Impact Of Urban Form Research Articles

The impact of urban form on commuting in large Chinese cities

Studies on cities in Europe and the United States have demonstrated that travel behaviour is influenced by urban form. Based on these findings policies steering the shape of cities have been proposed to reduce urban transport emissions and limit congestion. Such policies can also be relevant for the rapidly growing and motorising Chinese cities. Yet, empirical evidence on the relationships between urban form and car usage is scarce for the specific Chinese context that is characterised by high densities, fast development and strong government steering. Using novel crowd-sourced datasets we study the impact of several urban form variables (city size, urban density, land-use mix, polycentricity and spatial clustering) on the cost of commuting expressed in time and distance. The results show that city size and spatial clustering are important determinants of commuting: large cities without clear clusters of businesses and other facilities have longer average commuting times and distances. Increased prosperity also adds to longer and lengthier commutes. Spatial planning measures that maintain or reinforce high-density clusters can help limiting commuting distance and time. Current sprawled urban development may have long-term, negative consequences for the accessibility and liveability of Chinese cities and could hamper their economic potential.

The impact of urban form and gasoline prices on vehicle usage: Evidence from the 2009 National Household Travel Survey

This paper relies on generalized structural equation modeling (SEM) to tease out the relationship between land use, gasoline prices and travel behavior. We analyze data from a Southern California subsample of the 2009 National Household Travel Survey (NHTS), which has a quasi-experimental nature thanks to large exogenous variations in gasoline prices during the administration of the NHTS (March 2008–April 2009). Our joint models of residential urban form, vehicle efficiency choice, and vehicle use account for residential self-selection and endogeneity of vehicle preferences in order to explain vehicle miles traveled (VMT) for both work and non-work trips. Residential urban form is treated as a latent construct that reflects observed variables such as population density, land use diversity and distance to employment centers. We find that in the short run, households drive 0.171% less for non-work trips when gas prices increase by 1%, while work trips are not responsive to gasoline price changes. Moreover, owners of more fuel efficient vehicles tend to be more educated and Asian. In addition, households in lower density neighborhoods are more likely to have a higher income, to be older than 65 and White; these households tend to own more vehicles per driver. Overall, our results underscore the importance of accounting for the nature of trips when estimating the short-term price elasticity of travel.

Industrial Risks Impacts on Urban Ecosystems of Algerian Cities, Case of Study: Skikda City

The day after the independence, Algeria has faced the problems of underdevelopment and consequently the choice of model economic and social development. Through the exceptional resources hydrocarbons, the country has opted for a basic industry in which the petrochemistry and steel industries are the backbone.This work is in the field of research on the link between architecture, urban and industrial risks. Where we will discuss the report and the link between urban forms, architectural ones and urban industrial risks.The city of Skikda is our case of study with the implantation of petrochemical pole that has been done next to the city, at a time when the concept of industrial risks does not exist and where urbanization is carried out under conditions that do not take into account the impact of the petrochemical industry on humans and the environment.In fact, the impact of urban forms on insecurity is high. Shape influences security issues and industrial risks, not only by how it takes. However, it also determines the options.

Impact of Urban Form on Energy Use in Central City and Suburban Neighborhoods: Lessons from the Phoenix Metropolitan Region

Urban form, land use patterns, and the type of structures significantly influence a city's energy needs, and consequently, its greenhouse gas (GHG) emissions. This study aims to clarify connections between urban form and its use together with the associated energy demands for infrastructure (buildings and paved surfaces) and transport. The model is tested through case studies of two Phoenix sub-areas, one in downtown Phoenix, which is undergoing redevelopment towards higher density housing and the second, a low-density suburban area at the edge of Phoenix, which has undergone significant growth in the last two decades. The results indicate that older inner city areas continue to have the lowest energy demands and carbon emissions per capita compared to other neighborhoods examined. The low-density areas in the inner city and in the newer suburbs have almost equal amounts of energy demands per capita. However, the bulk of the energy demands in the newer suburbs is related to the transportation infrastructure while the older low-density neighborhoods have higher energy intensive residential structures.

