Generate Service Areas Tool
أداة إنشاء مناطق الخدمة
ArcMap ArcGIS
How to use Generate Service Areas Tool in Arc Toolbox ArcMap ArcGIS??
كيفية استخدام أداة إنشاء مناطق الخدمة ؟؟
Path to access the toolمسار الوصول الى الأداة
:
Generate Service Areas Tool,
Server Toolset, Network Analyst Tools Toolbox
Generate Service Areas
ينشئ طبقة تحليل شبكة منطقة الخدمة ، ويعين خصائص
التحليل ، ويحل التحليل. هذه الأداة مثالية لإعداد خدمة معالجة جغرافية لمنطقة
خدمة على الويب. منطقة خدمة الشبكة هي منطقة تشمل جميع الشوارع التي يمكن الوصول
إليها ضمن مسافة معينة أو وقت السفر من واحد أو أكثر من المرافق.
تُستخدم مناطق الخدمة بشكل شائع لتصور وقياس
إمكانية الوصول. على سبيل المثال ، يمكن لمضلع زمن القيادة لمدة 3 دقائق حول محل
بقالة تحديد السكان القادرين على الوصول إلى المتجر في غضون 3 دقائق وبالتالي من
المرجح أن يتسوقوا هناك.
تتشابه أدوات إنشاء مناطق الخدمة وإنشاء طبقة
منطقة الخدمة ، لكنها مصممة لأغراض مختلفة. استخدم إنشاء مناطق الخدمة إذا كنت
تقوم بإعداد خدمة معالجة جغرافية ؛ سوف يبسط عملية الإعداد ؛ خلاف ذلك ، استخدم Make Service Area Layer. أيضًا ، استخدم Make Service Area Layer إذا
كنت بحاجة إلى إنشاء خطوط منطقة الخدمة ؛ لا يوفر إنشاء مناطق الخدمة خيار إنشاء
الخطوط.
لإنشاء خدمة معالجة جغرافية لمنطقة خدمة باستخدام
إنشاء مناطق خدمة ، ما عليك سوى إعداد أداة واحدة ، ويمكنك نشر الأداة مباشرةً
كخدمة. في المقابل ، تحتاج إلى إنشاء نموذج باستخدام إنشاء طبقة منطقة الخدمة ،
وتوصيله بشكل صحيح بالعديد من الأدوات الأخرى ، ونشر النموذج لإنشاء خدمة معالجة
جغرافية لمنطقة الخدمة. انظر مثال خدمة المعالجة الجغرافية: مضلعات وقت القيادة
لمعرفة كيفية إعداد خدمة مضلعات وقت القيادة باستخدام بيانات البرنامج التعليمي.
أحد الخيارات الأخرى التي يجب مراعاتها هو خدمة ArcGIS Online Generate Service Area. تعمل الخدمة كأداة
معالجة جغرافية في ArcMap ، ويمكن الوصول إليها من
تطبيقات أخرى ، وتتضمن بيانات طريق عالية الجودة لمعظم أنحاء العالم.
Facilities
The facilities around which service areas are generated.
The facilities feature set has three attributes:
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the facility. If the name is empty, blank, or null, a name is
automatically generated at solve time.
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.
When the Generate Service Areas tool runs, a noteworthy interaction occurs
among the following parameters: Break Values, Break Units, and either Time
Attribute or Distance Attribute. Together, Break Values and Break Units define
how far or how long the service area should extend around the facility or
facilities. The Time Attribute and Distance Attribute parameters each define
one network cost attribute. Only one of these two cost attributes is used,
however, and the one that the solver chooses to use corresponds with the Break
Units value; that is, when you specify a time-based Break Units value, such as
seconds or minutes, the tool solves using the cost attribute defined in the
Time Attribute parameter. When you specify a distance-based Break Units value,
such as kilometers or miles, it uses the cost attribute defined in the Distance
Attribute parameter.
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, enter 2 3 5, separating the values with a space. Set Break Units to
Miles and ensure that you have chosen a distance-based network attribute for
the Distance Attribute parameter.
Break Units
The units for the Break Values parameter.
· Meters
· Kilometers
· Feet
· Yards
· Miles
· Nautical Miles
· Seconds
· Minutes
· Hours
· Days
The Generate Service Areas tool chooses whether to use the network cost
attribute specified in the Time Attribute or Distance Attribute parameter
depending on whether the units you specify here are time or distance based.
