Browsing by Subject "Cities"

Now showing 1 - 12 of 12

Bicha space-time : queer and trans femme spatial practices in Sobral, Ceará
(2023-04-21) Rojas, Joseph Luis, Jr.; Leu, Lorraine
Despite prevailing stereotypes that construct the Brazilian Northeast and non-metropolitan urban spaces as anachronistic and conservative, queer and trans people in a growing number of cities such as Sobral, Ceará, have managed to project themselves onto local, regional, and (trans)national imaginaries. Inspired by Dora Silva Santana’s concept of Afro trans vivências, this thesis centers bicha vivências nordestinas (Northeastern bicha living), understood as the embodied knowledge and resistance of Northeastern queer and trans femmes. I follow a group of college-aged sobralenses primarily consisting of (effeminate) gay men, drag queens, and non-binary and transfeminine folks, and examine the ways in which they adeptly navigate and negotiate different parts of the city in an effort to appropriate spaces for queer and trans sociability. I argue that they queer or trans-form space in Sobral, producing what I call transient geographies, through public performances of femininity and gender nonconformity made possible by fleeting but recurring assemblages of queer people in relationship. I also narrate the embodiments and performances of Rawser, a non-binary gay drag queen who sings in the historically macho genre of forró, and Malika, a black trans artist who translocalizes cultural forms such as ballroom and slam poetry. I argue for techniques of transfemmation as a framework for understanding the methods or tactics by which ephemeral performances of femininity and gender non-conformity, such as those modeled by Rawser and Malika, may queer or trans-form space. Collectively, my interlocutors complicate standard depictions of the region, contest social norms, disrupt the expected uses of (symbolic) space, and demonstrate some of the creative ways in which queer and trans femme spatial practices work within, alongside, and against otherwise cisheteronormative geographies.
Cairo ecologies : water in social and material cycles
(2014-05) Farmer, Tessa Rose; Ali, Kamran Asdar, 1961-
This dissertation investigates the ways in which the natural and the social overlap in the symbolic center of human activity, cities. Cities are full of living organisms, existing not in a perfect state of equilibrium but rather in states of constant flux. The cycles of life moving through the city of Cairo, Egypt are dependent on water as a vital component and scarce resource in systems of biological exchange, as well as one among many pieces of infrastructure that the city requires to survive. This dissertation looks at the informal systems that residents of a squatter settlement in Cairo, Egypt called Ezbet Khairallah have created to make life possible, as well as their attempts to get the state to formally provide these services; work that is done at collective scales and in everyday practices. The dissertation also looks at what happens when areas such as Ezba are successful in getting the state to recognize them and institutionalize utility services, what the hidden costs and unintended consequences are of becoming formal end users of state systems. The dissertation provides an overview of the forces at work in shaping Cairo, highlighting the rural to urban migration patterns and shifting urban policy over the course of the 20th century that have funneled so many into informal housing settlements. In addition, the dissertation highlights the particular material history of Ezbet Khairallah, and how that has shaped the social and material circumstances of residents. It examines the material and affective implications of being unable to escape waste, of bodies that bear signs of systems that both make life possible and make life difficult. By studying the institutional framework in which these questions get worked out in Egypt, we can better situate the struggles of those living in the urban margins of the global south, such as those in Ezbet Khairallah.
Invisible presence, the confusion of an artist in the city
(2019-05) Bahrehmand, Nima; Williams, Jeff, M.F.A.
Cities are Critical sites. In my art practice, I stroll through a landscape. I examine the inhabitants of the land, their dreams, and the structures inhibiting those dreams. My aim is to challenge the status quo and imagine new possibilities of existence. Invisible-presence is a series of ongoing art projects aimed at the study of societies through an artistic framework. The project focuses on the confrontations that arise between modern societies and their citizens. Cities control social interactions and behaviors, through surveillance and policies that guide, direct and impede urban planning. Structures of power dictate our direction of movement through the implementation of codes that are as visible as street signage and fences that prevent crowds from congregating. My Artwork looks at the citizens who challenge these parameters.
