005) and by 38% over the intermediate term (2003 to 2005). Such declines were a combination of not only shifts to “green modes” and shorter travel, but also relatively high occupancy levels for private car trips, including those in City CarShare vehicles. MVMT for non-members rose in the first two years but like with members, appear to have fallen some since 2003.

Accounting for the differences in fuel economies among personal cars used by members and non-members, as well as the shared cars (which include mostly small cars and hybrids), members’ average daily fuel consumption fell steadily during the program’s first four years. This likely reflected a combination of members reducing private car ownership, switching to more fuel-efficient City CarShare vehicles, and carrying passengers for many car-share trips. By comparison, mean fuel consumption rose among non-members during the first two survey periods and fell during the 2003-2005 period.

Before and after comparisons from the first four years of the City CarShare program reveal declines in travel consumption among members compared to non-members. While most of these declines attributable to car-sharing accrued during the first several years in recent years levels of travel suppression appear to have stabilized or perhaps slightly reversed themselves. This makes sense – a typical member can only reduce travel so much. Though averages level off, as membership grows, the total impact of car-sharing continues to grow accordingly.

A statistical model of car ownership shows that membership in City CarShare and living near a POD significantly increases the likelihood that an individual lives in a car-free household. In a model of changes in car ownership, member status significantly predicts a reduction in car ownership during the period from 2001 to 2005. Similarly, having a transit pass and having at least one POD near one’s residence were both associated with net declines in household cars. Overall, members were half as likely as non-members to have acquired a vehicle during the 2001 to 2005 period and about equally as likely to have reduced car ownership since 2001. In essence, for every 100 member households, about 7 vehicles were shed, while for every 100 non-member households about 3 vehicles were added during the period. A statistical model of the choice of using car-sharing or otherwise for a trip revealed that members were less likely to choose car-sharing for work trips and that car-sharing decreased with increasing numbers of vehicles owned per household member. In this light, car-sharing is seen to be self-reinforcing: it facilitates the reduction in the number of private vehicles in the household, which in turn induces more car-share use.

Statistical models showed that City CarShare membership was associated with a reduction in daily VMT after controlling for respondents’ socio-economic characteristics. All else being equal, City CarShare membership predicted lowered daily travel by 7 vehicle miles (equal to about 1/3 gallon of gas per day per member). Additionally, the model showed that residing in San Francisco (compared to the East Bay) predicted a reduction in travel by 3 miles, owning a bicycle cut travel an additional 4 miles, while on the other hand, every additional car owned per household member raised daily VMT by 13 miles. The combination of being a City CarShare member, owning a bicycle, and reducing car ownership all serve to shrink a household’s ecological footprint in the San Francisco Bay Area. Increasing the net impact of car-sharing can only be achieved by adding more members.

Based on the five surveys of City CarShare members and non-members, there is clear evidence of sustained net reductions in car-share members’ VMT and fuel consumption some four years into the City CarShare program, due mainly to shorter, higher occupancy, and reduced private car travel during the first several years of the program. In relative terms, the biggest long-term environmental benefits of car-sharing in the San Francisco Bay Area came from reduced gasoline consumption, followed by VMT reductions, and reduced travel distances. Car-share members’ propensities to walk, bike, take public transit, and when they drive, to have other occupants in the vehicle, largely account for these sustained benefits. Reduced travel was matched by increased accessibility afforded to those who joined City CarShare. Rising personal benefits matched by declining social costs (declining VMT, fuel consumption, vehicle ownership) suggests car-sharing is a “win-win” proposition – benefiting users and non-users alike.

The circularity between car-share membership and car-shedding is not unlike that of car ownership and induced travel. Membership was associated with reduced car ownership, and reduced car ownership was associated with more car-share travel. It was not just average VMT that fell among members relative to non-members. Because car-share vehicles tend to be small, fuel-efficient, and carry several people, per capita levels of gasoline consumption and accordingly greenhouse gas emissions have also trended downwards. Mindful of the cumulative costs of driving, car-share members, we believe, have also become more judicious and selective when deciding whether to use a car, take public transit, walk, bike, or even forgo a trip.

These results point to important implications for larger urban planning issues. Car-sharing could become an important component to improving mobility for low-income families, without the heavy burden of vehicle ownership costs. It could also delay or reduce the acquisition of vehicles by young urban residents who may have growing mobility needs as incomes rise. There are also important synergies with urban development to consider. While infill and transit oriented developments are growing in importance in most metropolitan areas in the country, pressures remain on developers to supply parking at traditionally high rates, reducing the cost effectiveness and profitability of potential projects. Car-sharing has been shown to reduce vehicle ownership rates among members, and may become an important element to infill proposals with lower parking to unit ratios. Indeed, at least one large housing project in San Francisco house City CarShare vehicles in exchange for lower parking requirements. Furthermore, project proposals involving car-sharing may strengthen their case for approval because it can be shown that car-share users tend to travel more judiciously and reduce their negative traffic impacts.

For all of these reasons and more, car-sharing is growing beyond just a niche and becoming a common site across the country. And with further urban infill development, rising gas prices, and growing environmental concerns, the market potential is likely to grow. And with that growth comes lower parking pressures, traffic, fuel use and improved travel options for households with a wide range of travel needs.


This research was supported by a Value Pricing Demonstration Grant from the U.S. Department of Transportation. We thank the staff of City CarShare, Billy Charlton of the San Francisco Transportation Authority, Mike Mauch of Institute for Transportation Studies at UC Berkeley, and Mike Duncan and Chris Amado from UC Berkeley’s Institute of Urban and Regional Development for their help with this research.

Solar Power Shines

Alameda County is reducing CO2 emissions by 1,000+ tons per year. It is one of the nation’s earliest proving grounds for the U.S.’s fastest growing renewable energy technology.

No other county in the U.S. better exemplifies the thoughtful and ambitious deployment of solar power than Alameda County.

Alameda County has been at the forefront when it comes to using solar power — and demonstrates continued leadership in this arena. At the county level, Alameda is the nation’s largest deployer of solar power, with a total of 3.0 MW of solar photovoltaics (PV) commissioned at nine County-owned facilities.

Alameda County was keen to deploy smart energy strategies — integrating solar generation and energy efficiency measures into county-owned and operated facilities. For years, the County has been a leader in smart energy investments; this is a direct result of the vision and leadership of the County’s Board of Supervisors and General Services Agency to reduce the County’s annual overall energy usage and costs.

