11.522: UIS Research Seminar (Fall 2007) - Discussion notes
One of the most intriguing problems within urban land use and transportation research is the connection between the job and housing location and its impacts on commuting behavior. During the past four decades, a great deal of research has been conducted investigating hypotheses like spatial mismatch (Kein, 1968) and excess commuting (Hamilton, 1982). As a response to these hypotheses, the concept of job-housing balance was coming up as an approach to reduce the journey-to-work and soon received extensive attentions. In recent research, the measure of job accessibility was widely used to explain the interaction between land use and commuting and to evaluate the effects of job-housing balance policy.
Even though accessibility has long been used as an important goal in the land use and transportation planning and policymaking contexts, it was usually hard and ambiguous to find a technique to measure it. Traditionally, the empirical analytical models like the gravity model and utility model was used to approximate the accessibility of the places. However, these traditional models has limitations on analyzing spatial relationship of objectivities and activities like calculation of the distance, analysis of the catchments area and finding the shortest path. The advances in GIS and the availability of large amounts of data make it possible to overcome these difficulties (Stan, 1995). Also with the capabilities offered by GIS, the researchers are able to visualize the accessibility result, which facilitates the understanding and interpreting of problems. The GIS-based accessibility framework usually includes an external model beyond the GIS package. Such external models are mostly gravity or utility models, which are used to calculate accessibility indices. Pre and post processing were needed to integrate the external model with GIS package.
This session will discuss existing accessibility measurement methods and their applications for job accessibility and job housing balance evaluation. Two case studies will be covered based on the first two readings. The first case study examines the spatial and temporal disparities in job accessibility between those commuting by car and by public transit in the metropolitan areas of Boston and San Francisco. The second case study compares the results of job accessibility models and related job/housing balance measures with trends and spatial patterns in observed commuting times, trying to identify the drawbacks of the existing job/housing balance measures as indicators of commuting patterns.
Discussion Questions:
1. Based on two cases, discuss how do the locations of job and housing affect the commuting behaviors? Consider how would the use of Information and Communication Technology (ICT) like telecommunication and participative web affect the accessibility of the places and the commuting behaviors of people?
2. Researchers propose that the measures of accessibility should incorporate both the elements of transportation and activity (Burns 1979; Koenig 1980). For the case of job accessibility model, what are the other factors that should be considered in addition to the travel time, cost and the proximity of jobs and residents?
3. As data sharing becomes increasingly popular today, many research results were published to the public through web services. One good example is the Mapping Metro Boston Growth (http://uis.mit.edu/ctpp). Particularly for job accessibility’s case, what kind of influences can these services bring to planners and commuters?
4. It is already well recognized today that the accessibility involves both spatial and temporal elements. But most relevant research still stays on the spatial representation of accessibility. How can we incorporate the temporal character of accessibility to explain the interaction of transportation and land use?
Recommended Readings
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