Microsimulation of household and firm behaviors : coupled models of land use and travel demand in Austin, Texas
(2007-12) Kumar, Saurabh, 1983-; Kockelman, Kara
Households and firms are key drivers of urban growth, yet models for forecasting travel demand often ignore their dynamic evolution and several key decision processes. An understanding of household and firm behavior over time is critical in anticipating urban futures and addressing transportation, land use and other concerns. Birth and death, migration and location choice are defining events in a household's and firm's life cycle, and a study of household and firm evolution requires the estimation and application of models for each of these. Such an exercise is hindered primarily by a lack of quality micro-data. This thesis develops a basic framework for modeling household and firm demographics using microsimulation. Year 2005 zonal household population and employment point data for the Austin, Texas region, coupled with various, more aggregate data sets, are used to simulate household and firm evolution over time and space. The model consists of household evolution, firm evolution, location choice and travel demand models. Household and firm simulation models are run at one-year time steps, in order to forecast Austin's future. The household simulation component is made up of models for birth (of children and of households), death of individuals (and other forms of household dissolution), migration, children leaving home, vehicle ownership, and location choice. These models are estimated using multinomial logit and Poisson specifications. The firm simulation component consists of firm birth, death, growth and location choice models. A Markovian process is assumed in order to anticipate firm growth and contraction (across firm-size categories), along with logit and Poisson model specifications for firm location choice. Firms are categorized based on number of jobs (6 categories) and industry sector (4 sectors) they belong to. Austin's household and commercial vehicle travel survey data were used to estimate trip generation and distribution models. Simulation results for multiple growth-rate scenarios suggest a roughly 180% increase in the Austin population over a 30-year period, 210% increase in vehicle ownership, a 230% increase in jobs, and more than a 300% increase in vehicle-miles traveled. When a 10-cent/mile flat-rate toll is applied over all links, the year 2035 VMT is predicted to be just 3% less than under the no-toll scenario. A fixed toll of 10-cents-per-mile shows a very low impact on VMT over a 30 year period than expected. To ensure a jobs-worker balance, the model may well merit greater synchronization of the population and firm synthesis models. The simulations also suggest a clear shift of firms and households towards more central zones, in part because of the cross-sectional nature of the data sets used to calibrate the location choice models and the lack of density restrictions or other reflections of land-availability constraints on new development. Essentially, households and firms exhibit a strong centralizing tendency, that Austin's land market simply cannot allow, due to space and other constraints on new building. Explicit expressions of such constraints should prove helpful in future implementations of this work. While microsimulation of urban systems is data and computing intensive, it provides a flexible tool for analyzing the impacts of various policy decisions as well as other, demographic, environmental and system changes. It allows transportation planners explore the potential responses of individuals to changes in their environments and predict the long-term implications of policy decisions. This thesis seeks to be a bridge for further integrated travel demand and land use models of this type.
Operations research models of technology transitions and the role of policy support
(2020-05-05) Brozynski, Max Tomasz; Leibowicz, Benjamin D.; Bickel, James E; Hasenbein, John J; Olmstead, Sheila; Webber, Michael E
Technology exists to fulfill functions in society, and technological innovations are continuously proposed to fulfill a particular function more effectively than an incumbent technology. These innovations are disseminated through society in a process called technology diffusion, and may ultimately replace an incumbent system in what is known as a technology transition. Due to the complex and uncertain underlying processes of technology adoption and diffusion, technical systems are resistant to transition to possibly superior alternatives. To address market, systemic, and structural failures preventing a desired technology transition, a policymaker, or other motivated agent, may strategically intervene to stimulate or accelerate the diffusion process. The success or failure of such policy intervention carries crucial implications for climate change mitigation, healthcare advances, and any other aspect of society that technology touches. However, existing models of optimal technology policy design omit or otherwise offer crude representations of these underlying processes and are largely case-specific at the expense of gleaning generalizable insights. The goal of this dissertation is to advance the operations research modeling of technology transitions and the role of policy support. Through a variety of powerful operations research methodologies and relevant case studies, the individual projects in this dissertation offer novel models of technology transitions and insights into real-world technology policy, especially in the energy and climate domain. The three core chapters of this dissertation begin with the development of an applied energy system optimization model to assess a real-world climate policy, then move on to present two novel theoretical models that yield more general, analytical insights into technology policy decision making. Chapter 2 addresses the growing importance of cities in climate change mitigation with the development of an energy system optimization model for urban-scale decarbonization. Our optimization model determines the least-cost power and transportation technology pathways to achieve a policy goal of net-zero greenhouse gas emissions and is used to analyze the Community Climate Plan adopted by Austin, Texas. We find that the policy objective can be achieved at a modest 2.7% increase in net present power and transportation costs relative to business-as-usual. The optimal decarbonization pathway proceeds through two distinct stages, first reducing power sector emissions, then electrifying transportation. Solar PV expands in the long run with or without the climate plan based on favorable cost projections, but the policy