A number of cost-effective energy efficiency programs were launched in 1993, when the County’s General Services Agency hired its Energy Program Manager, Matt Muniz, P.E. One of Muniz’s first projects was to retrofit over 12,000 fluorescent light fixtures with energy efficient T-8 lamps and electronic ballasts and install innovative lighting controls throughout the County’s Santa Rita County Jail in Dublin, CA. Later Mr. Muniz’s energy team replaced over 550 inefficient fractional horsepower exhaust fan motors with premium efficiency motors at a payback of less than one year. Both of these projects are part of Pacific Gas & Electric’s (PG&E) “PowerSaving Partners” demand-side management program. As a PowerSaving Partner, the County has received over $3.2 million in direct incentive payments and ultimately reduced electricity costs at its Santa Rita Jail by one-third.

Charged with the task of achieving even greater energy savings at other Alameda County facilities, Mr. Muniz and his energy program colleagues implemented a number of other energy efficiency measures that presently total over $4 million in annual cost avoidance savings. These measures included lighting retrofits in 95% of County owned-buildings, the installation of state-of-the-art building automation systems in 25 facilities, replacement of most chillers with energy efficient and CFC-friendly equipment, and installation of Variable Frequency Drives to the HVAC systems in County facilities.

In early 2000, the City of Oakland was evaluating ‘green’ electricity purchase options and met with executives of PowerLight Corporation, a subsidiary of SunPower Corporation. PowerLight’s protective insulating solar electric rooftop technology gave them a new demand reduction challenge: How could he and his colleagues continue to reduce energy costs at the Santa Rita Jail by generating electricity from an onsite solar power plant?

“I thought that we had completed all the cost-effective energy saving measures that were possible at the jail,” said Matt Muniz, P.E., Alameda County’s Energy Program Manager. “But with over a half-million square feet of unused flat roof space at the jail and the recent drop in prices for solar cells I immediately concluded that solar electricity was the perfect solution for further demand reduction.”

How could Alameda County achieve its vision of becoming a leader in solar energy? Could the economics of large-scale solar PV pencil out? How would such a large capital purchase be financed?

The answers to these questions began with the abundant solar electric incentive programs available in California — the predecessors to today’s statewide California Solar Initiative program — that made the solar electric system affordable in its own right. However, an even more affordable idea was devised: to combine on-site solar electric generation with reductions in the jail’s overall energy use by implementing energy efficiency and sophisticated energy management measures.

Soon thereafter PowerLight Corporation contracted with its strategic partner, CMS Viron Energy Services (which was acquired in 2003 by Chevron Energy Solutions), to showcase the synergy between the latest advancements in solar PV and state-of-the-art energy efficiency technology.

Alameda County, PowerLight, and Viron then crafted an integrated solar electric generation and energy efficiency plan with the goal of exceeding the County’s 10% internal rate of return threshold for energy projects. It would soon serve as a model for other local governments and large commercial customers concerned about rising electricity rates, reliability, and the nation’s increasing reliance upon polluting sources to supply electricity.

The Santa Rita Jail offers proof that solar and energy efficiency are a synergistic blend of technological innovations well suited to respond to today’s stressed power grid in California. By linking the largest rooftop solar PV system in the U.S. explicitly with energy efficiency upgrades and state-of-the-art energy management software, Alameda County is able to reduce its peak power consumption, without any expenditure from its general fund. Some of the innovations that make the Santa Rita Jail project noteworthy include:

Solar Power Installation Provides Multiple Benefits:
PowerGuard® tiles incorporate state-of-the-art solar cells backed with insulating polystyrene foam, turning the sun’s free energy into usable power while increasing building thermal insulation and extending roof life. A key innovation of these roof tiles is that they can be installed on flat rooftops without penetrating the roof membrane.

Applying a “Cool Roof” Membrane with High Solar Reflectivity:
By applying a “Cool Roof” reflective coating on the jail’s existing roof, the roof area not covered by solar tiles now reflects 65% of the solar energy. This effectively reduces the roof’s temperature during the hot summer months by 50 degrees Fahrenheit. Peak electrical demand reductions result from the reduced air conditioning requirement in the occupied spaces below.

Replacing Inefficient Equipment Generates Large Electricity Savings:
Large electricity savings are garnered by replacing an old inefficient chiller with a new 850-ton high efficiency chiller that does not use CFCs that contribute to the degradation of the ozone layer. New variable speed drives attached to the new chiller, chilled water pumps, and cooling towers will respond directly to the precise real-time cooling requirements needed to deliver chilled water instead of operating at 100% speed all of the time.

Smart Energy Management Optimizes Overall System:
Implementation of Utility Vision™, a computerized energy management system developed by CMS Viron automatically reduces peak power consumption during dips in solar power generation. These dips may be caused by normal weather conditions such as cloud cover. For example, if clouds block the sun for five minutes on a summer afternoon, Utility Vision automatically reduces power consumption proportionately so that no additional purchases of expensive peak priced electricity are necessary.

Following the installation of the solar system at the Santa Rita Jail Alameda County was so pleased that it decided to add an additional 1.8 MW of clean solar power into its energy mix. Several more solar arrays were installed at the following County venues between 2003 and 2007 — the Office of Emergency Services, the Environmental Health Services, the Winton Avenue Government Building, the Wiley W. Manuel Courthouse, Hayward Public Works, Fremont Hall of Justice, and the new Juvenile Justice Center.

Alameda County’s deployment of solar power has played an enormous role in bringing down utility costs. By integrating solar power generation with energy efficiency measures, Alameda County has demonstrated enormous leadership in defining both clean and cost-efficient energy solutions. The County’s cumulative 3.0 MW of solar power systems generate 4 million kilowatt-hours of electricity annually, much of it produced during peak demand times, when the utility grid is the most strained and electricity is most expensive.

Overall, Alameda County’s solar energy investments are enabling the County to meet eight percent of its electrical needs at its facilities with clean, renewable solar power. Its grid-connected solar systems help reduce the County’s electrical demand; consequently, it saves over $500,000 annually in avoided electricity purchases. These savings add to the $3.5 million annual savings associated with its energy efficiency measures.

The environmental benefits of Alameda County’s deployment of solar power and other energy efficiency improvements are considerable. Over the next 30 years, the environment will be spared from thousands of tons of air emissions such as nitrogen oxides, sulfur dioxide and carbon dioxide. These emissions are to blame for our urban smog, a primary cause of asthma and other respiratory diseases and contribute to global warming. And over that same 30 years, the solar-generated electricity will reduce carbon dioxide emissions by 45,000 tons. These environmental savings are the equivalent to planting over 270 acres of trees or avoiding driving 71 million miles on California’s roadways.