The impact of urban form on CO2 emission from work and non-work trips: The case of Beijing, China

A critical issue in the mitigation of transport CO2 emission and the development of low-carbon cities is the need to get a better understanding of factors that shape travel behavior, and resulting carbon emission. Using an activity diary survey and GIS-based land use data in Beijing, this research investigates how urban form characteristics at neighborhood and city scales impact individual's daily travel behavior and subsequent CO2 emission from work and non-work trips, respectively. Structural equation modeling (SEM) is adopted to examine the relationship between urban form, travel behavior, and CO2 emission, while accounting for residential self-selection and socio-demographic attributes. Results show that residents living in neighborhoods with higher job density, proximity to an employment sub-center and greater subway accessibility tend to travel shorter distance, choose low-carbon travel modes, and emit less CO2 from work related trips. People resident in neighborhoods with higher retail density or mixed land use tend to travel shorter distance and have less CO2 emission from non-work trips. The research also suggests that work related trips have larger variation than non-work trips across neighborhoods, indicating the job-housing spatial mismatch might be the main factor that drives up travel demand and transport CO2 emission in urban Beijing.

Impact of Urban form on Energy Use in Water Distribution Systems at the Neighbourhood Level

This paper examines the relationship between urban form and the energy consumption of water distribution systems at the neighbourhood level. Neighbourhood scenarios were developed based on a combination of street topologies and population densities. Energy use in this investigation was analyzed in two components – the pumping energy needed for operation and the embodied energy required for the fabrication, transportation, and initial installation of pipes. Results showed that the physical topology of traditional gridiron neighbourhoods resulted in lower embodied and pumping energy requirements than warped parallel and cul-de-sac/loop neighbourhoods.

The impact of urban form on travel behaviour in three Baghdad neighbourhoods affected by terrorism

The article examines: 1) how travel behaviour was influenced by urban form in three terrorism-affected Baghdad districts; and 2) how the responses to terrorism in these neighbourhoods affected travel behaviour. The results suggest that urban form can mediate the impacts of terrorism and counter-terrorism with traditional urban form districts being more resilient than modern high-rise districts.

The Effect of Urban Form and Residential Cooling Energy Use in Sacramento, California

The impact of urban form on residential space-conditioning energy use has been controversial in recent planning literature. This study empirically evaluates the association between urban form and residential energy use, focusing particularly on residential electricity use for space cooling in the City of Sacramento, California. We characterize urban form, property conditions, and demographic and socioeconomic characteristics by applying spatial metrics embedded within a geographic information system where LiDAR data effectively include each building and the surrounding vegetation. A statistical model is applied to assess the relationship between these explanatory variables and the estimated summer air-conditioning energy use. Controlling for other variables, higher population density, east—west street orientation, higher green space density, larger vegetation on the east, south, and especially the west sides of houses, appears to have statistically significant effects on reducing summer cooling energy use. This study quantifies the built environment impact on the energy demand of air conditioning and informs planners as they craft urban planning and design policies for energy conservation.

A simplified framework to assess the feasibility of zero-energy at the neighbourhood/community scale

Zero-energy buildings (ZEBs) are attracting increasing interest internationally in policies aiming at a more sustainably built environment, the scientific literature and practical applications. Although “zero energy” can be considered at different scales (e.g., community, city), the most common approach adopts only the perspective of the individual building. Moreover, the feasibility of this objective is not really addressed, especially as far as the retrofitting of the existing building stock is concerned. Therefore, this paper aims first to investigate the opportunity to extend the “zero-energy building” concept to the neighbourhood scale by taking into account two main challenges: (1) the impact of urban form on energy needs and the on-site production of renewable energy and (2) the impact of location on transportation energy consumption. It proposes a simplified framework and a calculation method that is then applied to two representative case studies (one urban neighbourhood and one rural neighbourhood) to investigate the feasibility of zero-energy in existing neighbourhoods. The main parameters that act upon the energy balance are identified. The potential of “energy mutualisation” at the neighbourhood scale is highlighted. This paper thereby shows the potentialities of an integrated approach linking transportation and building energy consumptions.

The effect of urban morphology on urban heat island in the city of Biskra in Algeria

The objective of this study is to assess the impact of urban morphology upon the air temperature variation of urban condition in hot and dry climate of Biskra city in the south east of Algeria. A set of field measurement is performed using thermocouple equipments. A total of five measuring stations, representing different urban morphologies, are chosen in the city centre of Biskra to assess quantitatively the level of UHI and to investigate the overall impact of urban forms on this urban heat island. The results show that UHI phenomenon is becoming the character of the urban micro-climate in the city of Biskra.

