GenerateServiceAreas (ServiceAreas)

Summary

This ArcGIS Online service determines network service areas around facilities. A network service area is a region that encompasses all streets that can be accessed within a given distance or travel time from one or more facilities. For instance, the 10-minute service area for a facility includes all the streets that can be reached within 10 minutes from that facility.

Service areas are commonly used to visualize and measure accessibility. For example, a three-minute drive-time polygon around a grocery store can determine which residents are able to reach the store within three minutes and are thus more likely to shop there.

Illustration

Multiple service area polygons

Usage

Syntax

GenerateServiceAreas_naagol (Facilities, Break_Values, Break_Units, {Analysis_Region}, Travel_Direction, Time_of_Day, Use_Hierarchy, UTurn_at_Junctions, Polygons_for_Multiple_Facilities, Polygon_Overlap_Type, {Detailed_Polygons}, Polygon_Trim_Distance, Polygon_Simplification_Tolerance, Point_Barriers, {Line_Barriers}, Polygon_Barriers, Restrictions, {Attribute_Parameter_Values}, {Time_Zone_for_Time_of_Day}, {Travel_Mode}, {Impedance}, {Service_Areas})
ParameterExplanationData Type
Facilities

The facilities around which service areas are generated. You can load up to 1,000 facilities.

The facilities feature set has an associated attribute table. The fields in the attribute table are listed below and described.

ObjectID: The system-managed ID field.

Name: The name of the facility. If the name is not specified, a name is automatically generated at solve time.

All fields from the input facilities are included in the output polygons when the Polygons for Multiple Facilities parameter is set to Overlapping or Not Overlapping. The ObjectID field on the input facilities is transferred to the FacilityOID field on the output polygons.

Feature Set
Break_Values

Specifies the size and number of service area polygons to generate for each facility. The units are determined by the Break Units value.

Multiple polygon breaks can be set to create concentric service areas per facility. For instance, to find 2-, 3-, and 5-mile service areas for each facility, type 2 3 5, separating the values with a space, and set Break Units to Miles. There is no limit to the number of break values you specify.

The size of the maximum break value can't exceed the equivalent of 300 minutes or 300 miles (482.80 kilometers). When generating detailed polygons, the maximum service-area size is limited to 15 minutes and 15 miles (24.14 kilometers).

String
Break_Units

The unit for the Break Values parameter.

The units you choose for this parameter determine whether the tool will create service areas by measuring driving distance or driving time. Choose a time unit to measure driving time. To measure driving distance, choose a distance unit. Your choice also determines in which units the tool will report total driving time or distance in the results. The choices are:

  • Meters
  • Kilometers
  • Feet
  • Yards
  • Miles
  • Nautical Miles
  • Seconds
  • Minutes
  • Hours
  • Days

String
Analysis_Region
(Optional)

Specify the region in which to perform the analysis. If a value is not specified for this parameter, the tool will automatically calculate the region name based on the location of the input points. Setting the name of the region is recommended to speed up the tool execution. To specify a region, use one of the following values:

  • Europe
  • Greece
  • India
  • Japan
  • Korea
  • MiddleEastAndAfrica
  • NorthAmerica
  • Oceania
  • SouthAmerica
  • SouthEastAsia
  • Taiwan
  • Thailand

String
Travel_Direction

Specifies whether the direction of travel used to generate the service area polygons is toward or away from the facilities.

  • Away From Facility—The service area is generated in the direction away from the facilities.
  • Towards Facility—The service area is created in the direction towards the facilities.

The direction of travel may change the shape of the polygons because impedances on opposite sides of streets may differ or one-way restrictions may exist, such as one-way streets. The direction you should choose depends on the nature of your service area analysis. The service area for a pizza delivery store, for example, should be created away from the facility, whereas the service area of a hospital should be created toward the facility.

String
Time_of_Day

The time to depart from or arrive at the facilities. The interpretation of this value depends on whether travel is toward or away from the facilities.

