Visualizing Road Network Congestion to Inform Regional Planning in Southern Maine

This work presents a model by which road network congestion (traffic congestion) may be analyzed at spatial units other than the road segments themselves. Using Geographic Information Systems (GIS), I present a method for apportioning road segments and aggregating the characteristics of the segments – namely, an index of the potential for congestion to occur at various times of day – to any polygon containing them. The present work uses U.S. Census Block Groups as the unit of analysis; however, any areal unit can be used, including traffic analysis zones (TAZs), zoning zones, or even entire municipalities. The method of aggregating characteristics to larger areal units allows for easier analysis in combination with other data sources. To increase the usefulness of the method, aggregation is completed using several different methods. In this analysis, road traffic volumes and capacity estimates are used in conjunction with population data and population change forecasts to visualize the potential for congestion at present, and to project the potential for congestion in 2030. The areas most and least at risk of congestio