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The value specified in the Breaks_ property overrides the Default Breaks analysis layer setting. 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. You can store different polygon break values for each service area facility in the Breaks_ property. (for instance, Breaks_DriveTime, where DriveTime is the impedance for the network) Similarly, Fire Station 2 would have an actual service area of only two minutes. If a 5-minute service area is calculated for both fire stations, the actual service area for Fire Station 1 would be three minutes (since two of the five minutes would be required as turnout time). Assume Fire Station 1 has a turnout time of two minutes and Fire Station 2 has a turnout time of three minutes. Adding a value to this property reduces the reach of the service area.įor example, if you are finding the service area for three facilities using drive time as impedance, the property Attr_DriveTime can be used to store the amount of time spent at the facility.įor example, when calculating service areas that represent fire station response times, Attr_DriveTime can store the turnout time, which is the time it takes a crew to don the appropriate protective equipment and exit the fire station, for each fire station.
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This property stores the value of impedance for the facility it is sometimes called the delay impedance. (for instance, Attr_Minutes, where Minutes is a cost attribute on the network) The geometry field indicating the geographic location of the network analysis object. Facility properties Input fields of facilities Input field At least one facility is necessary to create a service area. It is populated only when network locations are added into it. When a new service area analysis layer is created, the Facilities class is empty.
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You can modify the symbology of the Facilities layer in the Layer Properties dialog box. The Facilities feature layer has three default symbols: Located, Unlocated, and Error. This network analysis class stores the network locations that are used as facilities in service area analysis. Learn more about network analysis classes Facilities class Service area analysis classesĪn overview of each class and descriptions of their properties are provided in the following sections. There are six feature layers, which have default symbology that can be modified in their respective Layer Properties dialog boxes. The service area analysis layer also appears in the table of contents as a composite layer that is named Service Area or if a service area with the same name already exists in the map, Service Area 1, Service Area 2, and so on. When you create the service area analysis layer, it shows up in the Network Analyst window, along with its six network analysis classes-Facilities, Lines, Polygons, Point Barriers, Line Barriers, and Polygon Barriers. You can create a service area analysis layer from the Network Analyst toolbar by clicking Network Analyst > New Service Area. The service area analysis layer stores all the inputs, parameters, and results of a service area analysis. Learn more about the network analysis workflow Service area analysis layer Once service areas are created, you can use them to identify how much land, how many people, or how much of anything else is within the neighborhood or region.įinding the network-based service area follows the same workflow as other network analyses. Concentric service areas show how accessibility varies with impedance. Service areas created by Network Analyst also help evaluate accessibility. For instance, the 5-minute service area for a point on a network includes all the streets that can be reached within five minutes from that point. A network service area is a region that encompasses all accessible streets (that is, streets that are within a specified impedance). With the ArcGIS Network Analyst extension, you can find service areas around any location on a network.