Energy performance data is posted on the internet so that Alameda County, governmental agencies, solar customers and other interested parties can review and analyze the performance of Alameda County’s solar installations and the energy efficiency measures.

Alameda County has shown that large-scale solar systems can indeed be cost effective investments and even more cost effective if the system is integrated with the facility’s energy management infrastructure.

The solutions offered by effective deployment of solar power reflect the future of the energy industry and point the way toward stable power costs and pollution-free, local energy choices. As volatility in energy pricing continues, increasingly the public and private sector will follow Alameda County’s visionary lead.

The Impact of Energy Consumption on the Environment

What is the Biggest Culprit? Concerns about the impact of energy consumption on the environment, especially global climate change, have finally penetrated public consciousness to the point where significant political action is beginning to happen.

USEnergy3 copyAny number of events can be cited as triggering this step change in consciousness. Al Gore’s movie An Inconvenient Truth, numerous cover articles by our leading weekly magazines, a continuous stream of newspaper articles, scientific reports from prestigious committees, appeals to the President by business leaders, politicians, and scientists, etc., have outlined the risks and challenges to the planet in compelling detail. As Governor Arnold Schwarzenegger commented when he introduced Executive Order S305 on greenhouse gas reduction, “I say the debate is over. We know the science. We see the threat. And we know the time for action is now.”

The question is: where should we focus our efforts? We can begin by asking: where are the biggest culprits and what are the most immediate cost effective strategies, but the challenge is more fundamental than the idea of mitigation or conservation, as important as they are. Ultimately, we must rethink and convert our 200-year-old fossil fuel economy to renewable sources. An even more fundamental question is: can we do it in time to avoid catastrophic change and human hardship?

The recent announcement at UC Berkeley of a $500 million grant by oil giant British Petroleum (BP) to develop biofuels is not only by far the largest alliance between industry and the academies, but also the kind of investment and vision necessary to bring renewable energy swiftly to market. BP’s grant will fund hundreds of researchers in 25 teams, 18 at UC Berkeley and Lawrence Berkeley National Laboratory (LBNL) and 7 at University of Illinois Urbana-Champaign, while BP will assign up to 50 of its own researchers to join the teams. The potential of this landmark interdisciplinary effort is planetary. LBNL Director Steve Chu has estimated that if the acreage which American farmers are currently subsidized not to cultivate were planted in “switch grass” and if ethanol from this cellulose source could be brought to market at the efficiencies demonstrated in the lab, it could provide as much as 100% of the country’s transportation fuel needs. UC Berkeley Chancellor Robert Birgeneau has characterized the effort as “our generation’s moon shot.” Charles Zukoski, Vice Chancellor of Research at the University of Illinois Urbana-Champaign, described it as launching “a new age for agriculture, altering the energy economy of the planet.” As essential and groundbreaking as this effort is, how big an impact will it have on the problem?

World Energy Supply Bar GraphAn examination of our energy consumption by broad sectors reveals the following approximate breakdown: 27% transportation, 30% industrial, 22% commercial, 21% residential. Almost all the energy consumed (90%) comes from fossil fuels, with the remainder from nuclear and renewables, including wind and hydro. When each sector is examined in greater detail, some surprising facts are revealed. Within the transportation sector, only 16% is consumed by cars and trucks, the remaining 7% goes to trains and planes. Thus, if all the transportation fuel for cars and trucks (as big a number at that is) were converted to biofuels, it would still only address 16% of the problem. So what is the biggest culprit?

As Ed Mazria has pointed out in his “2030 Challenge” to design and construction professionals, if you add up the residential and commercial sectors with the portion of the industrial sector consumed by buildings, it totals 48% of the total energy consumption! If you look at electric consumption by itself, 75% goes to operate buildings. With the projected increase in electrical demand planned to be met by coal-fired power plants, the impact of buildings is even more important. Quite simply, buildings are both the biggest problem and opportunity.

Mazria also points out that over the next 30+ years, we will build approximately half again as much new square footage as already exists and we will renovate about 50% of the existing square footage. This means that in the year 2035, three quarters of the built environment in the U.S. will be either new or renovated. This gives design and construction professionals the largest responsibility for making a real difference, but as Schwarzenegger has said “the time for action is now.”

We know from over 30 years of research and development since the last oil crisis in the early 1970s, that we can reduce the energy consumption in buildings by 50-70% through intelligent conservation and the application of passive solar heating, natural ventilation and careful daylighting. The question becomes how do we get the rest of the way to zero carbon buildings — i.e., buildings which generate all of their energy needs from renewables. This is the “moon shot” challenge to design and construction professionals.

With the loads for heating, cooling and lighting reduced dramatically by the strategies above, the remaining challenge is the electric loads for building equipment, appliances and especially the so-called “plug loads” for computers, televisions, kitchen and office equipment. Conservation in lighting and appliances, especially refrigerators, are the reason why electric consumption in California has been flat for the last 20 years in spite of population growth. This phenomenon has been called the “Art Rosenfeld Effect” because he pioneered the “energy star” rating system for all appliances, especially refrigerators. Natural competition in the market place, as a result, reduced energy consumption by 50%. His colleagues at LBNL pioneered in the development of high efficiency light bulbs with a similar

To achieve the goal of zero carbon buildings, the country will need the next generation in conservation technologies in all areas of electric usage, including lighting, appliances, televisions, computers, etc. Fortunately, many of these technologies are in the development phases and are on the way. As demonstrated in California by the “Rosenfeld Effect”, conservation will remain the single most cost effective first step. Nonetheless, buildings will still require electric power; even with reduced loads, and the challenge is can it be met by renewables?

Through our research at the college on the application of photovoltaics and wind technologies to buildings, we have discovered recent commercially available breakthroughs which are extremely promising. By integrating photovoltaics (PV) directly into building assemblies, like roofs and curtain walls, i.e., substituting existing materials with PV materials, the cost effectiveness of PV is already competitive in some markets, especially when compared with peak power. When the next generation of efficiency achieved in the lab (20%-40%) is brought to market in 3-5 years, the integration of PV into building assemblies should become a matter of course for designers.

