Service area analysis layer

This topic describes the service area analysis layer's feature classes and analysis properties.

Learn more about the service area solver

Facilities feature class

The Facilities feature class stores the input facilities around which the output service area polygons are created. You can provide input field values that the service area analysis layer will reference when solving the analysis; the feature class also stores output field values once the analysis is complete.

The following tables describe the input fields and input/output fields of the Facilities feature class:

Facilities: Input fields

Input fieldDescription

ObjectID

The system-managed ID field.

Shape

The geometry field indicating the geographic location of the network analysis object.

Name

The name of the network analysis object.

Attr_[Cost]

(For instance, Attr_Minutes, where Minutes is the travel cost)

This field stores the additional time, distance, or other travel cost for the facility. Adding a value to this field reduces the reach of the service area.

If you're finding the service areas for three facilities using the DriveTime impedance attribute as the cost, the Attr_DriveTime field can be used to store the amount of time spent at the facility.

For example, when calculating service areas that represent fire station response times, the Attr_DriveTime field can store the turnout time, which is the time it takes a crew to put on the appropriate protective equipment and exit the fire station, for each fire station. Assume Fire Station 1 has a turnout time of 1 minute and Fire Station 2 has a turnout time of 3 minutes. If a 5-minute service area is calculated for both fire stations, the actual service area for Fire Station 1 would be 4 minutes (since 1 of the 5 minutes would be required as turnout time). Similarly, Fire Station 2 would have a service area of only 2 minutes from the fire station.

Service areas with different drive time values

The value you enter affects the analysis only when the [Cost] part of the field name (Attr_[Cost]) matches the cost attribute chosen for the analysis layer or travel mode. For example, if you add a 5 to Attr_DriveMinutes, but the cost attribute used in the analysis is TruckTime, the additional 5 minutes aren't included in the analysis results; however, if you change the network cost attribute to DriveMinutes, which corresponds with Attr_DriveMinutes, the 5 minutes you entered are added to the results.

Breaks_[Cost]

(For instance, Breaks_DriveTime, where DriveTime is the travel cost for the network)

You can store different polygon break values for each service area facility in the Breaks_[Cost] field. Given two facilities, this means you can generate 5- and 10-minute service area polygons for one facility and 6-, 9-, and 12-minute polygons for another facility.

Service areas with different polygon breaks for different facilities

Multiple breaks should be specified using a space-separated string. For example, to specify 6-, 9-, and 12-minute polygons for a given facility, the field value should be 6 9 12.

The value specified in the Breaks_[Cost] field overrides the Cutoffs analysis layer setting. If no value for the Breaks_[Cost] field is specified, service area polygons are generated for the facility based on the Cutoffs setting.

Caution:

Per-facility breaks are ignored if the analysis is configured with a polygon boundary type of Dissolve.

Network location fields

  • SourceID
  • SourceOID
  • PosAlong
  • SideOfEdge
  • SnapX
  • SnapY
  • SnapZ
  • DistanceToNetworkInMeters

Together, these properties describe the point on the network where the object is located.

Learn more about locating inputs on a network

CurbApproach

The CurbApproach field specifies the direction a vehicle may arrive at and depart from the facility. If the curb approach is confined to one side of the vehicle, it could further limit the reach of the service area.

There are four options for the CurbApproach value:

  • Either side of vehicle (0)—The service area can begin or end at the facility such that the facility is on the right or left side of the vehicle.

    The following graphic illustrates departing a facility from either side of a vehicle:

    CurbApproach set to Either side of vehicle.

  • Right side of vehicle (1)—The service area can begin or end at the facility such that the facility is on the right side of the vehicle.

    The following graphic illustrates departing a facility from the right side of a vehicle:

    CurbApproach set to Right side of vehicle (North American driving style).

  • Left side of vehicle (2)—The service area can begin or end at the facility such that the facility is on the left side of the vehicle.

    The following graphic illustrates departing a facility from the left side of a vehicle:

    CurbApproach set to Left side of vehicle.

  • No U-Turn (3)—For service areas, this option functions the same as Either side of vehicle.

