| Popis: |
Suburbanization that has occurred across the U.S. since the middle of last century (Garreau 1991). With this continued growth come sustainability concerns associated with low density development. The concern that receives the most media attention is the increase in greenhouse gases associated with increased automobile use. However there are other concerns about the impact of these development patterns on environmental, social, and economic sustainability. Examples of these concerns include access to goods and services, the distribution of employment opportunities, how public transit might better serve residents. Transportation, particularly private auto use, matters immensely in each of the aforementioned aspects of sustainability, whether research is focused on getting particular people out of cars to curb greenhouse gas emissions, facilitating access to more job opportunities for low-income people, or measuring all of the economic activity related to either. In measuring the sustainability of an area, the journey to work reveals important insights about typical transportation patterns of residents. For example, how much farther minority residents are forced to travel to work (Kain 1968), the effectiveness of diversity and design on public transit use (Cervero and Kockelman 1997), and whether people self select into neighborhoods where they do not have to drive (Schwanen and Mokhtarian 2005). Journey to work data and the excess commuting framework have been used to quantify the effects of land-use on commuting patterns in cities and metro regions for over 30 years (Kanaroglou, Higgins and Chowdhury 2015, Ma and Banister 2006). Much research has gone into improving the applicability of the framework by making it more representative of reality. Insights from studies using this framework can inform planners and policy makers by quantitatively assessing the layout of cities across time and/or space. These studies serve to illustrate some of the more unsustainable aspects of cities by quantifying how much travel is built into an urban region. However, there exists an important need to update these works periodically as new data and analytical tools are made available so that policies aimed at improving an area’s sustainability can be assessed. Even the delineation of a metropolitan region is not static and there is a need to better determine how these areas are defined and how the definitions affect journey to work analyses. Finally, there is an ongoing debate about whether regions are sprawling or polycentric in terms of their urban forms and whether or not these different forms lead to shorter commuting outcomes for residents. The chapters in this dissertation look at these three needs specifically in order to better measure and contextualize how urban form influences travel and how it is analyzed. This research serves, in part, to extend previous work in novel ways by analyzing urban forms from several different perspectives, including over-time and across space, how choose what to analyze when investigating urban form, and finally, how the excess commuting framework might further clarify how we explicitly define urban form in terms of centricity. |