  • It represents the departure time if Travel Direction is set to Away from Facility.
  • It represents the arrival time if Travel Direction is set to Toward Facility.

You can use the Time Zone for Time of Day parameter to specify whether this time and date refers to UTC or the time zone in which the facility is located.

Repeatedly solving the same analysis, but using different Time of Day values, allows you to see how a facility's reach changes over time. For instance, the five-minute service area around a fire station may start out large in the early morning, diminish during the morning rush hour, grow in the late morning, and so on, throughout the day.

Date
Use_Hierarchy

Specify whether hierarchy should be used when finding the best route between the facility and the incident.

  • Checked (True)—Use the hierarchy attribute for the analysis. Using a hierarchy results in the solver preferring higher-order edges to lower-order edges. Hierarchical solves are faster, and they can be used to simulate the preference of a driver who chooses to travel on freeways over local roads when possible—even if that means a longer trip.
  • Unchecked (False)—Do not use the hierarchy attribute for the analysis. Not using a hierarchy yields an accurate service area measured along all edges of the network dataset regardless of hierarchy level.

Regardless of whether the Use Hierarchy parameter is checked (True), hierarchy is always used when the largest break value exceeds 240 minutes or 240 miles (386.24 kilometers).

Boolean
UTurn_at_Junctions

Use this parameter to restrict or permit the service area to make U-turns at junctions. In order to understand the parameter values, consider for a moment the following terminology: a junction is a point where a street segment ends and potentially connects to one or more other segments; a pseudo-junction is a point where exactly two streets connect to one another; an intersection is a point where three or more streets connect; and a dead-end is where one street segment ends without connecting to another. Given this information, the parameter can have the following values:

  • Allowed—U-turns are permitted everywhere. Allowing U-turns implies that the vehicle can turn around at any junction and double back on the same street. This is the default value.
  • Not Allowed—U-turns are prohibited at all junctions: pseudo-junctions, intersections, and dead-ends.
  • Allowed only at Dead Ends—U-turns are prohibited at all junctions, except those that have only one connected street feature (a dead end).
  • Allowed only at Intersections and Dead Ends—U-turns are prohibited at pseudo-junctions where exactly two adjacent streets meet, but U-turns are permitted at intersections and dead ends. This prevents turning around in the middle of the road where one length of road happened to be digitized as two street features.

String
Polygons_for_Multiple_Facilities

Choose how service area polygons are generated when multiple facilities are present in the analysis.

  • Overlapping—Creates individual polygons for each facility. The polygons can overlap each other. This is the default value.
  • Not Overlapping—Creates individual polygons such that a polygon from one facility cannot overlap polygons from other facilities; furthermore, any portion of the network can only be covered by the service area of the nearest facility.
  • Merge by Break Value—Creates and joins the polygons of different facilities that have the same break value.

When using Overlapping or Not Overlapping, all fields from the input facilities are included in the output polygons, with the exception that values from the input ObjectID field are transferred to the FacilityOID field of the output polygons. The FacilityOID field is null when merging by break value, and the input fields are not included in the output.

String
Polygon_Overlap_Type

Specifies the option to create concentric service area polygons as disks or rings. This option is applicable only when multiple break values are specified for the facilities.

  • Rings—The polygons representing larger breaks exclude the polygons of smaller breaks. This creates polygons going between consecutive breaks. Use this option if you want to find the area from one break to another. For instance, if you create 5- and 10-minute service areas, then the 10-minute service area polygon will exclude the area under the 5-minute service area polygon. This is the default value.
  • Disks—Creates polygons going from the facility to the break. For instance, if you create 5- and 10-minute service areas, then the 10-minute service area polygon will include the area under the 5-minute service area polygon.

String
Detailed_Polygons
(Optional)

Specifies the option to create detailed or generalized polygons.