causes wind to replace natural gas as a complement to solar PV. Our findings also highlight the substantial value of intelligently scheduled battery storage operations and electric vehicle charging. While the energy system optimization model of Chapter 2 captures numerous decisions for a complex urban energy system, it carries limiting assumptions about how technology diffusion occurs and the role of a policymaker in supporting a technology transition. Addressing these larger questions motivates the project in Chapter 3, which describes the development of two stylized models of technology policy decision making under uncertainty. The first model is a Markov reward process (MRP) that represents policy interventions with one-time, upfront costs, while the second is a Markov decision process (MDP) that represents interventions with recurring costs. For each model, we derive analytical expressions for the policymaker's willingness to pay (WTP) to raise the probabilities of advancing a technology development or diffusion process at various stages and compare and contrast the behaviors of the MRP and MDP models. Most notably, our analytical findings elucidate how the different cost-accounting schemes and the possibility of regressing from a more advanced development or diffusion stage back to an earlier one affect the WTP. Then, we conduct numerical sensitivity analysis to explore how the optimal technology policy portfolio varies with certain parameters, and present a case study on lithium-ion batteries for electric vehicles to demonstrate the practical application of our model to technology policy decision making. In Chapter 4, we narrow our focus on technology transitions to infrastructure-dependent technologies common in energy, transportation, and telecommunications systems. Policymakers seeking to promote the diffusion of infrastructure-dependent technologies are often confronted with the chicken-and-egg problem: consumers are reluctant to adopt the technology without adequate infrastructure available, and firms are reluctant to invest in infrastructure without a sufficient number of adopters. This chicken-and-egg problem can hinder the diffusion of new technologies and prolong the timeframe over which existing technological systems remain locked-in. In this paper, we formulate a stylized model of technology policy decision making from the perspective of a policymaker who seeks to stimulate the market penetration of an infrastructure-dependent technology. Our model is a bilevel optimization problem in which a policymaker (leader) maximizes net social benefits by setting the levels of two incentives: a subsidy for a profit-maximizing firm (follower) to invest in infrastructure that raises the benefit of adoption to consumers, and a direct subsidy for consumers to adopt the technology. We analytically derive the firm's optimal infrastructure investment response to the upper-level policy decisions, and show that the bilevel model is equivalent to a quadratic program. To bypass non-convexity, we develop a custom solution strategy based on decomposition, and find that it performs better than directly applying an off-the-shelf solver to the potentially non-convex problem. Finally, we present a case study on the diffusion of battery electric vehicles and obtain insights into how a policymaker should allocate resources to charging infrastructure and vehicle incentives. The three projects of this dissertation employ operations research methods to model technology transitions and the role of policy support. While each captures a variety of phenomena affecting technology transitions and optimal technology policy decision making, there remain thought-provoking questions that future research can address. We conclude this dissertation with proposed research directions and contemplate the high-level, real-world implications of this work.
Optimal decarbonization pathways for urban residential building energy services
(2018-06-27) Lanham, Christopher Mills; Leibowicz, Benjamin D.
Climate change and its associated threats to societal welfare are largely attributable to energy consumption and greenhouse gas emissions. As a major consumer, the residential buildings sector accounts for a significant portion of GHG emissions, and both consumption and emissions are projected to increase throughout the coming decades. Energy in residential buildings is demanded in several major service categories including space heating, space cooling, water heating, lighting, refrigeration, cooking, and miscellaneous plug loads. Drivers of household demand in each service category include factors related to climate, income, demographics, and urban form. Strategies for decarbonizing building energy services can broadly be divided into three classes: (1) switching to lower-carbon fuels in the energy supply mix; (2) adopting more efficient energy end-use appliances within residential buildings; and (3) improving the thermal energy efficiency of the buildings themselves. While the demand-side interventions belonging to (2) and (3) are thought to be the lowest-cost decarbonization options, they tend to be underrepresented in energy system models relative to supply-side strategies. This study evaluates energy system transformation pathways under climate policy and building stock scenarios for the residential sector in Austin, Texas through 2050. The objective is to evaluate the economic cost of decarbonization given assumptions about building stock efficiency while assessing how technology mixes should shift over time to most cost-effectively achieve a predetermined emissions reduction goal. Four building efficiency scenarios are considered under both a no policy scenario and a climate policy. The model optimizes investments and operations of supply and end-use technologies under the various building stock and climate policy scenarios to meet annual and daily demand requirements in each service demand category at least cost. Model outputs include technology capacity mix by demand category, energy and carbon intensity of service demands, and net present costs of optimal system transformations. The results demonstrate a strong synergy between decarbonization of the upstream generation mix and electrification of the end-use service categories. Efficiency improvements to natural gas-fueled technologies have benefits in the interim but play a limited role in deep, long-term decarbonization efforts. Improved building thermal efficiencies have significant cost-saving potential, as implementing a climate policy with the building stock evolving toward the LEED Gold efficiency level results in a lower net present cost than the unconstrained case with no improvement in building thermal efficiency.