The story about the integration of small-scale wind machines into building design is equally promising. A new generation of vertical axis machines, double-helix spiral-like rotors, seems to have solved many of the prior problems. Quiet, non-vibrating, effective at low speeds and multi-directional, their applications on roofs and facades offers multiple design opportunities.

When both of these technologies are combined, we have discovered that they have the potential of providing more than 100% of the total electric loads, on an annual average basis, after careful conservation. Yet, the final challenge is overcoming the intermittent timing of these renewables. What do you do if there is no sun and no wind, and you are unable to capture excess energy (when available) by running the meter backwards, i.e., using the grid as storage?

The final step to zero carbon buildings, for instance providing the backup to wind and solar, comes from a surprising source — the waste streams. In our research work on sustainable neighborhoods in China, we have discovered that food wastes, the sludge from primary sewage treatment and green wastes from the landscape, urban gardening and agriculture together generate a significant energy resource in the form of biomass. New technological breakthroughs in biogas generation use a two-stage anaerobic process to convert as much as 80% of the potential energy in the biomass into biogas — methane and hydrogen. This energy source can be put to many uses, for example: providing gas for cooking, compressed gas for gas-powered vehicles, or powering gas-electric turbines for the base or back-up electric loads.

solarFor this technology to be cost effective, however, it needs a minimum flow of biomass material equal to about 8-10 tons per day, or the waste created by a mixed-use, high density neighborhood of approximately 5,000 units of housing (15,000 people). While the construction of such a neighborhood is the exception in the U.S., 10-15 of these kinds of neighborhoods are completed every day in China. We have discovered that the three renewable energy sources, wind, solar and biomass together can provide all the energy for such a neighborhood. Indeed, the neighborhood can be a significant energy exporter to the grid — especially at peak demand during summer afternoons. The challenge of realizing such an integrated and self-sustaining system of energy supply is that it requires a whole new way of doing business for the design and construction industry. The developer, architect, landscape architect, civil engineer, mechanical engineer, city departments of planning and public works, have to operate under a whole new paradigm of collaboration and integration. But the rewards are planetary; zero carbon neighborhoods could become a reality.

In the end, the goal of achieving a carbon neutral future in the building sector is at least several years off, at the building scale. It will take multiple technology breakthroughs in all areas of energy conservation and renewables before the building will be an appropriate scale for supplying all of its own energy needs. On the other hand, a carbon neutral future is already achievable at the neighborhood scale. The question is: will planning, design and construction professionals seize the opportunity?

At CED we are striving to provide the educational foundation for our students which will prepare them to seize a leadership role in this effort. UC Berkeley tops a short list of institutions with the unique combination of breadth and depth needed to develop innovative design solutions and approaches to public policy. It requires not only the collaboration of multiple faculty in our three disciplines, but also reaching across campus to civil engineering, the energy and resources group and anthropology, listed below. CED is the only school in the country where this new paradigm has a chance of being realized and is exemplified by:

  • Elizabeth Deakin and Robert Cervario’s work in transit-oriented development and the making of walkable and bikeable cities with Michael Southworth
  • Tim Duane and Randy Hester’s work to reconcile competing demands on the ecosystem on the island of Hawaii
  • Judith Stilgenbauer’s work on green infrastrutures — the multi-functional and productive features of landscape
  • Galen Cranz’s examination of the social and cultural bases of a sustainable lifestyle
  • Our building science faculty – Cris Benton, Gail Brager, Ed Arens, and Susan Ubbelohde — work on energy conservation, daylighting, lighting controls, interfloor mechanized systems, dual mode buildings and user response to environmental quality
  • Our collaboration with The Berkeley Institute of the Environment (BIE) and Energy Resources Group (ERG) faculty – Inez Fung, Dan Kammen, — on renewable energy systems, solar, wind, and biomass
  • Anthropology Ph.D. student Shannon May’s work on the post occupancy evaluation of China’s fact eco-village

The greatest challenge is developing the institutional structure and pedagogy to create an effective framework for this interdisciplinary collaboration to flourish. The impact that the built environment has on our planet’s future has never been more critical to our survival and presents us with our greatest opportunity for change.

The Re-Envisionists

Questioning Urbanization in the Delta

Images of flooding New Orleans – literally the destruction of a major American city and loss of much of its population – have increased awareness of flood risk in the US. In California, the Sacramento-San Joaquin Delta has been much in the news recently, as the fragility of its levees (long understood by experts, but only recently appreciated by the public) has attracted the governor’s attention, leading him to propose massive re-investment. But even with higher, heavier levees, will the Delta be safe from flooding? Given the unique characteristics of the Delta, does it make sense in the long run for us to build houses below sea level there? Or could alternative scenarios that preserve open-space and infrastructure values provide more benefit and less risk to the San Francisco-Sacramento-Stockton metropolitan region of the future?

In hopes that this fresh experience created a ‘teachable moment,’ the Department of Landscape Architecture and the College of Environmental Design held a two-day symposium, ReEnvisioning the Delta, to consider the implications of the Delta’s ongoing urbanization and to explore alternative futures for the region. The symposium featured presentations on the physical characteristics and unique functions of the Delta, emphasizing its key role for infrastructure, agriculture, and open space within the San Francisco-Sacramento-Stockton metropolis, and on the dynamics of urbanization in the Delta and the surrounding region.

Urbanizing lands below sea level in the Delta strikes many as manifestly unwise and dangerous. Nonetheless, it is occurring now, at a rapid rate. Hans Johnson presented population data showing that the Delta is the fastest growing region in California, with population increasing at rates even faster than developing nations. Panel presentations by Carol Whiteside (former mayor of Modesto), Marci Coglianese (former mayor of Rio Vista and member of the Delta Protection Commission), and John Cain (Natural Heritage Institute) explained how escalating housing prices and a pro-growth political environment in local government are creating the enormous pressure to urbanize flood-prone lands. The author of the Delta Protection Act, former State Senator Patrick Johnson, showed how even the Delta Protection Commission established by the Act is not immune from these incentives to sprawling growth.

Bob Twiss presented an overflight of the Delta landscape that showed how these developments are consuming critical lands at the edge of the Delta that may be essential for future ecosystem management. Graduate student research completed for this symposium also projected future urbanization from general plans, proposed development footprints, aerial imagery, and other relevant GIS data layers. This is the first spatially explicit analysis of urbanization below sea level in the Delta and the likely consequences of that urbanization in the event of catastrophic flooding.