Learn more about U-turns and curb approach

Facilities: Input/output fields

Input/output fieldDescription

Status

Indicates the status of the point with respect to its location on the network and the outcome of the analysis. The possible values are the following:

  • 0 (OK)—The point was located on the network.
  • 1 (Not Located)—The point was not located on the network and consequently was not included in the analysis.
  • 2 (Network element not located)—The network element identified by the point's network location fields can't be found. This can occur when a network element where the point should be was deleted, and the network location was not recalculated.
  • 3 (Element not traversable)—The network element that the point is located on is not traversable. This can occur when the element is restricted by a restriction attribute.
  • 4 (Invalid Field Values)—Field values fall outside a range or coded-value domain. For example, a negative number exists where positive numbers are required.
  • 5 (Not Reached)—The point can't be reached by the solver. The point may be on a separate, disconnected area of the network from the other inputs, or barriers or restrictions prevent travel to or from the point.
  • 6 (Time window violation)—The point could not be reached within the designated time windows. This status only applies to network analysis types that support time windows.
  • 7 (Not located on closest)—The closest network location to the point is not traversable because of a restriction or barrier, so the point has been located on the closest traversable network feature instead.

Polygons feature class

The Polygons feature class stores the resultant service area polygons, which cover the areas of the network that can be reached within the given time, distance, or other travel-cost cutoff. This feature class doesn't provide inputs to the analysis layer—it stores output information only.

To generate the Polygons feature class, on the Service Area Layer tab, in the Output Geometry group, set Output Shape Type to Polygons Polygons or Polygons and Lines Polygons and Lines.

Polygons: Output fields

The following table lists the output fields of the Polygons feature class:

Output fieldDescription

ObjectID

The system-managed ID field.

Shape

The geometry of the polygon, which is stored internally.

Name

The name of the service area polygon is based on the name of the associated facility and the cutoff range; for instance, Headquarters : 0.0 – 5.0 would represent a polygon that covers all traversable edges within 5 minutes from the facility, Headquarters.

FacilityID

The unique ID of the associated facility.

FromBreak

The lower bound of the polygon's break range.

ToBreak

The upper bound of the polygon's break range.

Lines feature class

The Lines feature class stores the resultant service areas as linear features and covers the streets, or network edges, that can be reached within the given time, distance, or other travel-cost cutoff. Lines are a truer representation of a service area than polygons since service area analyses are based on measurements along the network lines.

The Lines feature class doesn't provide inputs to the analysis layer; it serves to store outputs only.

Service area lines are not generated by default during a service area analysis, but you can choose to generate them. On the Service Area Layer tab, in the Output Geometry group, set Output Shape Type to Lines Lines or Polygons and Lines Polygons and Lines.

Lines: Output fields

The following table lists the output fields of the Lines feature class:

Output fieldDescription

ObjectID

The system-managed ID field.

Shape

The geometry of the line, which is stored internally.

FacilityID

The unique ID of the associated facility.

FromCumul_[Cost]

(for instance, FromCumul_Miles, where Miles is the travel cost)

This field contains the cumulative cost of the path from the facility to the beginning of the line feature. The cost of the adjacent junction at the beginning of the line is included in this value. This field is generated for the cost attribute and any accumulation attributes.

ToCumul_[Cost]

(for instance, ToCumul_Miles, where Miles is the travel cost)

This field contains the cumulative cost of the path from the facility to the end of the line feature. The cost of the adjacent junction at the end of the line is excluded from this value. This field is generated for the cost attribute and any accumulation attributes.

SourceID

Each service area line traverses a feature from a network source feature class—a feature class used to create the network dataset on which the service area analysis is performed. This field specifies the unique ID of the source feature class the traversed feature is a part of.

SourceOID

The ObjectID of the underlying source feature that is traversed by the service area.

FromPosition

Specifies where along the underlying source feature the service area line begins.

  • A value of 0 (zero) indicates the service area line begins at the from point of the underlying source feature.
  • A value of 1 indicates the service area line begins at the to point of the source feature.
  • A value between 0 and 1 indicates the line begins at a point along the underlying source feature; for example, a value of 0.25 means the line begins 25 percent along the digitized direction of the underlying source feature.

ToPosition

Specifies where along the underlying source feature the service area line ends.

  • A value of 0 (zero) indicates the service area line ends at the from point of the underlying source feature.
  • A value of 1 indicates the service area line ends at the to point of the source feature.
  • A value between 0 and 1 indicates the line ends at a point along the underlying source feature; for example, a value of 0.25 means the line ends 25 percent along the digitized direction of the underlying source feature.

