Thor Dodson

The US Interstate Highway System had a significant impact on market accessibility and transportation costs between regions. Whether this should lead to increased clustering of economic activity due to increased ‘economic centripetal forces’ or a dispersal from ‘centrifugal forces’ depends on factors that differ by industry. This paper suggests the impact depends on truck transportation utilization and input-output linkages. Utilizing travel time data constructed using GIS techniques along with BEA data on the spatial inequality of economic activity, a panel estimation is conducted to test the theory and regional variation is utilized to support the finding.

spatial distribution index

travel time matrix construction

This paper examines the relevant literatures regarding roads and the economy. This is an early draft which will cover: early economic thinkers on the subject such as Cantillon, Condillac and Steuart, Adam Smith, von Thunan, Marshall, Weber, Hotelling, Losch, Alonso, Hoover, Ohlin, Sathail, Moore and Tesch; the cost-benefit approach and how roads are valued; the production function approach; empirical strategies; modern urban economics including Fujita and Baum-Snow; the new economic geography including Krugman, Fujita, Venables, Redding and Turner; the market access literature including gravity trade models and modern GIS data implementation; as well as the representation of roads using graph theory.

Literature Tree

A spatial monopolistic competition model is constructed in the spirit of the new economic geography. Firms of different type compete over a 2-D space where transport is costly for the business of households and other firms as intermediate goods. Firms enter and exit based on profitability. A road system alters the space of transport costs and the patterns of regional activity.

model simulation

This article discusses the inequities in exposure to highway noise, which can have adverse effects on health, productivity, and quality of life. If certain subpopulations tend to live near highways because of structural inequality, gentrification, lack of social capital, or other reasons, then highway noise can contribute to inequity in a systematic way. The authors developed an online mapping application, the Noise Inequity Identification Tool (NIIT), to visualize the noise damage cost of noise pollution from road segments, the noise-equity ratios at the county level, and the population distribution of various demographics. The methodology combines estimates of roadway traffic noise levels with the cost of noise damage from the hedonic pricing literature and estimates of the number of households affected to estimate the noise damage cost for each road segment in the U.S. The cost of the noise damage accruing to each demographic is then aggregated over a larger region and normalized by their proportion of the population to calculate the “noise-equity ratio,” revealing substantial inequities in highway noise exposure between demographics at a variety of spatial scales. By using this tool, planners and practitioners can easily identify regions with existing highway noise exposure inequities and pinpoint roadways with excessive noise damage costs to recommend potential externality mitigation projects.

GitHub