And that disaster potential is escalating. UCB Engineering Professor Ray Seed, who has just completed an NSF-funded study of levee failures in New Orleans, argued that the levees in the Delta are extraordinarily vulnerable to an earthquake-induced mass failure (although techniques exist to make them safe through extended public investment). The current 100-year flood protection standard to which the levees are built, meanwhile, leaves a very significant “residual risk” of a larger-than-100-year flood that could be immensely destructive. Tom Philp of the Sacramento Bee moderated panelists Mike Webb (California Building Industry Association), Ron Baldwin, (Director San Joaquin County Emergency Operations), and Tom Zuckerman (University Pacific, former counsel Central Delta Water District) in a discussion of the varying opinions on how to moderate disaster risks and who should be responsible for levee safety and potential liability.

The second day examined potential futures for the Delta, focusing on the Delta not as a set of problems, but as a place with its own unique history and character. As Jane Wolff, author of the Delta Primer, pointed out, it is a place that can be seen in several different ways — as at once an open space, an agricultural region, a wetland habitat, a recreational region, and an economic resource.

Subsequent talks shared the experience of land conservation efforts for each of these types of landscapes. Louise Mozingo argued that the creation of Central Park in New York and the Emerald Necklace in Boston show that recreational open spaces can be formed in advance of urbanization. Phyllis Faber showed that the history of agricultural land conservation in Marin County contains valuable lessons for the situation Delta farmers are facing. Bob Twiss talked about the land-use controls undertaken at Lake Tahoe to protect water quality, another pressing issue for the Delta today. Santa Monica Mountains Conservancy director Joe Edmiston advocated the use of a state-sponsored Conservancy model to protect conservation values in the Delta. Joe Bodovitz recounted the balancing of conservation and development in San Francisco Bay planning, and Pete Rhoads talked about the enormous planning effort underway to restore the Everglades. The Delta bears important similarities to each of these cases. Other panels, including such notables as John King of the San Francisco Chronicle, Margit Aramburu, formerly of the Delta Protection Commission, and Tom Waters of the US Army Corps of Engineers, expounded on some of these similarities and offered suggestions for moving forward in the Delta.

Innovative ideas for preservation of the Delta’s critical infrastructure, agriculture, and open-space access were also presented by Jennifer Brooke on behalf of the graduate students involved in the annual Tommy Church Design Competition. Interdisciplinary student teams developed plans and designs for a Delta park, recognizing its central role in the San Francisco-Sacramento-Stockton metropolis of the future. The jury awarded two first prizes to the teams of “Wet Feet Wanted,” (Elke Grommes, Mei Minohara, and Zachary Rutz), and “Delta Byways,” (Brooke Ray Smith and Stephen Miller).

Between historical precedents and visionary designs for the Delta’s future, there was no shortage of thought-provoking ideas for this critical region of California. What is needed, participants agreed, is better planning data and, more importantly, a widely shared vision for what the Delta should look like in the future. With the urbanization problem now on the political radar screen, planning efforts can now turn to the challenge of creating that vision of a more secure and resilient Delta region.

Water, Oil, and Wine Regional Planning and Design for a Post-Fossil Fuel Napa Valley

During the Fall Semester of 2005, graduate students in landscape architecture and environmental planning focused their efforts on long-range planning for the entire Napa River watershed. However, their charge was somewhat beyond the ordinary.

compost_areaplan_1 The Napa River Watershed drains into San Pablo Bay, and is home to the world famous wine region of Napa Valley as well as several small to moderate sized cities. With its headwaters at Mount St. Helena, the Napa River flows from wild slopes of the Mayacmas Mountains through picturesque vineyards toward and through the City of Napa and out past Mare Island and the city of Vallejo to San Pablo Bay. One of the most memorable and well-known geographic features in California, the Napa Valley is a highly compact watershed ranging from near wilderness to rural lands, to suburbs, to cities, to industrial zones in a mere fifty miles.

Beneath the surface of this apparent paradise is a web of relationships highly dependent on fossil fuels. From the natural gas providing electricity to homes, wineries and businesses to the oil providing gasoline for vehicles, and the petrochemicals for agriculture, the valley is held captive by the fossil fuel era. Like all regions of North America, the Napa Valley will of necessity undergo a very serious transformation to a post-fossil fuel reality. A compact, thriving watershed region like the Napa Valley allowed the class a laboratory to explore the patterns of land use and landscape that may emerge in the wake of declining fossil fuel supplies and the realities of global warming. The class presumption was simple: In thirty years, everything will change. Their job was to anticipate that change and guide it in constructive, fulfilling directions for all life forms and resources.

thincLed by Assistant Professor Jennifer Brooke and Beatrix Farrand Visiting Professor Robert Thayer, Professors Joe McBride and Matt Kondolf, and with the cooperation of the Napa County Environmental Planning staff members, students broke into six teams to investigate a number of critical dimensions of the river valley: Water; Land and Vegetation; Energy and Transit; Housing, Urban and Industry; Parks, Open Space and Tourism; and Agriculture, Food and Wine. These analysis teams conducted exhaustive reconnaissance on the state of the Napa River watershed with a view of likely conditions, potentials, and limitations thirty years out, when transit fuels would be more scarce and expensive, weather more extreme, population pressure more acute, and natural habitat and open space more precious.

Analysis processes were immediately followed by a master planning phase wherein student teams focused their efforts on components necessary to direct the future of the region. One team hypothesized the creation of a quasi-public initiative entitled “Common Roots”, a new twist on the contemporary CSA (Community Supported Agriculture) movement, proposing a multifaceted urban agricultural growing and distributing system with neighborhood markets and a centralized farmers market. With the goal of returning potentially productive but underutilized lands to the provision of local food, their presentation included a toolkit of strategies for small-scale, decentralized food production. Their work also included the addition of an Urban Agriculture element to the City of Napa zoning code, which would enable urban food production to be facilitated by local government yet run by a local non-profit board of directors.