Transportation Greenhouse Gas Emissions and its Relationship with Urban Form, Transit Accessibility and Emerging Green Technologies: A Montreal Case Study

This research aims at estimating a GHG emission inventory at the household level using completely disaggregate trip data and taking into account all emitting modes. The impact of urban form (UF) and transit accessibility (TA) characteristics on household level GHG emissions is then quantified and compared to the impact of the introduction of emerging green technologies. Using a large and representative sample of household diaries, trip-level GHG emissions are estimated by combining different sources of data (origin-destination (OD) survey data, vehicle fleet characteristics, transit ridership data, etc.) and by using modelling tools (traffic assignment and GHGs models). Moreover, UF and TA indicators are developed and combined to generate neighbourhood typologies. A simultaneous equation modelling framework is then implemented to investigate the link between UF, TA, socio-demographics, and travel GHGs, taking into account the well known “self-selection” issue. The potential impact of land use and transit supply strategies with emerging green technological scenarios is then compared. Our findings are consistent with the literature, more specifically we have found that the built environment (BE) attributes are statistically significant (10% increase in density, transit accessibility and land-use mix, results in 3.5%, 5.8% and 2.5% reduction in GHG respectively), number of workers and retirees at the household level play an important role in the contribution to GHG emissions (102% increase by adding one worker and 51% decrease by adding a retiree to the household). Moreover, neighbourhood types represented by the combined effects of UF and TS have important effects on GHGs. Also it is found that by replacing transit fleet by electric trains and hybrid buses, the share of transit GHGs would decrease by 32%. With respect to the private motor-vehicle fleet, if current trends persist, the constant improvement of car fuel consumption economy would reduce car GHGs by 7%. According to our results, the two most efficient strategies to reduce GHGs at the regional and household level seem to be the continuous fuel-efficiency improvement of the private motor-vehicle fleet and the increase of transit accessibility.

The Impact of Urban Wind Environments on Natural Ventilation

The aim of this paper is to illustrate the impact of urban wind environments when assessing the availability of natural ventilation. A numerical study of urban airflow for a complex of five building blocks located at the University of Reading, UK is presented. The computational fluid dynamics software package ANSYS was used to simulate six typical cases of urban wind environments and to assess the potential for natural ventilation. The study highlights the impact of three typical architectural forms (street canyons, semi-enclosures and courtyards) on the local wind environment. Simulation results were also compared with experimental data collected from six locations on the building complex. The study demonstrates that ventilation strategies formed using regional weather data may have a propensity to over-estimate the potential for natural ventilation and cooling, due to the impact of urban form which creates a unique microclimate. Characteristics of urban wind flow patterns are presented as a guideline and can be used to assess the design and performance of natural or hybrid ventilation and the opportunity for passive cooling.

The impact of urban form on downtown stadium redevelopment projects: a comparative analysis of Phoenix and Denver

Prior analyses of stadium-focused economic development efforts suggest these projects are multifaceted in scope and one-size-fits-all approaches are rarely successful. This study builds upon prior analyses of stadium development projects and provides a comparative analysis of two stadium projects in Denver and Phoenix, with a focus on the role urban form has on the opposing outcomes of the two projects. Results suggest urban form has an impact on the prospects for success of these projects and that strategies to deal with the urban form of a city should be incorporated into comprehensive plans to revitalize downtown areas. A consideration of urban form is particularly important for polycentric urban areas where the success of downtown economic redevelopment efforts remains largely unexplored and unproven.

The Impact of Urban Form on Travel Behavior: A Meta-Analysis

A common viewpoint held by many New-Urbanist and Neo-Traditional plan- ners is that characteristics of the built environment, such as population density, mixed land use settings and street configuration, exert a strong influence on travel behavior. The empirical evidence for this relation, however, as portrayed in many primary studies, is somewhat mixed. This paper offers an application of statistical meta-analysis in an attempt to settle the contradictory findings reported in the single studies. The findings reaffirm the role of residential density as the most important built environment element influencing travel choice. The findings also reinforce the land use mixing component of the built environment as being a strong predictor of travel behavior. The findings do not, however, support the most controversial claim of the New Urbanism regarding the role of street pattern configuration in influencing travel behavior.