The Philosophy of Sustainable City Design
(2020-05) Harries, William G.
Sustainable cities are not only a desirable future but a necessary one yet we still haven’t achieved fully sustainable cities. We have the technological and economic means to create sustainable cities but attempts like Masdar City in the United Arab Emirates have failed to meet their potential. To create a sustainable city we also need to have harmony between the three E’s of sustainability: environment, economy, and equity. The most essential element of sustainability isn’t one of these E’s though, it is community. Community is the thing that holds these principles together and without it, a city cannot succeed. We need more than just a successful community though, we need sustainable design to support the community and vise-versa.
Planning healthy cities for immigrant populations
(2022-05-05) Khan, Yuhana; Sletto, Bjørn; Solis, Miriam
Austin is a rapidly growing city and an emerging gateway for immigrants. While Mexico is still the largest contributor of immigrants, there has been a gradual increase of immigrants from Asia and Africa as well. Austin is part of the welcoming communities movement that “seek to have long-time residents and recent immigrants work together to create stronger communities” (Wasem et al, 2021). The concept of healthy cities has existed for some time now – it attracts people to settle down in a place that provides for their wellbeing. However, what challenges arise for cities that are experiencing rapid demographic changes? In this report, the primary focus is the needs of a growing immigrant population in Austin. By examining the intersection of planning for healthy cities and the growing number of immigrants with specific needs, this report will explore the following research question: How do healthy city initiatives in Austin and in other cities consider and incorporate the specific needs of migrant communities? This population needs specific considerations at the beginning of their journey in a foreign land and even the years to come. We have yet to see this be a common topic discussed, although it has made headway in city departments. This report will investigate Austin’s healthy city initiatives and how they integrate the immigrant community. Austin falls into the category of developing cities with major population increases, including immigrants. I will include context on other cities’ experiences implementing healthy city initiatives to understand the lessons learned for Austin and vice versa. The purpose of this report is to recommend ways to incorporate the specific needs of immigrants into Austin’s healthy cities initiatives.
Remaking urban worlds : New Delhi in the time of economic liberalization
(2011-05) Mehra, Diya; Visweswaran, Kamala
This dissertation examines the impact of neoliberal economic reform on New Delhi's urban landscape. It shows how the city has transformed since 1991 through two distinct, but interlinked processes: firstly massive 'upgradation' and place-marketing efforts, initiated and supported by the state, to create for the city a global identity worthy of the capital of a newly resurgent and aspirational nation, one that is also welcoming to new capital flows and forms as Delhi undergoes massive spatial, and economic expansion. Secondly, neoliberal urban development is also marked by a series of mass evictions of the city's existing informal, indigenous economy as degraded urban forms. In tracking the unfolding 'worlding' of the city, the dissertation is interested in the production of locality at the scale of the city, the ways by different sites, networks and neighborhoods articulate with the process, and how locality is produced through a series of inclusions and exclusions. In the first half of the dissertation, the focus is the conjectural emergence of conditions of transformation, mainly through the articulation of state urban renewal policies which promote privatized urban development, judicial eviction orders and media circulated calls for the building of a new 'upgraded' city to replace the old. This, as a new 'globalized' and aestheticized imaginary of the nation, city and its citizens takes shape. In the second half, the dissertation examines shows how upgradation and mass eviction have played out in Delhi neighborhoods, juxtaposing the experience of middle class areas, who's activism has been vital in putting forth a new vision of the city, with two cases of displacement. These are the demolition of the city's slums, and secondly the sealing or closure of large networks of indigenous/informal traders. In all three cases, the dissertation outlines ethnographically how residents receive, perceive and negotiate changes in relation to their memories, habitus, and local knowledges of the old, and how they engage with state and political actors, judicial fiat, party politics and the structures of the city's mass democracy to encourage or oppose urban reforms. In its conclusion, it argues that upgradation and eviction notwithstanding, activism across classes has engendered a common critique of governance among residents.