Another team branded itself as “THINC Transit”, an acronym standing for “Transit Hybrid for an Integrated Napa Community”, and proposed a sophisticated yet highly feasible public transit system utilizing existing Wine Train rail rights-of-way and linking other potential transit corridors with existing BART and Amtrak lines to provide ferry, train, light rail, bus, and shuttle transit for the entire valley. Their final presentation included a highly detailed phasing plan for implementing the transit system, complete with a hypothetical and multi-modal schedule of arrivals and departures, including a by-reservation shuttle for the remote valley towns of St. Helena and Calistoga.

ag_potentialIn the final design phase, individual students chose site-specific design projects that would build upon various goals and findings from the analysis and master planning efforts completed earlier. These included a complex transit center expansion on the site of the BayLink Ferry in Vallejo; an adaptive reuse plan to turn a routine industrial park into a showcase venue for local organic food production, distribution and waste management; a combined constructed wastewater wetland/regional park and trail complex for Mare Island; a mixed use affordable housing community built on the abandoned glider port in Calistoga; upgraded recreational and habitat improvements to the estuarine wetlands near the Napa airport; and dense transit-oriented development of land along the proposed light rail line through the City of Napa.

Running successfully through the entire course was the theme of “Not Business as Usual.” In envisioning the rather substantive changes anticipated with respect to climate, rising sea levels, the peaking of oil, increases in population quantity and social diversity, potential widening of income gaps, and the future need to shorten the supply chain distance between sources and end uses of energy, food, water, and materials, class members prepared themselves for a future where the skills of landscape architects and environmental planners, as some of the most logical systems thinkers, will be most sorely needed.

Studio instructors were Jennifer Brooke, Assistant Professor of Landscape Architecture and Environmental Planning; Robert Thayer, Beatrix Farrand Visiting Professor; Joe McBride, Professor of Landscape Architecture and Forestry; and Mathias Kondolf, Associate Professor of Environmental Planning and Geography. Participating students were Patricia Algara, Jongkeun Choi, Noelle Cole, Astrid Diehl, Calder Gillin, Alethea Marie Harper, Joshua Kent, Freyja Knapp, Rusty Lamer, Erika Leachman, Miza Moreau, Jennifer Natali, Shiva Niazi, Songha Park, Natalie Pollard, Zachary Rutz, Brooke Ray Smith, Andreas Stavropoulos, Sutter Wehmeier, Alex Westhoff, Nicole Winn, Suzuko Yamada, and Liyan Yang.

Reclaiming The Walkable City

For decades urban designers advocated more walkable cities without much success. Finally, in the past few years the quality of the walking environment has become an important issue in planning and design in the U.S.

Siena Previously, transportation planners viewed movement by foot and bicycle as recreational, rather than legitimate transport to be seriously considered. A major shift in policy away from auto-centric planning, to mandated accommodation of the pedestrian and bicycle in federally supported transportation projects has stimulated numerous pedestrian and bicycle policies, plans, and built projects across the country. Recent studies on the many health benefits of walking have helped strengthen the case for making walkable cities.

Urban Design, Transportation Planning, and the Pedestrian

Urban design and transportation planning have evolved along distinctly different tracks over the past century, urban design focusing on the concrete experiential qualities of the built environment, generally at small to medium scale, and transportation planning focusing on more abstract function and efficiency for the motorist, at the scale of cities and regions. Before the “scientific” revolution in transportation planning, civil engineers in the U.S. were trained to deal with the character of the locale. The road was engineered to serve transportation needs, but also to fit in with the landscape and to enhance the experience of the user.

Beginning in the 1930s the profession of street and road design split in two separate directions: those who specialized in the technical aspects of transportation planning and engineering, and those who dealt with place-based design. While transportation planners have focused on abstract “macro” variables like capacity, demand, rate of flow, trip origin/destination analysis, congestion patterns, and regional land use patterns, urban designers and landscape architects have looked at “micro” variables, the form and use of local places. The consequences of this split for pedestrians and the built environment have been enormous.

Walkable Cities of the Past

Walkability was essential in cities before the automobile era. Streets of the preindustrial city were by necessity walkable, since everyone depended upon ready access by foot or slow moving cart, wagon, or carriage for access to jobs and the marketplace. Activity patterns had to be fine grained, density of dwellings had to be relatively high, and everything had to be connected by a continuous pedestrian path network. Cities of the middle ages were remarkable in their walkability and typically packed all the necessities of urban living into an area no more than ½ mile from the central square. For example, the entire built-up area of Urbino, Italy occupied only 300 acres yet housed 30,000 people. Early American cities like Boston were highly walkable, as well. Before major land filling operations began in the early nineteenth century, everything was on a small peninsula of little more than 800 acres where every point could be reached in a walk of less than one mile or ½ hour. Despite enormous growth and modernization, the central area still maintains its walkability, a rare situation for the American city.

High speed transport and the quest for efficiency killed the walkable city. Each advance in transportation technology — from horse drawn cart or carriage, to horsedrawn streetcar, to electric streetcar, to automobile and superhighway — has degraded the pedestrian environment. Hazardous high speed traffic broke up the fine grained pedestrian network and imposed barriers to free movement on foot. In ignoring the pedestrian experience, the street lost its intimate scale and transparency, and became a mere service road, devoid of public life. Modernist planning and design separated pedestrians from the automobile, shunting them off to raised plazas, skywalks, barren “greenways,” and sterile pedestrian malls. The automobile oriented values of Modernism have been codified in the transportation and street design standards that we struggle with today.

In the late postindustrial city it is impossible for the pedestrian or bicyclist to navigate freely. The street patterns of most residential areas built after 1950 are based on the discontinuous cul-de-sac rather than the interconnected grid. Block sizes are too large to permit a range of route choices and land use patterns are coarse with activities widely spaced and segregated by type. Streets are often over scaled and inhospitable to pedestrians and frequently lack sidewalks in order to reduce infrastructure construction and maintenance costs. The entire system has been designed for the convenience of the motorist (Southworth and Ben-Joseph 2003).

Why Walk?

WALKABLE SUBURB1The benefits of increasing walking are now recognized. Walkability is the foundation for the sustainable city; without it, meaningful resource conservation will not be possible. Like bicycling, walking is a “green” mode of transport that not only reduces congestion, but also has low environmental impact, conserving energy without air and noise pollution. It can be more than a purely utilitarian mode of travel for trips to work, school, or shopping, and can have both social and recreational value. It is also a socially equitable mode of transport that is available to a majority of the population, across classes, including children and seniors.

Compared with Europeans, Americans walk very little. Only 9 percent of total trips in the U.S. were by foot in 1990 but 84 percent were by car, whereas in Sweden 39 percent were by foot and 36 percent were by car. In The Netherlands and Germany walking and bicycle trips increase with age and account for over half the trips for people age 75 and older (Pucher and Dijkstra, 2003). In addition, only 6 percent of trips were by foot for Americans age 75 and older in 2000. (Frank et al 2003).