Service area analysis layer properties

The following subsections list properties you can set on the analysis layer. They are on the Service Area Layer tab, which is available only if your service area layer or one of its sublayers is selected in the Contents pane.

Analysis

Use the options in this section to estimate the credits and run the analysis.

Analysis section

Run

Once you load input features and set analysis properties, click the Run button to run the analysis. If the analysis uses credits, and the number of credits estimated for the solve exceeds the available credits, you will see an error message that blocks the solve or a warning message that will allow you to choose whether to proceed with the solve.

The run button may appear different based on the source of the network dataset.

  • Run—The network analysis layer is referencing a local network data source.
  • Run Service—The network analysis layer is referencing a network data source in ArcGIS Online.
  • Run—The network analysis layer is referencing a network data source in an enterprise portal.

Estimate Credits

The Estimate Credits button can be used to estimate the number of service credits that will be consumed by running the analysis on the selected network analysis layer. When this button is enabled, it indicates that the network analysis layer will consume credits when solved.

Estimate Credits enabled

The Estimate Credits button is enabled when the following occur:

Estimate Credits disabled

The Estimate Credits button is disabled when the following occur:

When you click the Estimate Credits button, a dialog box appears with an estimate of how many credits are likely to be consumed solving the current analysis. The credit is estimated based on the number of input locations used in the analysis. The actual credits consumed may change based on the output generated by the Solve operation. Depending on how your organization has set up the credit budgeting and allocation settings, the available credits may not be shown. Also, credit estimation may not always be possible if the network data source is an ArcGIS Enterprise portal with routing services configured from ArcGIS Online.

Learn more about the credit usage by each analysis type

Estimated credit consumption and total credits available
Note:

Depending on the configuration of the ArcGIS Online organization account and the signed-in user, solving the analysis may be blocked or may show a warning if the estimated credits exceed the available credits.

Input Data

Use the options in this section to import the input features that should participate in the analysis.

Input Data section

Import Facilities

Use Import Facilities Import Facilities to load features from another data source, such as a point feature layer, into the Facilities feature class.

Import Barriers

Use the Import Point Barriers Import Point Barriers, Import Line Barriers Import Line Barriers, or Import Polygon Barriers buttons Import Barriers to load features from another data source, such as another feature layer, into one of the barriers feature classes (point barriers, line barriers, or polygon barriers).

Create Features

Use the Create Features button Create Features to open the Create Features pane. Select from the available templates to create features in the current map.

Travel Settings

Use the options from this section to select the travel mode and optimize the route.

Travel Settings section

Mode

The Mode drop-down list allows you to choose a travel mode, which is a group of settings that together model the movement of pedestrians, cars, trucks, or another travel mode. The choices available in the drop-down list depend on the travel modes that are configured on the network data source that the network analysis layer is referencing.

Direction

You can choose to create a service area by accumulating travel time or other cost in the direction away from or toward the facilities, as follows:

  • Away from facilities Away from facilities—The service areas are measured from the facilities out to the periphery.
  • Toward facilities Toward facilities—The service areas are measured from the periphery toward the facilities.

On a network with one-way restrictions and different travel times based on direction of travel, this would result in different service areas. 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 for travel that spans out from the facility (Away from facilities) since pizzas are delivered from the store to the customer. Alternatively, a hospital would choose Toward facilities since the urgent part of the trip for a patient is going to the hospital, not returning home afterward.

If there is any service time at a facility (that is, the facility's Attr_[Cost] field has a positive value), the service time is included in the results immediately before the finish time when travel is toward facilities, or immediately after the start time when travel is away from facilities.

Cutoffs

The extent of the service area to be calculated is specified with the Cutoffs text box. For instance, a cutoff of 10 creates service areas of 10 units (for instance, 10 minutes or 10 miles) from the facilities. The unit for the chosen travel mode is indicated to the right of the Mode drop-down list.

A 10-minute service area polygon

The Cutoffs property is used when a facility's Breaks_[Cost] field value is null. Suppose you have two facilities, A and B, for which you want to find a drive-time area. Facility A has a Breaks_DriveTime value of 3. Facility B has no value for its Breaks_DriveTime field. When you find the service area with Cutoffs set to 5 (minutes), facility A will have a 3-minute service area, and facility B will have a 5-minute service area.

Override and default cutoffs

Note:

Cutoffs assigns default values to facilities that do not have numeric values stored in the Break_[Cost] field.