Impacts of urban form on future US passenger-vehicle greenhouse gas emissions

Urban form – for example, sprawl versus infill development – impacts people's daily travel patterns and annual vehicle-kilometers traveled (VKT). This paper explores how urban form impacts greenhouse gas (GHG) emissions from passenger-vehicles, the largest source of urban transportation GHG emissions. Our research uses a recently published urban scaling rule to develop six scenarios for high- and low-sprawl US urban growth. We develop and apply a Monte Carlo approach that describes ensemble statistics for several dozen urban areas rather than forecasting changes in individual urban areas. Then, employing three vehicle- and fuel-technology scenarios, we estimate total passenger VKT and resulting GHG emissions for US urban areas. Our results indicate that comprehensive compact development could reduce US 2000–2020 cumulative emissions by up to 3.2 GtCO 2e (15–20% of projected cumulative emissions). In general, vehicle GHG mitigation may involve three types of approaches: more-efficient vehicles, lower-GHG fuels, and reduced VKT. Our analyses suggest that all three categories must be evaluated; otherwise, improvements in one or two areas (e.g., vehicle fuel economy, fuel carbon content) can be offset by backsliding in a third area (e.g., VKT growth).

Impact of Urban Form on Energy Use in Water Distribution Systems

The paper explores the connection between the urban form of water distribution networks and their energy use. Urban form corresponds to the network pipe configuration and the spatial distribution of water users. An analytical model is developed to quantify the energy use to fabricate pipes, to repair pipes, to pump water, and to dispose of pipes in a trunk line. Results show that only a 10% reduction in annual per capita energy is achieved in the trunk line by increasing population density from 10 ca∕ha to 275 ca∕ha . The analysis is extended by computing energy use in networks with gridiron, radial, and satellite pipe configurations and uniform, monocentric, and polycentric population distributions. On average, the radial/monocentric combination exhibits the lowest annual per capita energy use. The paper is concluded by discussing changes to the form of cities and water main infrastructure to reduce environmental impact.

The impact of urban form on U.S. residential energy use

While the impact of urban form on transportation energy use has been studied extensively, its impact on residential energy use has not. This article presents a conceptual framework linking urban form to residential energy use via three causal pathways: electric transmission and distribution losses, energy requirements of different housing stocks, and space heating and cooling requirements associated with urban heat islands. Two of the three can be analyzed with available national data. After we control for other influences, residents of sprawling counties are more likely to live in single‐family detached houses than otherwise comparable residents of compact counties and also more likely to live in big houses. Both lead to higher residential energy use. Because of the urban heat island effect, residents of sprawling counties across the nation on average pay a small residential energy penalty relative to residents of compact counties. Implications for urban planning are explored.

The impact of urban form on automobile travel: disentangling causation from correlation

A longstanding question within the field of transportation demand management is the strength of the relationship between urban form and mobility behavior. Although several studies have identified a strong correlation between these variables, there is as yet scant evidence to support policy interventions that target land use as a means of influencing travel. To the contrary, some of the more recent research has cast skepticism on the proposition that the relationship is causative, recognizing the possibility that households endogenously self-select themselves into communities that support their preferences for particular transportation modes. Focusing on individual automobile travel, the present study seeks to contribute to this line of inquiry by estimating econometric models on a panel of travel-diary data collected in Germany between 1996 and 2003. Specifically, we employ the two-part model (2PM)—a procedure involving probit and OLS estimators—to assess the determinants of the discrete decision to use the car and the continuous decision of distance traveled. Beyond modeling variables that capture the urban form features that are commonly suggested to influence mobility behavior, including mixed use and public transit, this study employs instrumental variables to control for potential endogeneity emerging from the simultaneity of residential and mode choices. Unlike much of the work to date, our results suggest that urban form has a causative impact on car use, a finding that is robust to alternative econometric specifications.

What affects commute mode choice: neighborhood physical structure or preferences toward neighborhoods?

The academic literature on the impact of urban form on travel behavior has increasingly recognized that residential location choice and travel choices may be interconnected. We contribute to the understanding of this interrelation by studying to what extent commute mode choice differs by residential neighborhood and by neighborhood type dissonance—the mismatch between a commuter’s current neighborhood type and her preferences regarding physical attributes of the residential neighborhood. Using data from the San Francisco Bay Area, we find that neighborhood type dissonance is statistically significantly associated with commute mode choice: dissonant urban residents are more likely to commute by private vehicle than consonant urbanites but not quite as likely as true suburbanites. However, differences between neighborhoods tend to be larger than between consonant and dissonant residents within a neighborhood. Physical neighborhood structure thus appears to have an autonomous impact on commute mode choice. The analysis also shows that the impact of neighborhood type dissonance interacts with that of commuters’ beliefs about automobile use, suggesting that these are to be reckoned with when studying the joint choices of residential location and commute mode.