# Determine Optimum Travel Cost Network

## Summary

Calculates the optimum cost network from a set of input regions.

## Usage

• One example application of this tool is finding the best network for emergency vehicles.

• The input regions can be either image services or feature services.

• In a raster, a region is a group of cells with the same value that are contiguous to one another (adjacent). When your input regions are identified by a raster, if any zones (cells with the same value) are composed of multiple regions, first preprocess the data to assign unique values to each region.

• Cell locations with NoData in the Input cost raster act as barriers.

• The Input cost raster cannot contain values of zero since the algorithm is a multiplicative process. If your cost raster does contain values of zero, and these values represent areas of lowest cost, change values of zero to a small positive value (such as 0.01) before running Determine Optimum Travel Cost Network

• For Ouput neighbor network, the neighbors are not identified by Euclidean distance but instead are identified by cost distance. Therefore, a region's closest neighbor is the cheapest one to travel to, not the one that is closest in distance

## Syntax

`DetermineOptimumTravelCostNetwork_ra (inputRegionsRasterOrFeatures, inputCostRaster, outputOptimumNetworkName, {outputNeighborNetworkName})`
 Parameter Explanation Data Type inputRegionsRasterOrFeatures The input regions that are to be connected by the least-cost network.Regions can be defined by either an image service or a feature service.If the region input is a raster, the regions are defined by groups of contiguous (adjacent) cells of the same value. Each region must be uniquely numbered. The cells that are not part of any region must be NoData. The raster type must be integer, and the values can be either positive or negative.If the region input is a feature, it can be polygons, lines, or points. Polygon feature regions cannot be composed of multipart polygons. Raster Layer; Image Service; Feature Layer; String inputCostRaster A raster defining the impedance or cost to move planimetrically through each cell.The value at each cell location represents the cost-per-unit distance for moving through the cell. Each cell location value is multiplied by the cell resolution while also compensating for diagonal movement to obtain the total cost of passing through the cell.The values of the cost raster can be integer or floating point, but they cannot be negative or zero (you cannot have a negative or zero cost). Raster Layer; Image Service; String outputOptimumNetworkName The name of the output optimum network feature service.The polyline feature service of the optimum (least-cost) network of paths necessary to connect each of the input regions.Each path (or line) is uniquely numbered, and additional fields in the attribute table store specific information about the path. Those fields include the following:PATHID—Unique identifier for the pathPATHCOST—Total accumulative cost for the pathREGION1—The first region the path connectsREGION2—The other region the path connectsThis information provides you insight into the paths within the network.Since each path is represented by a unique line, there will be multiple lines in locations where paths travel the same route. String outputNeighborNetworkName(Optional) The name of the output Neighbor network feature service.The polyline feature service identifying all paths from each region to each of its closest-cost neighbors.Each path (or line) is uniquely numbered, and additional fields in the attribute table store specific information about the path. Those fields include the following:PATHID—Unique identifier for the pathPATHCOST—Total accumulative cost for the pathREGION1—The first region the path connectsREGION2—The other region the path connectsThis information provides you insight into the paths within the network and is particularly useful when deciding which paths should be removed if necessary.Since each path is represented by a unique line, there will be multiple lines in locations where paths travel the same route. String

## Code sample

DetermineOptimumTravelCostNetwork example 1 (Python window)

This example calculates the optimum travel cost network.

``````import arcpy

arcpy.DetermineOptimumTravelCostNetwork_ra(
"https://myserver/rest/services/sources/ImageServer",
"https://myserver/rest/services/costsurface/ImageServer",
"outoptimumnetwork1")``````
DetermineOptimumTravelCostNetwork example 2 (stand-alone script)

This example calculates the optimum travel cost network.

``````#-------------------------------------------------------------------------------
# Name: DetermineOptimumTravelCostNetwork_Ex_02.py
# Description: Calculates the optimum travel cost network.
# Requirements: ArcGIS Image Server

# Import system modules
import arcpy

# Set local variables
inputSourceLayer = 'https://MyPortal.esri.com/server/rest/services/Hosted/sources/ImageServer'
inputCostLayer = 'https://MyPortal.esri.com/server/rest/services/Hosted/costraster/ImageServer'
outputOptimumNetworkName = 'outNetworkRaster'
outputNeighborName = 'outNeighborRaster'

arcpy.DetermineOptimumTravelCostNetwork_ra(inputSourceLayer, zoneField, inputCostLayer,
outputOptimumNetworkName, outputNeighborName)``````

## Licensing information

• ArcGIS Desktop Basic: Requires ArcGIS Image Server
• ArcGIS Desktop Standard: Requires ArcGIS Image Server
• ArcGIS Desktop Advanced: Requires ArcGIS Image Server