The tool performs the necessary units conversion when the Break Units
value differs from the units of the corresponding time or distance cost
attribute.
Network Dataset
The network dataset on which the analysis will be performed. Network
datasets most often represent street networks but may represent other kinds of
transportation networks as well. The network dataset needs at least one
time-based and one distance-based cost attribute.
Service Areas
The output workspace and name of the output features. This workspace must
already exist. The default output workspace is in_memory.
Travel Mode (optional)
Choose the mode of transportation for the analysis. Custom is always a
choice. For other travel mode names to appear, they must be present in the
network dataset specified in the Network Dataset parameter.
A travel mode is defined on a network dataset and provides override values
for parameters that, together, model cars, trucks, pedestrians, or other modes
of travel. By choosing a travel mode here, you don't need to provide values for
the following parameters, which are overridden by values specified in the
network dataset:
· UTurn Policy
· Time Attribute
· Time Attribute Units
· Distance Attribute
· Distance Attribute Units
· Use Hierarchy in Analysis
· Restrictions
· Attribute Parameter Values
· Polygon Simplification Tolerance
· CUSTOM—Define a travel mode that fits your specific needs. When Custom is
chosen, the tool does not override the travel mode parameters listed above.
This is the default value.
Travel Direction (optional)
Choose whether the direction of travel used to generate the service area
polygons is toward or away from the facilities.
· TRAVEL_FROM—The service area is generated in the direction away from the
facilities.
· TRAVEL_TO—The service area is created in the direction toward the
facilities.
The direction of travel may change the shape of the polygons because
impedances on opposite sides of a street may differ, or one-way streets may
exist. 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 since the critical travel time for a patient is
traveling to the hospital.
Time of Day (optional)
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 travel away
from facilities.
· It represents the arrival time if Travel Direction is set to travel toward
facilities.
Your network dataset must include traffic data for this parameter to have
any effect.
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 5-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.
Time Zone for Time of Day
(optional)
Specifies the time zone or zones of the Time of Day parameter.
· GEO_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 or zones they are 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.
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.
Overrides (optional)
Additional settings that can be used to influence the behavior of the
solver.
The value for this parameter is specified in JavaScript Object Notation
(JSON) using the form {"overrideSetting1" : "value1",
"overrideSetting2" : "value2"}. The override setting names
are always enclosed in double quotation marks. The values can be a number,
Boolean, or a string.
Overrides are advanced settings that should be used only with careful
analysis of the results obtained before and after applying the settings. A list
of supported override settings for each solver and their acceptable values can
be obtained by contacting Esri Technical Support.
Point Barriers (optional)
Specifies point barriers, which are split into two types: restriction and
added cost point barriers. They temporarily restrict traversal across or add
impedance to points on the network. The point barriers are defined by a feature
set, and the attribute values you specify for the point features determine
whether they are restriction or added cost barriers. The fields in the
attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or adds cost
when traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through the barrier. This is the
default value.
· Added Cost (2)—Traversing through the barrier increases the network cost
by the amount specified in the Additional_Time and Additional_Distance fields.
Use the value 0 for Restriction and 2 for Added Cost.
AdditionalCost:
AdditionalCost indicates how much impedance is added when a service area
passes through the barrier.
The unit for this field value is the same as the units specified for Break
Units.
Line Barriers (optional)
Specifies line barriers, which temporarily restrict traversal across them.
The line barriers are defined by a feature set. The fields in the attribute
table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
Polygon Barriers (optional)
Specifies polygon barriers, which are split into two types: restriction
and scaled cost polygon barriers. They temporarily restrict traversal or scale
impedance on the parts of the network they cover. The polygon barriers are
defined by a feature set, and the attribute values you specify for the polygon
features determine whether they are restriction or scaled cost barriers. The
fields in the attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or scales the
cost of traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through any part of the barrier. This
is the default value.
· Scaled Cost (1)—Scales the impedance of underlying edges by multiplying
them by the value of the ScaledCostFactor property. If edges are partially
covered by the barrier, the impedance is apportioned and multiplied.
Use the value 0 for Restriction and 1 for Scaled Cost.
ScaledCostFactor:
ScaledCostFactor indicates how much the impedance is multiplied by when a
service area passes through the barrier.