Walking can promote mental and physical health including cardio-vascular fitness, reduced stress, stronger bones, weight control, and mental alertness and creativity. Walking is the most accessible and affordable way to get exercise. As obesity has now become a major public health problem in the U.S., several studies have made connections between health and the design and planning of cities. They make a strong case for better design and planning of the pedestrian environment.

  • Three quarters of U.S. adults do not get enough physical activity, and one quarter is inactive in their free time. Nearly two thirds (64.5 percent) of U.S. adults are overweight and almost one third are obese according to a recent National Health and Nutrition Examination Survey (Ewing et al 2003). In contrast, European countries with the highest rates of walking and bicycling have less obesity, diabetes, and hypertension than the U.S. (Pucher and Dykstra 2003).
  • As little as ½ hour moderate activity such as walking or bicycling may be adequate for long term health, but only one quarter of the population achieves this (Frank et al 2003; Powell et al 2003).
  • People who live in “sprawl” are likely to walk less, weigh more, and have greater incidence of hypertension than people living in more compact areas (Ewing et al 2003). Residents of more walkable San Diego neighborhoods engaged in 70 more minutes of physical activity in the previous week and had less obesity; 60 percent of residents in less walkable neighborhoods were overweight (Saelens et al 2003).
  • Women between the ages of 70 and 81 who did more walking and other physical activity tended to have better cognitive function and less cognitive decline than those with less activity. Those with the highest levels of physical activity had 20 per cent lower risk of cognitive impairment (Weuve et al 2004). Men over 71 who walked the least (less than ¼ mile per day) had nearly twice (1.8 times) the risk of developing dementia as those who walked the most (Abbott et al 2004).
  • People who live in walkable neighborhoods may have higher levels of “social capital,” and are more likely to know their neighbors, participate politically, trust others, and be socially engaged (Leyden 2003).

Criteria for the Walkable City

“Walkability” might be defined as the extent to which the built environment supports and encourages walking by providing for pedestrian comfort and safety, connecting people with varied destinations within a reasonable amount of time and effort, and offering visual interest in journeys throughout the network.

What are the qualities of a walkable city? To encourage walking designers and planners need to go beyond utilitarian access and address several qualities of the path network.

1. The path network should be well connected without major gaps or barriers, both locally and in the larger urban setting. Connectivity of the path network is determined by the presence of sidewalks and other pedestrian paths and by the degree of path continuity and absence of significant barriers. While it is tempting for simplicity to measure walking distance to destinations radially “as the crow flies,” this approach can be misleading, especially when street patterns are coarse and fragmented. However, as patterns become finer grained and more interconnected, blocks become smaller with higher connectivity of paths, and the ratio of access for the “crow fly” measure to actual walking distance approaches 1:1.

In addition to path distances to various points, it is important to examine the amount of path choice. Density of path intersections and block sizes can be revealing: a high density of intersections and small block sizes usually correlates with a high degree of connectivity. Barriers to pedestrian access such as cul-de-sacs and dead end streets, or busy arterials, railroad or power line rights-of-way, rivers, or topographic features must be minimized.

Connectivity is best addressed when an area is being designed, of course, and is much more difficult to remedy once a place is built. Most of the post-industrial suburban landscape suffers from lack of pedestrian connectivity, typically with a pattern of disconnected cul-de-sacs and barrier arterials and highways. In some cases, connectivity retrofits might be possible, with pedestrian overpasses or underpasses across barriers, or traffic calming devices. Cul-de-sacs might be connected to provide a continuous bicycle and pedestrian system (Southworth and Ben-Joseph 2004).

2. Pedestrian paths should be linked seamlessly, without interruptions and hazards, with other modes such as bus, streetcar, subway, or train, minimizing automobile dependence. Walking and bicycling are now seen as essential ingredients in an integrated, intermodal transportation system to give travelers transportation options and to provide continuity from home to destination. Beyond providing an internally well-connected pedestrian network, it is important to provide connectivity with the larger city and region through convenient and accessible links to other modes such as bus, streetcar, subway, or train within a reasonable time-distance. This means that stations need to be spaced frequently enough to allow pedestrian access for residential and commercial zones, usually ¼ to ½ mile, or a 10 to 20 minute walk. A complete pedestrian network will offer full connectivity between all modes so that one can navigate seamlesslessly from foot to trolley or subway to train or air without difficult breaks. A small pedestrian district, no matter how well designed, cannot contribute to a reduction in automobile use if it is not well supported by transit and situated within an accessible mix of land uses.

3. Land use patterns need to be fine grained and varied, especially for local serving uses, so that pedestrians can actually walk to useful destinations. Studies have indicated that distance to destinations is the single factor that most affects whether or not people decide to walk or to take the car, and is more of a determinant than weather, physical difficulty, safety or fear of crime (Funihashi 1985; Handy 1996; Komanoff and Roelofs 1993). Several studies have found that the distance Americans will walk for typical daily trips is quite limited, ranging from 400 feet to about ¼ mile (Weinstein1996). Untermann found that 70 percent of Americans would walk 500 feet for daily errands and that 40 percent would walk 1/5 mile; only 10 percent would walk ½ mile (Untermann 1984).

A walkable neighborhood or city has an accessible pattern of activities to serve daily needs. This means that one can reach most local-serving uses on foot within 10 to 20 minutes or up to ½ mile. The types of activities that fall within this “neighborhood access” category include shops, cafes, banks, laundries, grocery stores, service stations, day care centers, fitness centers, elementary schools, libraries, and parks. However, most post-industrial development in the U.S. has lost walkability and the necessary fine-grained pattern of uses so that it is impossible in many areas to reach even one everyday activity on foot within ½ mile.

Could a very low density city ever become walkable? Land use intensity and diversity, like connectivity of the path network, are best established at the very beginning of the development process. Once a low density coarse grained pattern is put in place, it is a legal and physical challenge to insert density and variety.

4. The pedestrian network needs to be safe for people of varied ages and degrees of mobility, both from traffic hazards and crime. Perhaps the best understood and most fully developed aspect of walkability is pedestrian safety. In most U.S. cities transportation and land use policies have made walking and bicycling inconvenient, unpleasant, and dangerous. Each year 6000 pedestrians and bicyclists are killed in traffic in the U.S.; pedestrians are 23 times more likely to get killed than automobile passengers (Federal Highway Administration 2003). Environments that maximize fast and efficient auto travel are rarely enjoyable or safe for pedestrians and bicyclists.