Multiple polygon breaks can be set to create concentric service areas. For instance, if you want to find 2-, 3-, and 4-minute service areas for each facility, you would type 2, 3, 4 in the Cutoffs text box.

2-, 3- and 4-minute service areas

Accumulate Cost Attributes

The Accumulate Cost Attributes drop-down menu Accumulate Cost Attributes button can be used to configure accumulated cost attributes. The drop-down menu is unavailable if the network data source is a service, the output geometry types do not include lines, or there are no cost attributes. The attributes are grouped by unit domain shown as the group header (for example, Time or Distance). A checked check box indicates that the analysis layer will accumulate the checked attribute during the solve.

Accumulate Cost Attributes drop-down menu

When multiple analysis layers of the same layer type are selected, the check box shows a mixed state if all layers do not share the same checked status for one attribute. In the following image, the WeekendFallbackTravelTime attribute is selected for multiple layers, so it has a check mark.

Check box showing a mixed state

If all selected layers share the checked status for an attribute, the check box shows that state.

Check boxes are checked for the attributes.

Date and Time

Use the options from the Date and Time section to specify the date, time, and day that should be used in the analysis.

Date and Time section

Learn more about date and time

Arrive Depart Date-Time Type

The Arrive Depart Date-Time Type drop-down list is available when the cost units are time based. From the drop-down list, choose whether a specific time and date value is given to indicate the time that the route or routes depart from their first stop. The primary reason for setting a specific time and date is to solve the analysis using dynamic traffic conditions or public transit schedules; however, to use traffic or public transit in the analysis, the network dataset or route service must include traffic data or public transit.

The options in the drop-down list are as follows:

  • Not Using Time—Regardless of whether the network data source includes time-based data, the results are based on static travel times—the travel times on a network edge don't vary throughout the day. The Time of Day and Date text boxes are unavailable.

  • Date & Time—Specify the time as a time of day and calendar date. The Time of Day and Date text boxes are available to provide this information.

  • Day of Week—Specify a time of day and day of the week. The Time of Day and Date text boxes are available to provide this information.

  • Today—Specify a time, and the day is assumed to be the current date. The Time of Day text box is available to provide the time of day, and the Date text box is set to Today and is unavailable so it can't be changed.

  • Now—When you run the analysis, the time and date are set to the current time and date. This is useful if your network dataset is configured with live traffic data, and the routes are distributed to drivers for implementing immediately after running the analysis. The Time of Day and the Date text boxes are unavailable so they can't be changed.

Time of Day

Specify the depart time of the day.

See the Arrive Depart Date-Time Type section to see when this option is enabled.

Date

Specify the depart day of the week by typing one of the following values in the Date text box:

  • Monday
  • Tuesday
  • Wednesday
  • Thursday
  • Friday
  • Saturday
  • Sunday

See the Arrive Depart Date-Time Type section to see when this option is enabled.

Reference Time Zone

From the Reference Time Zone drop-down list Reference Time Zone button, you can choose which time zone to use in the analysis. The options are as follows:

  • Local Time at Locations
  • UTC (Universal Coordinated Time)

Output Geometry

Use the options from this section to specify how the output will display in the map.

Output Geometry section

Polygons, Lines, and Polygons and Lines

Choose whether to generate polygons Polygons, lines Lines, or polygons and lines Polygons and Lines as output.

Lines and Polygon and Lines output is not available if the network data source is a service on a version of Portal for ArcGIS that does not support generating lines.

Polygon Detail Level

You can specify the level of detail you want for output polygons by setting the Polygon Detail Level property.

  • Generalized—This option is available when your network dataset includes a hierarchy attribute.

    In a hierarchical service area analysis, the solver prefers higher-order edges to the lowest-order edges. This means that if a facility is located on a local road (the lowest level in a hierarchy), the solver spans out on the local roads in that area, but it tries to step up the hierarchy to secondary and primary roads. Once on secondary and primary roads, the solver ignores local roads throughout the rest of the service area. It ignores secondary and local roads once it has stepped up to primary roads. Mainly because of this hierarchical approach, nonhierarchical service areas tend to be superior in quality to their hierarchical counterparts.

    Generalized

  • Standard Precision—Standard polygons are generated quickly and are fairly accurate, but quality deteriorates somewhat as you move toward the borders of the service area polygons. Outputting standard-detail polygons may result in islands of unreached network elements, such as roads, being covered.

