Abstract
The planning phase in highway development is a very critical phase as it affects the latter phases of the project. During the preliminary planning phase in highway development, a location study is done. This is to try to set alignment alternatives that are cost efficient as far as land and construction costs. This thesis utilizes Geographic Information Systems (GIS) software in order to locate an optimal alignment for a new road connecting two points. Three criteria are taken into consideration; land cost, land slope and environmental features. A methodology is developed for optimizing a roadway alignment based on the three criteria, and is implemented in ArcView 8.1, the most updated GIS software package released by the Environmental Systems Research Institute (ESRI). The base of the process is to convert the study area into a grid or raster, which represents the search space for an optimal location, the Spatial Analyst extension in this software plays a major role. The methodology is applied on two case studies for new alignments in Duval County in the State of Florida. For each case, two optimal alignments are found, one is based on one factor which is the land cost, and another one which combines the land cost and land slope. In both cases the environmental features such as lakes and wetlands are accounted for. For each case study a smooth trial alignment is developed using the indications given by the outputs to overcome their jaggedness. The outputs are then compared to the proposed Florida Department of Transportation alignments. The comparison is based on right-of-way costs for the alignments. For both case studies, the right-of-way costs are found to be significantly lower for the two output optimal alignments, and the smooth trial alignment.
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