A recent trend across the country has been “traffic calming,” techniques for making streets more pedestrian friendly by slowing down traffic through a variety of devices: chokers, chicanes, speed bumps, raised crosswalks, narrowed streets, rough paving, traffic diverters, roundabouts, landscaping, and other means.

5. Pedestrian paths need to be well designed in terms of width, paving, landscaping, signing, and lighting. The quality of the path itself, of course, is essential to walkability. Perhaps the least hospitable pedestrian path is the auto oriented commercial strip, a treeless expanse dominated by several lanes of noisy traffic, polluted air, glaring lights and raucous signs. The street has few, if any, designated crosswalks and is much too wide for a pedestrian to cross comfortably. The chaotic frontage is poorly defined, lined by blank big boxes, large parking lots, and drive-in businesses. Haphazard utility poles and boxes, street lights, traffic control signs, hydrants, mail boxes and parking meters dominate the sidewalk, which is constantly interrupted by driveways to businesses (Southworth and Lynch 1974).

If the strip is pedestrian hell, then the ideal pedestrian path will provide for the comfort and safety of pedestrians of varied ages and physical abilities. It should be continuous, without gaps, and should have a relatively smooth surface without pits, bumps, or other irregularities that could make walking and wheelchair access difficult. It should be at least wide enough for 2-3 people to pass one another or to walk together in groups, and much wider in very urban situations. Terrain can be a significant factor in walkability, especially in cities with snow and ice. Encroachments into the pedestrian right-of-way such as utility poles, mail boxes, or newspaper vending machines can compromise walkability by constricting the pathway or blocking crossings. Landscape elements such as planted verges help insulate the pedestrian from the moving traffic, and street trees provide protection from the sun and help define the street space. Pedestrian scaled path lighting can enhance nighttime walking and provide a greater sense of safety.

6. The path context, including street design, architecture and landscape, needs to offer visual interest and overall explorability. Perhaps the most problematic and least developed of walkability criteria are those related to quality of the path context. A safe, continuous path network in a monotonous physical setting will not invite pedestrians. The path network must engage the interest of the user. Many aspects of the path context can contribute to a positive walking experience: visual interest of the built environment, design of the street as a whole, transparency of fronting structures, visible activity, views, lighting, and street trees and other landscape elements.

The postindustrial city has become an increasingly closed and hidden world as processes of production and marketing are hidden from view. Big box shopping, introverted shopping malls and office parks, vast parking lots and reliance on electronic communications have all contributed to urban landscapes that are difficult to read. A transparent environment allows one to sense the social and natural life of a place through first hand observation. Such qualities are impossible to deal with at the macro scale of most transportation analysis and planning, but require detail design and attention to the special qualities of places. In most large developments of mass produced housing, repetitive architecture and uniform street designs devoted to the automobile have produced neighborhoods with little pedestrian appeal.

In the past century a few notable exceptions to the general trend of post war development have sought ways of maintaining pedestrian access, while accommodating the automobile. In the 1920s and 30s, Clarence Stein structured his designs for new garden suburbs such as Greendale, Wisconsin and Radburn in Fairlawn, New Jersey around a continuous green core with pedestrian and bicycle paths that connected homes with school, local shops, and transit. In Britain in the 1960s, Gordon Cullen and others developed plans to restore or reinvent the traditional townscape as an engaging “sequence of revelations” for the pedestrian (Cullen 1961). The idea is still alive, although not commonly seen, in places like Village Homes in Davis, California and Reston, Virginia. Many New Urbanist developments emphasize walkability, as well. In The Kentlands in Gaithersburg, Maryland particular design attention was given to creating pedestrian scaled streets with varied architecture and landscape. Small-scale detail along the streets, as well as changing vistas and focal points from neighborhood to neighborhood make it an enjoyable place to go for a walk. Every district has numerous alternate pathways. It has been so successful in this regard that people drive to it from other suburbs just to take a walk (Southworth, 1996). In all of these cases walkability has been an important feature, but regrettably each of the developments is a rather small, auto dependent island stranded in motopia.

There is no general theory of spatial design for the pedestrian environment that applies everywhere. Although many urban designers have attempted to develop formulas for street width, setbacks, or ratios of enclosure height to street width, for every rule that is made, examples of successful streets can be found that break the rule. The canyon streets of Manhattan are often perceived as attractive and walkable, as are the small seventeenth century lanes of Marblehead, or the broad tree-canopied boulevards of the Country Club district of Kansas City. Street trees and other vegetation almost always enhance walkability, but several European examples immediately come to mind that violate this ideal such as the treeless, arcaded streets of Bologna or the stone streets of Venice, Florence and Sienna. Here the architecture, street space, and street life provide the interest and engage the pedestrian in exploration. Many U.S. neighborhoods such as streetcar suburbs built from the 1880s to 1920s are rather nondescript architecturally, but still have a high degree of walkability. They are valued for the comfortable scale of the streets and blocks, the canopy of street trees, the variety of architectural expressions, and the connection of buildings to the street.

Successful approaches will vary by culture, place, and city size. Nevertheless, a few attributes are likely to contribute to the quality of path context in most urban and suburban settings: scale of street space, presence of street trees and other landscape elements, views, visible activity and transparency, scale and coherence of built form. The important thing is to engage the pedestrian’s interest along the route.


WALKABLE SUBURB2It will not be easy to achieve walkable cities in the U.S., especially since more than half of the typical American metropolis has been built according to automobile dominated standards. There may be resistance to improving things for the pedestrian or bicyclist, fearing space will have to be taken away from the car. Often it is more difficult to retrofit built-up areas because the patterns are already established. While it is not impossible to retrofit existing street networks to serve pedestrians and to insert some density and mixed uses into low density cities, it will require imagination and persistence.

To create the walkable city in the automobile age, emphasis will need to shift from almost total auto orientation, to acceptance and promotion of pedestrian and bicycle access at all levels. The regulatory environment will need to shift toward encouragement of walkability, and the design and planning professions will need to work toward creation of integrated pedestrian access at all scales of movement. The tasks are challenging but the benefits for urban life will be substantial. A focus on the walkable city will transform the way we live in fundamental ways, benefiting health, social relations, and the natural environment.


I am grateful for the assistance provided by Raymond Isaacs, Sungjin Park, and Jeff Williams.

For a more detailed discussion of this subject see: Southworth, Michael, “Designing the Walkable City,” Journal of Urban Planning and Development, Fall 2005.


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