  • Unchecked (False)—Creates generalized polygons, which are generated quickly and are fairly accurate. This is the default.
  • Checked (True)—Creates detailed polygons, which accurately model the service area lines and may contain islands of unreached areas. This option is much slower than generating generalized polygons. This option isn't supported when using hierarchy.

If your facilities are in an urban area with a grid-like street network, the difference between generalized and detailed service areas would be minimal. However, if your facilities are in a region containing mountain and rural roads, the detailed service areas may present significantly more accurate results than generalized service areas.

The tool supports generating detailed polygons only if the largest value specified in the Break Values parameter is less than or equal to 15 minutes or 15 miles (24.14 kilometers).

Boolean
Polygon_Trim_Distance

Specifies the distance within which the service area polygons are trimmed. This is useful when finding service areas in places that have a sparse street network and you don't want the service area to cover large areas where there are no street features.

The default value is 100 meters. No value or a value of 0 for this parameter specifies that the service area polygons should not be trimmed. This parameter value is ignored when using hierarchy.

Linear unit
Polygon_Simplification_Tolerance

Specify by how much you want to simplify the polygon geometry.

Simplification maintains critical vertices of a polygon to define its essential shape and removes other vertices. The simplification distance you specify is the maximum offset the simplified polygon boundaries can deviate from the original polygon boundaries. Simplifying a polygon reduces the number of vertices and tends to reduce drawing times.

Linear unit
Point_Barriers

Specify one or more points to act as temporary restrictions or represent additional time or distance that may be required to travel on the underlying streets. For example, a point barrier can be used to represent a fallen tree along a street or time delay spent at a railroad crossing.

The tool imposes a limit of 250 points that can be added as barriers.

When specifying the point barriers, you can set properties for each one, such as its name or barrier type, by using attributes. The point barriers can be specified with the following attributes:

Name: The name of the barrier.

BarrierType: Specifies whether the point barrier restricts travel completely or adds time or distance when it is crossed. The value for this attribute is specified as one of the following integers (use the numeric code, not the name in parentheses):

  • 0 (Restriction)—Prohibits travel through the barrier. The barrier is referred to as a restriction point barrier since it acts as a restriction.
  • 2 (Added Cost)—Traveling through the barrier increases the travel time or distance by the amount specified in the Additional_Time or Additional_Distance field. This barrier type is referred to as an added-cost point barrier.

Additional_Time: Indicates how much travel time is added when the barrier is traversed. This field is applicable only for added-cost barriers and only if the Break Units value is time based. This field value must be greater than or equal to zero, and its units are the same as those specified in the Break Units parameter.

Additional_Distance: Indicates how much distance is added when the barrier is traversed. This field is applicable only for added-cost barriers and only if the Break Units value is distance based. The field value must be greater than or equal to zero, and its units are the same as those specified in the Break Units parameter.

Feature Set
Line_Barriers
(Optional)

Specify one or more lines that prohibit travel anywhere the lines intersect the streets. For example, a parade or protest that blocks traffic across several street segments can be modeled with a line barrier. A line barrier can also quickly fence off several roads from being traversed, thereby channeling possible routes away from undesirable parts of the street network.

The tool imposes a limit on the number of streets you can restrict using the Line Barriers parameter. While there is no limit on the number of lines you can specify as line barriers, the combined number of streets intersected by all the lines cannot exceed 500.

When specifying the line barriers, you can set a name property for each one by using the following attribute:

Name: The name of the barrier.

Feature Set
Polygon_Barriers

Specify polygons that either completely restrict travel or proportionately scale the time or distance required to travel on the streets intersected by the polygons.

The service imposes a limit on the number of streets you can restrict using the Polygon Barriers parameter. While there is no limit on the number of polygons you can specify as the polygon barriers, the combined number of streets intersected by all the polygons should not exceed 2,000.

When specifying the polygon barriers, you can set properties for each one, such as its name or barrier type, by using attributes. The polygon barriers can be specified with the following attributes:

Name: The name of the barrier.

