Summary
Provides access to analysis properties from a route network analysis layer. The GetSolverProperties function is used to obtain a RouteSolverProperties object from a route network analysis layer.
Discussion
The RouteSolverProperties object provides read and write access to all the analysis properties of a route network analysis layer. The object can be used to modify the desired analysis properties of the route layer, and the corresponding layer can be resolved to determine the appropriate results. A new route layer can be created using the Make Route Analysis Layer geoprocessing tool. Obtaining the RouteSolverProperties object from a new route layer allows you to reuse the existing layer for subsequent analyses rather than create a layer for each analysis, which can be slow.
After modifying the properties of the RouteSolverProperties object, the corresponding layer can be immediately used with other functions and geoprocessing tools. There is no refresh or update of the layer required to honor the changes modified through the object.
Properties
| Property | Explanation | Data Type |
| accumulators (Read and Write) | Provides the ability to get or set a list of network cost attributes that are accumulated as part of the analysis. An empty list, [], indicates that no cost attributes are accumulated. | String |
| attributeParameters (Read and Write) | Provides the ability to get or set the parameterized attributes to be used in the analysis. The property returns a Python dictionary. The dictionary key is a two-value tuple consisting of the attribute name and the parameter name. The value for each item in the dictionary is the parameter value. Parameterized network attributes are used to model some dynamic aspect of an attribute's value. For example, a tunnel with a height restriction of 12 feet can be modeled using a parameter. In this case, the vehicle's height in feet should be specified as the parameter value. If the vehicle is taller than 12 feet, this restriction will then evaluate to True, thereby restricting travel through the tunnel. Similarly, a bridge could have a parameter to specify a weight restriction. Attempting to modify the attributeParameters property in place won't result in updated values. Instead, you should always use a new dictionary object to set values for the property. The following two code blocks demonstrate the difference between these two approaches. Do not attempt to modify the attributeParameters property in place; this coding method will not work. Modify the attributeParameters property using a new dictionary object. | Dictionary |
| findBestSequence (Read and Write) | Controls whether the stops are reordered to find optimal routes. The following is a list of possible values:
| String |
| ignoreInvalidLocations (Read and Write) | Specifies whether invalid input locations will be ignored. Typically, locations are invalid if they cannot be located on the network. When invalid locations are ignored, the solver will skip them and attempt to perform the analysis using the remaining locations.
| String |
| impedance (Read and Write) | Provides the ability to get or set the network cost attribute used as impedance. This cost attribute is minimized while determining the best route. | String |
| orderingType (Read and Write) | Controls the ordering of stops when findBestSequence property is set to FIND_BEST_ORDER. The following is a list of possible values:
| String |
| outputPathShape (Read and Write) | Provides the ability to get or set the shape type for the route features that are output by the solver. The following is a list of possible values:
| String |
| restrictions (Read and Write) | Provides the ability to get or set a list of restriction attributes that are applied for the analysis. An empty list, [], indicates that no restriction attributes are used for the analysis. | String |
| solverName (Read Only) | Returns the name of the solver being referenced by the network analysis layer used to obtain the solver properties object. The property always returns the string value Route Solver when accessed from a RouteSolverProperties object. | String |
| streetDirectionsProperties (Read and Write) | Provides read and write access to StreetDirectionsProperties, allowing you to customize the directions output from your route layer. | Object |
| timeOfDay (Read and Write) | Provides the ability to get or set the start date and time for the route. Route start time is mostly used to find routes based on the impedance attribute that varies with the time of the day. For example, a start time of 9 a.m. could be used to find a route that considers the rush-hour traffic. A value of None can be used to specify that no date and time should be used. Instead of using a particular date, a day of the week can be specified using the following dates:
For example, to specify that the route should start at 5:00 p.m. on Tuesday, specify the value as datetime.datetime(1900, 1, 2, 17,0,0). The timeZoneUsage parameter specifies whether the date and time refer to UTC or the time zone in which the first stop is located. | DateTime |
| timeZoneUsage (Read and Write) | Specifies the time zone of the timeOfDay parameter.
When solving a route analysis that spans across multiple time zones and setting a start time, the orderingType cannot be set to PRESERVE_NONE. A starting location and time zone must be fixed. | String |
| timeZoneUsageForTimeFields (Read and Write) |
Specifies the time zone of datetime fields in the input data, such as the fields used for time windows.
| String |
| travelMode (Read Only) | Accesses the travel mode set on a network analysis layer as an arcpy.na.TravelMode object. | Object |
| uTurns (Read and Write) | Provides the ability to get or set the policy that indicates how the U-turns at junctions that could occur during network traversal between stops are being managed by the solver. The following is a list of possible values:
| String |
| useHierarchy (Read and Write) | Controls the use of the hierarchy attribute while performing the analysis. The following is a list of possible values:
| String |
| useTimeWindows (Read and Write) | Controls if time windows will be used at the stops. The following is a list of possible values:
Note:This property has been maintained for backward compatibility, but it is ignored in ArcGIS Pro. Route layers in ArcGIS Pro will always use time windows if the time windows are populated | String |
Method Overview
| Method | Explanation |
| applyTravelMode (travel_mode) | Updates the analysis properties of a network analyst layer based on a travel mode object. The updated network analyst layer can then be solved to complete the analysis. |
Methods
applyTravelMode (travel_mode)
| Parameter | Explanation | Data Type |
travel_mode | A variable that references a travel mode object derived from a network dataset. A list of travel mode objects can be obtained by calling the arcpy.na.GetTravelModes function. | Object |
When a network analyst layer is created, it is assigned default values for all of its analysis properties. The individual analysis properties can be updated using a solver properties object obtained from the network analyst layer. A travel mode stores a predefined set of analysis settings that help to perform a particular analysis, such as a walking time travel mode that stores the analysis settings required to perform a time-based walking analysis.