The intersecting aesthetics of crossed borders : Albrecht Dürer’s ideal city plan and the 1581 Native map of Cholula
(2022-06-02) Marino, Allison; Smith, Jeffrey Chipps, 1951-
Many know Albrecht Dürer (1471-1528) for his expertly rendered woodcuts and treatises on art and perspective. Fewer know him for his work as an urban planner, a role evidenced by his plan for an ideal city contained within his fortification treatise of 1527. It is through this plan that we gain a unique understanding of the artist’s perception of the socio-political environment in which he worked, which was made tumultuous by the uncertainties of the Reformation and the recent Peasants’ Revolts. In this paper, I propose a new approach to understanding the formal elements that characterize Dürer’s ideal city plan: analyzing the visual congruities between it and the Native-made Relaciones map of Cholula from 1581. Examining how squareness, order, and centrality functioned in these maps, which were produced as direct responses to distinctly urgent socio-political stimuli, as means of promoting the productivity and cooperation that characterized these towns, provides a deeper understanding of the inherent motivations for and effects of these artistic techniques.
Two crises, one stone : using existing building stock to help combat the housing and sustainability crises
(2023-05) Gilk, Samantha; Holleran, Michael
Housing has been and most likely will continue to be a complicated and existing topic as long as the population continues to grow as it does. Historically middle density housing has been used as infill in neighborhoods or close to historic downtowns. In recent decades, however, this middle density housing has been greatly ignored for high- and mid-rise apartment complexes and sprawling suburban single family homes. The topic of housing has also entered a contradictory circle. On one hand cities across the United States are in desperate need of housing, especially affordable housing. But on the other hand, the existing natural resources across the world are in desperate need of less building and less sprawl. How do you balance these two conflicting needs? Enter adaptive reuse. By combining adaptive reuse projects and housing projects we can add to the middle density stock while maintaining important cultural fabric in the preservation of vernacular buildings. This paper is going to discuss the benefits that are inherent in both adaptive reuse and middle density housing as separate entities as well as how these two ideas naturally fit together and how more projects of this nature can be promoted. Lastly, several case studies will be examined to see how these types of projects already exist and how they have achieved their current states.
Urban aerosol : role of sources and atmospheric processes
(2022-08-30) Gani, Shahzad; Apte, Joshua S.; Passalacqua, Paola; Kinney, Kerry A; Hildebrandt Ruiz, Lea
Outdoor air pollution has detrimental health effects resulting in substantial global and regional decrements in life expectancy. More than half of the world's population lives in urban areas making it important to understand the sources and processes that drive urban air pollution. Some of the most polluted cities in the world are in India and as of 2019, Delhi is the world's most polluted megacity. While cities in the USA generally have an order of magnitude lower aerosol mass loadings than those observed in Delhi, particle number (PN) concentrations often tend to be similarly high. In this dissertation, I provide the overview of the Delhi Aerosol Supersite (DAS) study--a site that we set up in Delhi for long-term continuous online aerosol composition and size distribution measurement using state-of-art instruments. In Chapter 2 and 3 of this dissertation, I investigate the aerosol composition and aerosol size distribution observed in Delhi respectively. I also use long-term fixed site and mobile monitoring datasets to investigate the spatiotemporal variation of ultrafine particle (UFP, D [subscript p] <100 nm) concentrations in the San Francisco (SF) Bay Area, USA. For both Delhi and the SF Bay Area, I have distilled insights on physicochemical processes on the basis of field observations complemented with satellite and modeling datasets. Delhi, India routinely experiences some of the world's highest urban particulate matter concentrations. We established the DAS study to provide long-term characterization of the ambient submicron aerosol composition in Delhi. In chapter 2, we report on 1.25 years of highly time resolved speciated submicron particulate matter (PM₁) data, including black carbon (BC) and non-refractory PM₁ (NR-PM₁), which we combine to develop a composition-based estimate of PM₁ ("C-PM₁" = BC + NR-PM₁) concentrations. We observed marked seasonal and diurnal variability in the concentration and composition of PM₁ owing to the interactions of sources and atmospheric processes. Winter was the most polluted period of the year with average C-PM₁ mass concentrations of ~210 μg m⁻³. Monsoon was hot and rainy, consequently making it the least polluted (C-PM₁ ~50 μg m⁻³) period. Organics constituted more than half of the C-PM₁ for all seasons and times of day. While