BarrierType: Specifies whether the barrier restricts travel completely or scales the time or distance for traveling through it. The field value is specified as one of the following integers (use the numeric code, not the name in parentheses):

  • 0 (Restriction)—Prohibits traveling through any part of the barrier. The barrier is referred to as a restriction polygon barrier since it prohibits traveling on streets intersected by the barrier. One use of this type of barrier is to model floods covering areas of the street that make traveling on those streets impossible.
  • 1 (Scaled Cost)—Scales the time or distance required to travel the underlying streets by a factor specified using the ScaledTimeFactor or ScaledDistanceFactor fields. If the streets are partially covered by the barrier, the travel time or distance is apportioned and then scaled. For example, a factor 0.25 would mean that travel on underlying streets is expected to be four times faster than normal. A factor of 3.0 would mean it is expected to take three times longer than normal to travel on underlying streets. This barrier type is referred to as a scaled-cost polygon barrier. It might be used to model storms that reduce travel speeds in specific regions.

ScaledTimeFactor: This is the factor by which the travel time of the streets intersected by the barrier is multiplied. This field is applicable only for scaled-cost barriers and only if the Break Units value is time based. The field value must be greater than zero and its units are the same as those specified in the Break Units parameter.

ScaledDistanceFactor: This is the factor by which the distance of the streets intersected by the barrier is multiplied. This attribute is applicable only for scaled-cost barriers and only if the Break Units value is distance based. The attribute value must be greater than zero.

Feature Set
Restrictions

Specify which travel restrictions should be honored by the tool when determining the service areas.

NoteNote:

The values you provide for this parameter are ignored unless Travel Mode is set to Custom.

A restriction represents a driving preference or requirement. In most cases, restrictions cause roads to be prohibited. For instance, using an Avoid Toll Roads restriction will result in a route that will include toll roads only when it is absolutely required to travel on toll roads in order to visit an incident or a facility. Height Restriction makes it possible to route around any clearances that are lower than the height of your vehicle. If you are carrying corrosive materials on your vehicle, using the Any Hazmat Prohibited restriction prevents hauling the materials along roads where it is marked as illegal to do so.

When generating detailed polygons, prohibited roads aren't covered by service area polygons may result in polygons with untraversable holes; however, when generating general or hierarchical service areas, restricted roads that are completely surrounded by traversable roads will be covered by the simplified service area polygon.

Below is a list of available restrictions and a short description.

NoteNote:

Some restrictions require an additional value to be specified for their desired use. This value needs to be associated with the restriction name and a specific parameter intended to work with the restriction. You can identify such restrictions if their names appear under the AttributeName column in the Attribute Parameter Values parameter. The ParameterValue field should be specified in the Attribute Parameter Values parameter for the restriction to be correctly used when finding traversable roads.

NoteNote:

Some restrictions are supported only in certain countries; their availability is stated by region in the list below. Of the restrictions that have limited availability within a region, you can check whether the restriction is available in a particular country by looking at the table in the Country List section of the Data coverage for network analysis services web page. If a country has a value of Yes in the Logistics Attribute column, the restriction with select availability in the region is supported in that country. If you specify restriction names that are not available in the country where your incidents are located, the service ignores the invalid restrictions. The service also ignores restrictions whose Restriction Usage parameter value is between 0 and 1 (see the Attribute Parameter Value parameter). It prohibits all restrictions whose Restriction Usage parameter value is greater than 0.

The tool supports the following restrictions:

  • Any Hazmat Prohibited—The results will not include roads where transporting any kind of hazardous material is prohibited.

    Availability: Select countries in North America and Europe

  • Avoid Carpool Roads—The results will avoid roads that are designated exclusively for carpool (high-occupancy) vehicles.

    Availability: All countries

  • Avoid Express Lanes—The results will avoid roads designated as express lanes.

    Availability: All countries

  • Avoid Ferries—The results will avoid ferries.

    Availability: All countries

  • Avoid Gates—The results will avoid roads where there are gates such as keyed access or guard-controlled entryways.