Using the applyTravelMode method, all the analysis settings that are defined in a travel mode can be applied at once. After the analysis properties are updated, the network analyst layer can be solved to complete the analysis.
If there is an error when updating the solver properties, such as when the provided travel mode references properties that don't exist on the current network dataset or references properties that are no longer applicable to the network dataset that was used to create the network analyst layer corresponding to the solver properties object, no exceptions are raised. The method will execute successfully, but you will get errors when you try to solve such a network analyst layer.
If the travel_mode parameter does not reference a travel mode object or a string, a TypeError exception is raised. If the travel_mode parameter references a string and the string cannot be internally converted to a valid string representation of a travel mode object, a ValueError exception is raised.
Code sample
The script shows how to find the fastest route between a set of stops at two times of day. The travel time is different because of changing traffic conditions. The script illustrates how to create only one instance of a route layer and modify the timeOfDay property using the RouteSolverProperties object to achieve the desired results.
Legacy:
The GetNASublayer function can be used to retrieve the sublayers of a network analysis layer. It was introduced in ArcGIS Pro 2.7. In prior software versions, the best way to retrieve a sublayer object of a network analysis layer was to use the listLayers method of the network analysis Layer object using the sublayer name as a wildcard.
# Name: RouteSolverProperties_workflow_01.py
# Description: Find the fastest route at two different times of day. The travel
# time is different because of traffic conditions. Use the
# RouteSolverProperties object to update an existing Route layer
# before re-running the analysis.
# Requirements: Network Analyst Extension
# Import system modules
import arcpy
from arcpy import env
import os
try:
# Check out Network Analyst license if available. Fail if the Network Analyst license is not available.
if arcpy.CheckExtension("network") == "Available":
arcpy.CheckOutExtension("network")
else:
raise arcpy.ExecuteError("Network Analyst Extension license is not available.")
# Set environment settings
output_dir = "C:/Data"
# The NA layer's data will be saved to the workspace specified here
env.workspace = os.path.join(output_dir, "Output.gdb")
env.overwriteOutput = True
# Set local variables
input_gdb = "C:/Data/SanFrancisco.gdb"
network = os.path.join(input_gdb, "Transportation", "Streets_ND")
stops = os.path.join(input_gdb, "Analysis", "Stores")
route_0830 = os.path.join(output_dir, "Output.gdb", "Route_MorningRush")
route_1100 = os.path.join(output_dir, "Output.gdb", "Route_MidMorning")
# Make a new route layer using travel time as impedance to determine fastest
# route
route_layer = arcpy.na.MakeRouteAnalysisLayer(network, "StoresRoute",
"Driving Time",
time_of_day="8:30 AM").getOutput(0)
# Get the network analysis class names from the route layer
na_classes = arcpy.na.GetNAClassNames(route_layer)
# Load stops
arcpy.na.AddLocations(route_layer, na_classes["Stops"], stops)
# Solve the route layer
arcpy.na.Solve(route_layer)
# Get the routes sublayer from the route layer
routes_sublayer = arcpy.na.GetNASublayer(route_layer, "Routes")
# Save the resulting route as a feature class. This route was solved at 8:30
# AM, morning rush hour.
arcpy.management.CopyFeatures(routes_sublayer, route_0830)
# Get the RouteSolverProperties object from the route layer to modify the
# timeOfDay property of the route layer.
solver_props = arcpy.na.GetSolverProperties(route_layer)
# Set the impedance property to "Meters" to determine the shortest route.
solver_props.timeOfDay = "11:00 AM"
# Re-solve the route layer
arcpy.na.Solve(route_layer)
# Save the resulting route as a feature class. This route was solved at 11:00
# AM, mid-morning when traffic is probably lighter.
arcpy.management.CopyFeatures(routes_sublayer, route_1100)
print("Script completed successfully")
except Exception as e:
# If an error occurred, print line number and error message
import traceback, sys
tb = sys.exc_info()[2]
print("An error occured on line %i" % tb.tb_lineno)
print(str(e))This script shows how to apply the TruckingTime travel mode to an existing layer.
#Get the route layer object from a layer named "Route" in the map
doc = arcpy.mp.ArcGISProject('current')
map_obj = doc.listMaps()[0]
route_layer = map_obj.listLayers('Route')[0]
#Get the Trucking Time travel mode from the network dataset
desc = arcpy.Describe(route_layer)
travel_modes = arcpy.na.GetTravelModes(desc.network.catalogPath)
trucking_mode = travel_modes["Trucking Time"]
#Apply the travel mode to the analysis layer
solver_properties = arcpy.na.GetSolverProperties(route_layer)
solver_properties.applyTravelMode(trucking_mode)