SOUTH UTAH COUNTY EXPRESSWAY
Design - Alexander Barton
I created a model in ArcGIS to calculate costs associated with wetlands, existing roads, parcels, slope, and distance.
Roads
Wetlands
Wetlands are expensive to build through and serve as an important habitat for many migratory birds. Thus, these features have both fiscal and environmental costs. These costs were modeled in ArcGIS, a geographic information system, and Figure 1 represents wetland areas in dark blue.
Data source: National Wetlands Inventory (NWI), U.S. Fish and Wildlife Service.
Figure 1. Wetlands modeled in dark blue.
Existing roads can be desirable in some instances and prohibitive in others for building. Costs associated with building roads were classified in Figure 2, with red representing infeasible routes (through residential neighborhoods or town centers, for example) and green representing the most feasible routes (down the I-15 corridor and U.S. Hwy 6, for example). Lime green, yellow, and orange roads fall somewhere in between.
Data source: Automated Geographic Reference Center (AGRC), State of Utah.
Figure 2. Roads are classified according to cost on a red (prohibitive) to green (desirable) scale.
Parcels
Property values range widely, and there are certain facilities decision-makers will want to preserve regardless of their cost (schools, churches, and museums, for example). Property costs were classified according to tax information where that was available. Estimated property costs were calculated for hundreds of additional properties. Parcels in pink have the lowest values, and properties increase in value according to gradient with dark red properties being the most expensive.
Data source: GIS Department, Utah County.
Figure 3. Properties range in value from least expensive (pink) to most expensive (dark red) .
Slope
Steep slopes are more expensive to build on that gentle slopes, and some slopes on the eastern bench are unsuitable for building. Slope aspect was classified according to a graduated scale (0-10), with green representing the gentlest slopes, yellow indicating areas of moderate slope, and red representing the steepest slopes. Later, slopes determined unsuitable for building were classified as "NODATA", meaning these pixels appear empty in subsequent maps.
Data source: U.S. Geological Survey
Figure 4. Slope is classified on a graduated scale with green areas representing gentle slope and red areas indicating steep slope.
Distance
Figure 5. The source area (through which the expressway must pass) is shown in orange, destinations in pink.
The new expressway route will coalesce to the extent possible five destination points throughout southern Utah County: Santaquin, Benjamin, Springville, Mapleton, and Spanish Fork Canyon (destinations are displayed in pink in Figure 5). All other costs being equal, the model will select the shortest route between the source area and the destinations so as to minimize costs.