    Availability: All countries

  • Avoid Limited Access Roads—The results will avoid roads that are limited access highways.

    Availability: All countries

  • Avoid Private Roads—The results will avoid roads that are not publicly owned and maintained.

    Availability: All countries

  • Avoid Toll Roads—The results will avoid toll roads.

    Availability: All countries

  • Avoid Unpaved Roads—The results will avoid roads that are not paved (for example, dirt, gravel, and so on).

    Availability: All countries

  • Axle Count Restriction—The results will not include roads where trucks with the specified number of axles are prohibited. The number of axles can be specified using the Number of Axles restriction parameter.

    Availability: Select countries in North America and Europe

  • Driving a Bus—The results will not include roads where buses are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Driving a Delivery Vehicle—The results will not include roads where delivery vehicles are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Driving a Taxi—The results will not include roads where taxis are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Driving a Truck—The results will not include roads where trucks are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Driving an Automobile—The results will not include roads where automobiles are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Driving an Emergency Vehicle—The results will not include roads where emergency vehicles are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Height Restriction—The results will not include roads where the vehicle height exceeds the maximum allowed height for the road. The vehicle height can be specified using the Vehicle Height (meters) restriction parameter.

    Availability: Select countries in North America and Europe

  • Kingpin to Rear Axle Length Restriction—The results will not include roads where the vehicle length exceeds the maximum allowed kingpin to rear axle for all trucks on the road. The length between the vehicle kingpin and the rear axle can be specified using the Vehicle Kingpin to Rear Axle Length (meters) restriction parameter.

    Availability: Select countries in North America and Europe

  • Length Restriction—The results will not include roads where the vehicle length exceeds the maximum allowed length for the road. The vehicle length can be specified using the Vehicle Length (meters) restriction parameter.

    Availability: Select countries in North America and Europe

  • Riding a Motorcycle—The results will not include roads where motorcycles are prohibited. Using this restriction will also ensure that the results will honor one-way streets.

    Availability: All countries

  • Roads Under Construction Prohibited—The results will not include roads that are under construction.

    Availability: All countries

  • Semi or Tractor with One or More Trailers Prohibited—The results will not include roads where semis or tractors with one or more trailers are prohibited.

    Availability: Select countries in North America and Europe

  • Single Axle Vehicles Prohibited—The results will not include roads where vehicles with single axles are prohibited.

    Availability: Select countries in North America and Europe

  • Tandem Axle Vehicles Prohibited—The results will not include roads where vehicles with tandem axles are prohibited.

    Availability: Select countries in North America and Europe

  • Through Traffic Prohibited—The results will not include roads where through traffic (non local) is prohibited.

    Availability: All countries

  • Truck with Trailers Restriction—The results will not include roads where trucks with the specified number of trailers on the truck are prohibited. The number of trailers on the truck can be specified using the Number of Trailers on Truck restriction parameter.

    Availability: Select countries in North America and Europe

  • Use Preferred Hazmat Routes—The results will prefer roads that are designated for transporting any kind of hazardous materials.

    Availability: Select countries in North America and Europe

  • Use Preferred Truck Routes—The results will prefer roads that are designated as truck routes, such as the roads that are part of the national network as specified by the National Surface Transportation Assistance Act in the United States, or roads that are designated as truck routes by the state or province, or roads that are preferred by the trucks when driving in an area.

    Availability: Select countries in North America and Europe

  • Walking—The results will not include roads where pedestrians are prohibited.

    Availability: All countries

  • Weight Restriction—The results will not include roads where the vehicle weight exceeds the maximum allowed weight for the road. The vehicle weight can be specified using the Vehicle Weight (kilograms) restriction parameter.

    Availability: Select countries in North America and Europe

  • Weight per Axle Restriction—The results will not include roads where the vehicle weight per axle exceeds the maximum allowed weight per axle for the road. The vehicle weight per axle can be specified using the Vehicle Weight per Axle (kilograms) restriction parameter.

