The road networks from sand mine to railway get used frequently by heavy trucks that are hauling sand from the mines to the railway loading stations to get shipped away. This project uses GIS to calculate the amount of roads in each county and the cost of the trucks using the roads. The data for the amount of trips the trucks are making is hypothetical and the figures are made up for the purpose of this lab. The goal of this lab is to get introduced to network analysis and its features on ArcMap.
Methods:
To begin this lab a python script was made to filter out the mines and railway terminals to get railways with loading stations that are not located at a mine and to get mines that actually extract sand and do not have a railway terminal located at the facility. This code can be found in the Python Scripts blog post.
In ArcMap the network analysis toolbar was used to complete steps in this lab. The first step was to make a layer in the network analyst tools. This was done by using the Make Closest Facility tool and called Closest Facility. The next step was to find the closest railway loading station to the mines. To do this the add locations tool was used to add the mines with no railway terminal at the facility and the railways terminals not at a mine. When setting up the add location tools the mines were set as the incidents and the railways were set as the terminals. Then the solve tool was used to create the best street routes from the mines to the railways. The next step was to make this routes layer a feature class. In the model builder, a model only tool of select data was used to select the routes. Then the copy features tool was used to make those selected features into a feature class. In order for the routes to be the appropriate units, the data from this point in the model had to be projected. The Project tool was used to project the routes into NAD 83 Wisconsin TM feet. This is important for later. The next step in the process was to find the amount of road that is used for sand transportation in each county and to calculate the amount of money it costs each county. This was done by using the intersect tool to find the routes in each county. Then the summary tool was used to create a table with each county and the amount of road used for transportation in feet. Next, the add field tool was used to add a cost field to that table. The calculate field tool was used to convert the routes distance in feet to miles and multiply each mile by 2.2 cents to get the amount of money each county was owed in road damage. That number was then multiplied by 100 for a theoretical 50 truck trips to the railway and 50 back to the mine. The results from this equation were the cost in dollars for each county. The following image is the model showing all the tools and the results from the tools.
The following image shows the equation used to calculate the cost of transportation for each railway.
Results:
The routes in the map above are the best routes from the mines to the railway terminals. The table above shows how much road, in feet, is in each county and the corresponding cost of transportation in each county for the trucks moving sand from the mines to the railway and back to the mines. This cost is from the county to the mine company for wear and tear on the roads. Over a long period of time this cost can add up. For a theoretical 50 trips per year the cost is very manageable. If a mine has to make 50 trips a day the cost would go up significantly. Now that the model is made if a mine company wanted to know how much it would cost them for X amount of trips a year a simple modification of the cost equation could output the cost for each county the mine company has to drive through.
Conclusion:
This lab was a great way to get experience using the network analyst features of ArcMap and to get a little more experience using the model builder in ArcMap. The model builder allowed for the whole process to be laid out and ran more then once if changes needed to be made. It allowed for the network analyst tools to be utilized to make routes in a quick easy fashion and for costs to be calculated with those routes pain free. The network analyst features in ArcMap are can be very important for future projects and is a great set of tools to be familiar with.
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