Does Dissonance Between Desired and Current Residential Neighborhood Type Affect Individual Travel Behaviour?
T Schwanen, Utrecht University, NL; P Mokhtarian, University of California Davis, US
In the USA and Europe land use based solutions to transportation problems have rapidly gained in popularity over the past decade. Among academic researchers and practitioners the principles of New Urbanism (in the USA) or the Compact City (Europe) seem to have become the dominant mode of thinking. This popularity is not in the least the result of numerous empirical studies demonstrating that living in higher-density, mixed-use neighborhoods is associated with less car use compared to living in low-density, suburban environments (e.g. Frank and Pivo, 1994; Kockelman, 1997). As theoretical frameworks and research designs have become more sophisticated, however, researchers are more cautious regarding the influence of the built environment on travel behavior. Now that sociodemographic characteristics, such as gender and income, are incorporated in most research, a finding that has been replicated frequently is that such personal and household related factors are more important than the built environment (Kitamura et al., 1997; Schwanen et al., 2003; Stead, 2001). In addition, it has been become clear that the built environment is not equally relevant to all dimensions of travel/activity behavior. For instance, Schwanen (2003) shows that built environment characteristics are less relevant to people?s time use and the organization of daily activity patterns than to the traditionally more heavily researched dimensions of travel behavior like distance traveled, mode choice, and trip frequencies.
Nonetheless, even in studies of these more conventional measures of travel behavior has the role of the built environment been downplayed. Using micro-economic demand functions, Randall Crane and colleagues have questioned the arguments that neighborhood street patterns or land use characteristics have a significant impact on car or pedestrian travel (Boarnet and Sarmiento, 1998; Crane, 1996; Crane and Crepeau, 1998). Further, recent work by Cervero (2002) and Rajamani et al. (2003) has criticized previous studies regarding the built environment and mode choice for omitting level-of-service (LOS) variables that measure the generalized costs of competing modes. If these LOS factors are taken into account, the contribution of built environment mobility and advances in transport technology have encouraged residential, retail and employment functions to decentralise. Land use trends and travel patterns have reinforced each other in the emergence of a more dispersed, highly mobile and car dependent society, reflected in the relative decline of populations in large urban centres and a corresponding population growth in small towns and villages. Such a process poses fundamental questions in the wider debate over sustainable development and lifestyles. There is therefore a need to be able to quantify sustainability with particular reference to lifestyles and travel patterns. The quantification requires a robust and policy relevant mechanism for its measurement and this paper attempts to profile a strategy that satisfies both of these requirements.
Sustainability, which has gained a high profile on countless governmental agendas, is one of the many abused terms in modern environmental science - meaning different things to different people. Expert opinion and public perception present two faces of the present quest for sustainability. Only by examining such facets, can sustainability generate an appropriate framework for policy application.
Within the context of transport policy, we discuss the interpretation of travel behaviour sustainability by both experts and the general public. Two major relevant policy behavioural strands are emphasised:
1. location and access to facilities and their importance for sustainability of contemporary lifestyles, and
2. length of residency and the potential role of habit as it influences sustainability, i.e. can new residents in brownfield sites be persuaded to behave in a manner consistent with established residents with their greater tendency to use public transport.
The model of integration, based on multi-attribute utility theory, links the experts and the households through:
i) an analytic hierarchy of travel behaviour indicators designed to assess expert opinion and ii) a corresponding points-scheme designed to assess individual households.
The paper will describe the methodology of the process and outline the findings relevant to current transport policy based on
* mode of transport used by a household in activity behaviour
* location of activities utilised by a household
* frequency of activity trips made by a household
* proximity of public transport to a household and
* number of private motor vehicles and licences available to a household.
A linear aggregation of the expert weightings and the household scores provides a discriminating measure for the travel behaviour sustainability of each sampled household. The measure is referred to as the household sustainability index, (HSI).
The research was carried out over 1000 households distributed across four settlement classes situated along a key commuter corridor of the Belfast City Region (radius of 50km). The settlement classes ranged from inner-city brownfield/infill sites through an edge of city settlement, an outer city settlement through to a typical suburbanised village situated at the southern edge of the green belt surrounding the Belfast Urban Area. This transect facilitates the testing of the following hypothesis: suburbanisation is militating (know-how, capital) and the will to overcome barriers, including those that can exist between different territorial units.
The paper will present the methodology and the results of the comparison analyses of the socio-economic effects of the different type of investments for different modes. Most of the effects can be presented in a quantitative way. The influence of the effectiveness of the supporting policy as well as the institutional and organisational framework will be assessed. The results of the project will illuminate full variety of effects of urban transport infrastructure investments, including the external effects. This will help decision makers to get better knowledge about the interrelation of infrastructure and related development within urban agglomerations.
Association for European Transport