    Availability: Select countries in North America and Europe

  • Width Restriction—The results will not include roads where the vehicle width exceeds the maximum allowed width for the road. The vehicle width can be specified using the Vehicle Width (meters) restriction parameter.

    Availability: Select countries in North America and Europe

String
Attribute_Parameter_Values
(Optional)

Specify additional values required by some restrictions, such as the weight of a vehicle for Weight Restriction. You can also use the attribute parameter to specify whether any restriction prohibits, avoids, or prefers travel on roads that use the restriction. If the restriction is meant to avoid or prefer roads, you can further specify the degree to which they are avoided or preferred using this parameter. For example, you can choose to never use toll roads, avoid them as much as possible, or even highly prefer them.

NoteNote:

The values you provide for this parameter are ignored unless Travel Mode is set to Custom.

If you specify the Attribute Parameter Values parameter from a feature class, the field names on the feature class must match the fields as described below:

AttributeName: Lists the name of the restriction.

ParameterName: Lists the name of the parameter associated with the restriction. A restriction can have one or more ParameterName field values based on its intended use.

ParameterValue: The value for ParameterName used by the tool when evaluating the restriction.

Attribute Parameter Values is dependent on the Restrictions parameter. The ParameterValue field is applicable only if the restriction name is specified as the value for the Restrictions parameter.

In Attribute Parameter Values, each restriction (listed as AttributeName) has a ParameterName field value, Restriction Usage, that specifies whether the restriction prohibits, avoids, or prefers travel on the roads associated with the restriction and the degree to which the roads are avoided or preferred. The Restriction Usage ParameterName can be assigned any of the following string values or their equivalent numeric values listed within the parentheses:

  • PROHIBITED (-1)—Travel on the roads using the restriction is completely prohibited.
  • AVOID_HIGH (5)—It is highly unlikely for the tool to include in the route the roads that are associated with the restriction.
  • AVOID_MEDIUM (2)—It is unlikely for the tool to include in the route the roads that are associated with the restriction.
  • AVOID_LOW (1.3)—It is somewhat unlikely for the tool to include in the route the roads that are associated with the restriction.
  • PREFER_LOW (0.8)—It is somewhat likely for the tool to include in the route the roads that are associated with the restriction.
  • PREFER_MEDIUM (0.5)—It is likely for the tool to include in the route the roads that are associated with the restriction.
  • PREFER_HIGH (0.2)—It is highly likely for the tool to include in the route the roads that are associated with the restriction.

In most cases, you can use the default value, PROHIBITED, for the Restriction Usage if the restriction is dependent on a vehicle-characteristic such as vehicle height. However, in some cases, the value for Restriction Usage depends on your routing preferences. For example, the Avoid Toll Roads restriction has the default value of AVOID_MEDIUM for the Restriction Usage parameter. This means that when the restriction is used, the tool will try to route around toll roads when it can. AVOID_MEDIUM also indicates how important it is to avoid toll roads when finding the best route; it has a medium priority. Choosing AVOID_LOW would put lower importance on avoiding tolls; choosing AVOID_HIGH instead would give it a higher importance and thus make it more acceptable for the service to generate longer routes to avoid tolls. Choosing PROHIBITED would entirely disallow travel on toll roads, making it impossible for a route to travel on any portion of a toll road. Keep in mind that avoiding or prohibiting toll roads, and thus avoiding toll payments, is the objective for some; in contrast, others prefer to drive on toll roads because avoiding traffic is more valuable to them than the money spent on tolls. In the latter case, you would choose PREFER_LOW, PREFER_MEDIUM, or PREFER_HIGH as the value for Restriction Usage. The higher the preference, the farther the tool will go out of its way to travel on the roads associated with the restriction.

Record Set
Time_Zone_for_Time_of_Day
(Optional)

Specifies the time zone or zones of the Time of Day parameter.