ammonium, chloride and nitrate each were ~10% of the C-PM₁ for the cooler months, BC and sulfate contributed ~5% each. For the warmer periods, the fractional contribution of BC and sulfate to C-PM₁ increased and the chloride contribution decreased to less than 2%. The seasonal and diurnal variation in absolute mass loadings were generally consistent with changes in ventilation coefficients, with higher concentrations for periods with unfavorable meteorology--low planetary boundary layer height and low wind speeds. However, the variation in C-PM₁ composition was influenced by temporally varying sources, photochemistry and gas-particle partitioning. During cool periods when wind was from the northwest, episodic hourly averaged chloride concentrations reached 50-100 μg m⁻³, ranking among the highest chloride concentrations reported anywhere in the world. We estimated the contribution of primary emissions and secondary processes to Delhi's submicron aerosol. Secondary species contributed almost 50-70% of Delhi's C-PM₁ mass for the winter and spring months, and up to 60-80% for the warmer summer and monsoon months. For the cooler months that had the highest C-PM₁ concentrations, the nighttime sources were skewed towards primary sources, while the daytime C-PM₁ was dominated by secondary species. Overall, these findings point to the important effects of both primary emissions and more regional atmospheric chemistry on influencing the extreme particle concentrations that impact the Delhi megacity region. Future air quality strategies considering Delhi's situation in both a regional and local context will be more effective than policies targeting only local, primary air pollutants. While fine particulate matter (PM [subscript 2.5]) mass concentrations in Delhi are at least an order of magnitude higher than in many western cities, the PN concentrations are not similarly elevated. Here we report on 1.25 years of highly time resolved particle size distributions (PSD) data in the size range of 12-560 nm. We observed that the large number of accumulation mode particles--that constitute most of the PM [subscript 2.5] mass--also contributed substantially to the PN concentrations. The UFP fraction of PN was higher during the traffic rush hours and for daytimes of warmer seasons--consistent with traffic and nucleation events being major sources of urban UFP. UFP concentrations were found to be relatively lower during periods with some of the highest mass concentrations. Calculations based on measured PSD and coagulation theory suggest UFP concentrations suppression by a rapid coagulation sink during polluted periods when large concentrations of particles in the accumulation mode result in high surface area concentrations. A smaller accumulation mode for warmer months result in increased UFP fraction, likely owing to a comparatively smaller coagulation sink. We also see evidence suggestive of nucleation which may also contribute to the increased UFP proportion during the warmer seasons. Even though coagulation does not affect mass concentrations, it can significantly govern PN levels with important health and policy implications. Implications of a strong accumulation mode coagulation sink for future air quality control efforts in Delhi are that a reduction in mass concentration, especially in winter, may not produce proportional reduction in PN concentrations. Strategies that only target accumulation mode particles (which constitute much of the fine PM [subscript 2.5] mass) may even lead to an increase in the UFP concentrations as the coagulation sink decreases. The health risks of UFP exposure are an important subject of current investigation in air pollution epidemiology. In the absence of routine monitoring of UFP, air pollution epidemiology studies often use other co-emitted pollutants as proxy for UFP, with NO [subscript x] (NO+NO₂) considered a good choice. In chapter 4, we use long term fixed site measurements along with extensive mobile monitoring data to evaluate the spatiotemporal correlation of UFP and NO [subscript x]. We incorporate 4-6 years of hourly PN concentration data from multiple fixed sites across the San Francisco Bay Area that include near-highway, urban, suburban and rural sites. In addition, we incorporate observations from a 32-month mobile monitoring campaign comprising >3,000 h of coverage of a range of road types and land uses. Across all fixed sites, PN measurements show prominent mid-day peaks during the summer--characteristic of new particle formation--which are not observed for other co-emitted pollutants (NO subscript x], BC, CO). While we found moderate correlation in diurnal patterns of NO [subscript x] and UFP at sites with high traffic, the correlation dropped significantly for low traffic areas--especially during high insolation (e.g., summer daytime) periods. Mobile monitoring data yielded similar results: NO [subscript x] was observed to have weaker correlations with UFP for non-highway roads during high insolation periods. The spatiotemporal profiles of UFP can differ strongly from other traffic-related air pollutants when new particle formation from nucleation contribute to a significant fraction of UFP.