    Standard precision

  • High Precision—Choose this option to get the most detailed polygons. Holes within the polygon may exist; they represent islands of network elements that couldn't be reached without exceeding the cutoff impedance or due to travel restrictions. Expect high-precision polygons to take the longest amount of time to generate.

    You will get holes only if you use High Precision polygons and the Overlap or Dissolve output geometry setting. The Split setting will not generate holes within the polygons.

    High precision

Tip:

Creating a service-area index on your network dataset can optimize processing time and improve the quality of standard- and high-precision polygons.

Boundary type

There are several options available for generating polygons or lines for multiple facilities:

  • Overlap—This option creates individual polygons for each facility. The polygons can overlap each other.
    Overlapping polygons
    For overlapping lines, portions of the network that are within reach of more than one facility will have a line for each facility.
    Overlapping lines
  • Dissolve—This option merges the polygons of multiple facilities that have the same cutoff values into one polygon. If the polygons of a given break value don't touch, they are nonetheless merged into one multipart polygon. This option does not apply to lines.
    Dissolved polygons
  • Split—This option creates individual polygons that are closest for each facility. The polygons do not overlap each other.
    Split polygons
    For split lines, none of the lines overlap each other, and a line is always assigned to the nearest facility even if more than one facility can reach it.
    Split lines

Polygon rings or disks

You can choose to create concentric service area polygons as disks or rings.

  • Rings—Output polygons extend between the nearest cutoff values only. They do not include the area of smaller breaks. This creates polygons between consecutive breaks.
    Rings
  • Disks—Output polygons extend from the facility to the cutoff. If you create 5- and 10-minute service areas, the 10-minute service area polygon will include the area under the 5-minute service area polygon as well as the area from the 5-minute to the 10-minute break.
    Disks

Exclude Edge Sources

You can use the Exclude Edge Sources drop-down menu Exclude Edge Sources and choose to exclude certain network dataset edge sources when generating service area polygons. Polygons will not be generated around the excluded sources, even though they are traversed in the analysis.

Excluding a network source from service area polygons does not prevent those sources from being traversed. Excluding sources from service area polygons only influences the polygon shape of the service areas. To prevent traversal of a given network source, you must create an appropriate restriction when defining your network dataset.

This is useful if you have some network sources that you don't want to be included in the polygon generation because they create less-accurate polygons or are inconsequential for the service area analysis. For example, while creating a walk-time service area in a multimodal network that includes streets and metro lines, you should choose to exclude the metro lines from polygon generation. Although the traveler can use the metro lines, they cannot stop partway along a metro line and enter a nearby building. Instead, they must travel the full length of the metro line, exit the metro system at a station, then use the streets to walk to the building. It would be inaccurate to generate a polygon feature around a metro line.

This parameter is not available when the output geometry types do not include polygons, there are fewer than two edge sources in the network, the network data source is an ArcGIS Online service, or the network data source is a service on a version of Portal for ArcGIS that does not support excluding sources.

Polygon Trim Distance

Polygon Trim Distance Polygon Trim Distance controls how close service area polygons should be from the reached network edges. The trim distance refers to the distance from the road the service area polygon should extend when no other reachable roads are nearby, similar to a line buffer size. It roughly models how far back from the road centerlines is considered reachable from the road. This is useful if the network is very sparse and you don't want the service area to cover large areas where there are no features.

The parameter includes a value and units for the distance. The default value is 100 meters. This parameter is disabled in the following situations:

  • The Output Shape Types parameter is set to Lines.
  • The Polygon Detail Level parameter is set to Generalized.

Drawing

Use the Symbology button Symbology to access the symbology pane for the active network analysis layer. You can configure the symbology for the sublayers of the active network analysis layer by choosing one of the following options:

  • Single Color—This option is available for all network analysis layer types. All feature sublayers in the active network analysis layer except barriers will use the same single symbol with the specified color. For example, choosing a single color of blue for a Route layer will convert all the Stops and the Routes features to the same color of blue.
  • Color Linked—This option is available for Route and Vehicle Routing problem layers. It applies a color scheme to the sublayers such that related features are symbolized with the same color. This symbology configuration symbolizes related features with the same color, making it easier to visually distinguish different routes and their associated features in the map. For example, for a Route layer with multiple routes, each route and the stops assigned to that route will be assigned matching colors.

Learn more about network analysis layer symbology