  • Geographically Local:

    The Time of Day parameter refers to the time zone or zones in which the facilities are located. Therefore, the start or end times of the service areas are staggered by time zone.

    Setting Time of Day to 9:00 a.m., choosing geographically local for Time Zone for Time of Day, and solving causes service areas to be generated for 9:00 a.m. Eastern Time for any facilities in the Eastern Time Zone, 9:00 a.m. Central Time for facilities in the Central Time Zone, 9:00 a.m. Mountain Time for facilities in the Mountain Time Zone, and so on, for facilities in different time zones.

    If stores in a chain that span the U.S. open at 9:00 a.m. local time, this parameter value could be chosen to find market territories at opening time for all stores in one solve. First, the stores in the Eastern Time Zone open and a polygon is generated, then an hour later stores open in Central Time, and so on. Nine o'clock is always in local time but staggered in real time.

  • UTC:

    The Time of Day parameter refers to Coordinated Universal Time (UTC). Therefore, all facilities are reached or departed from simultaneously, regardless of the time zone each is in.

    Setting Time of Day to 2:00 p.m., choosing UTC, then solving causes service areas to be generated for 9:00 a.m. Eastern Standard Time for any facilities in the Eastern Time Zone, 8:00 a.m. Central Standard Time for facilities in the Central Time Zone, 7:00 a.m. Mountain Standard Time for facilities in the Mountain Time Zone, and so on, for facilities in different time zones.

    NoteNote:

    The scenario above assumes standard time. During daylight saving time, the Eastern, Central, and Mountain Times would each be one hour ahead (that is, 10:00, 9:00, and 8:00 a.m., respectively).

    One of the cases in which the UTC option is useful is to visualize emergency-response coverage for a jurisdiction that is split into two time zones. The emergency vehicles are loaded as facilities. Time of Day is set to now in UTC. (You need to determine what the current time and date are in terms of UTC to correctly use this option.) Other properties are set and the analysis is solved. Even though a time-zone boundary divides the vehicles, the results show areas that can be reached given current traffic conditions. This same process can be used for other times as well, not just for now.

Irrespective of the Time Zone for Time of Day setting, all facilities must be in the same time zone when Time of Day has a nonnull value and Polygons for Multiple Facilities is set to create merged or nonoverlapping polygons.

String
Travel_Mode
(Optional)

Choose the mode of transportation to model in the analysis.

  • Driving—Models traveling by car. It obeys one-way roads, avoids illegal turns, and follows other rules specific to cars. Dynamic travel speeds based on traffic are used where it is available.

  • Trucking—Models basic truck travel by prefering designated truck routes and using typical truck speeds. It also obeys one-way roads, avoids illegal turns, and so on. To model the characteristics of a specific truck, such as its height and weight, choose the Custom travel mode instead.

  • Walking—Follows paths and roads that allow pedestrian traffic.

  • Custom—This is the default value. Allows you to configure your own travel mode using the custom travel mode parameters (UTurn at Junctions, Use Hierarchy, Restrictions, Attribute Parameter Values, and Impedance). The default values of the custom travel mode parameters model traveling by car. You may want to choose Custom and set the custom travel mode parameters listed above to model a pedestrian with a fast walking speed or a truck with a given height, weight, and cargo of certain hazardous materials.

    By choosing Custom, the values you set for the custom travel mode parameters are included in the analysis. (Choosing another travel mode—Driving, Trucking, or Walking—causes any values you set for the custom travel mode parameters to be ignored; the tool overrides them with values that model a typical car, truck, or pedestrian.)

For modeling a custom truck mode, you would follow the steps listed below.

  1. Choose Custom for Travel Mode.
  2. Check (or set to True) Driving a Truck in the Restrictions parameter.
  3. Check all other restrictions that will help you model your truck.
  4. Set values for Attribute Parameter Values. This is where you can set the dimensions of your vehicle, including the height, weight, and length, and special values for restrictions you checked in the last step. You might also want to change whether those restrictions are prohibited (roads with the restriction are never traveled on), avoided (roads with the restriction are avoided as long as the detour to avoid them is not too far out of the way), or preferred (roads with the restriction are preferred as long as the detour to travel on them is not too far out of the way).
  5. Set UTurn at Junctions and Use Hierarchy.
  6. Set Impedance to Truck Time or Travel Distance.

For modeling a pedestrian with specific routing requirements, you would follow the same procedure as setting up a custom truck mode, but with the following differences:

  • Check (or set to True) the Walking restriction (and uncheck Driving a Truck).
  • Check other restrictions, such as Avoid Stairways. Uncheck others.
  • If necessary, set relevant attribute parameters, such as the the walking speed, in Attribute Parameter Values.
  • Set UTurn at Junctions to Allowed.
  • Uncheck (or set to False) Use Hierarchy.
  • Set Impedance to Walk Time or Travel Distance.

String
Impedance
(Optional)

Specify the impedance, which is a value that represents the effort or cost of traveling along road segments or on other parts of the transportation network.

Travel distance is an impedance; the length of a road in kilometers can be thought of as impedance. Travel distance in this sense is the same for all modes—a kilometer for a pedestrian is also a kilometer for a car. (What may change is the pathways on which the different modes are allowed to travel, which affects distance between points, and this is modeled by travel mode settings.)

Travel time can also be an impedance; a car may take one minute to travel a mile along an empty road. Travel times can vary by travel mode—a pedestrian may take more than 20 minutes to walk the same mile, so it is important to choose the right impedance for the travel mode you are modeling.

Choose from the following impedance values:

  • Drive Time—Models travel times for a car. These travel times are dynamic and fluctuate according to traffic flows in areas where traffic data is available. This is the default value.

  • Truck Time—Models travel times for a truck. These travel times are static for each road and don't fluctuate with traffic.

  • Walk Time—Models travel times for a pedestrian.

  • Travel Distance—Stores length measurements along roads and paths. To model walk distance, choose this option and ensure Walking is set in the Restriction parameter. Similarly, to model drive or truck distance, choose Travel Distance here and set the appropriate restrictions so your vehicle travels only on roads where it is permitted to do so.

The value you provide for this parameter is ignored unless Travel Mode is set to Custom, which is the default value.

If you choose Drive Time, Truck Time, or Walk Time, the Measurement Units parameter must be set to a time-based value; if you choose Travel Distance for Impedance, Measurement Units must be distance-based.

String
Service_Areas
(Optional)

Please ignore this parameter—it is for internal use only.

Feature Class

Code Sample

GenerateServiceAreas example

The following Python script demonstrates how to use the GenerateServiceAreas tool in a script.

import arcpy
import time
import sys

username = "<your user name>"
password = "<your password>"
sa_service = "http://logistics.arcgis.com/arcgis/services;World/ServiceAreas;{0};{1}".format(username, password)


#Add the geoprocessing service as a toolbox. Use an alias when importing
arcpy.ImportToolbox(sa_service, "agol")

#Set the variables to call the tool
facilities = r"C:/data/Inputs.gdb/Stores"
output_service_areas = "C:/data/Results.gdb/StoreServiceAreas"

#Call the tool
result = arcpy.agol.GenerateServiceAreas(facilities, "5 10 15", "Minutes")

#Check the status of the result object every 0.5 seconds 
#until it has a value of 4(succeeded) or greater 
while result.status < 4:
    time.sleep(0.5)

#print any warning or error messages returned from the tool
result_severity = result.maxSeverity
if result_severity == 2:
    print "An error occured when running the tool"
    print result.getMessages(2)
    sys.exit(2)
elif result_severity == 1:
    print "Warnings were returned when running the tool"
    print result.getMessages(1)
    
#Get the output routes  and save to a local geodatabase
result.getOutput(0).save(output_service_areas)

Environments

This tool does not use any geoprocessing environments

Related Topics

3/25/2015