UTurn Policy (optional)
The U-Turn policy at junctions. Allowing U-turns implies the solver can
turn around at a junction and double back on the same street. Given that
junctions represent street intersections and dead ends, different vehicles may
be able to turn around at some junctions but not at others—it depends on
whether the junction represents an intersection or dead end. To accommodate
this, the U-turn policy parameter is implicitly specified by how many edges
connect to the junction, which is known as junction valency. The acceptable
values for this parameter are listed below; each is followed by a description
of its meaning in terms of junction valency.
· ALLOW_UTURNS—U-turns are permitted at junctions with any number of
connected edges. This is the default value.
· NO_UTURNS—U-turns are prohibited at all junctions, regardless of junction
valency. Note, however, that U-turns are still permitted at network locations
even when this setting is chosen; however, you can set the individual network
location's CurbApproach property to prohibit U-turns there as well.
· ALLOW_DEAD_ENDS_ONLY—U-turns are prohibited at all junctions, except those
that have only one adjacent edge (a dead end).
· ALLOW_DEAD_ENDS_AND_INTERSECTIONS_ONLY—U-turns are prohibited at junctions
where exactly two adjacent edges meet but are permitted at intersections
(junctions with three or more adjacent edges) and dead ends (junctions with
exactly one adjacent edge). Often, networks have extraneous junctions in the
middle of road segments. This option prevents vehicles from making U-turns at
these locations.
If you need a more precisely defined U-turn policy, consider adding a
global turn delay evaluator to a network cost attribute, or adjusting its
settings if one exists, and pay particular attention to the configuration of
reverse turns. Also, look at setting the CurbApproach property of your network
locations.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
time unit.
The tool performs the necessary time-unit conversion when the Break Units
value differs from the units of the cost attribute defined here. In other
words, the time units of the breaks and the network cost attribute don't need
to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute Units (optional)
The units of the network cost attribute specified by the Time Attribute
parameter. This is merely an informational parameter that cannot be changed
without directly editing the network dataset. It is also unnecessary to change
since the unit conversions between break value units and the cost attribute are
handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
distance unit.
The tool performs the necessary distance-unit conversion when the Break
Units value differs from the units of the cost attribute defined here. In other
words, the distance units of the breaks and the network cost attribute don't need
to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute Units
(optional)
The units of the network cost attribute specified by the Distance
Attribute parameter. This is merely an informational parameter that cannot be
changed without directly editing the network dataset. It is also unnecessary to
change since the unit conversions between break value units and the cost
attribute are handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Use Hierarchy in Analysis
(optional)
· Checked—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. This option is enabled only if the
input network dataset has a hierarchy attribute.
· Unchecked—Do not use the hierarchy attribute for the analysis. Not using a
hierarchy yields an exact route for the network dataset.
The parameter is disabled if a hierarchy attribute is not defined on the
network dataset used to perform the analysis.
You can use the Force Hierarchy Beyond Distance parameter to force the
solver to use hierarchy even if Use Hierarchy in Analysis is set to false.
This parameter is ignored unless Travel Mode is set to Custom. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
· USE_HIERARCHY— 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. This option is valid only if the
input network dataset has a hierarchy attribute.
· NO_HIERARCHY—Do not use the hierarchy attribute for the analysis. Not
using a hierarchy yields an exact route for the network dataset.
The parameter is not used if a hierarchy attribute is not defined on the
network dataset used to perform the analysis. In such cases, use "#"
as the parameter value.
You can use the Force_Hierarchy_Beyond_Distance parameter to force the
solve to use hierarchy even if Use_Hierarchy_in_Analysis is set to False.
This parameter is ignored unless Travel_Mode is set to CUSTOM. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
Restrictions (optional)
Indicates which network restriction attributes are respected during solve
time.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Attribute Parameter Values
(optional)
Specifies the parameter values for network attributes that have
parameters. The record set has two columns that work together to uniquely
identify parameters and another column that specifies the parameter value.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
The attribute parameter values record set has associated attributes. The
fields in the attribute table are listed below and described.
ObjectID:
The system-managed ID field.
AttributeName:
The name of the network attribute whose attribute parameter is set by the
table row.
ParameterName:
The name of the attribute parameter whose value is set by the table row.
(Object type parameters cannot be updated using this tool.)
ParameterValue:
The value you want for the attribute parameter. If a value is not
specified, the attribute parameter is set to null.
Polygon Simplification Tolerance
(optional)
Specify by how much you want to simplify the polygon geometry.
Simplification maintains critical points of a polygon to define its
essential shape and removes other points. The simplification distance you
specify is the maximum allowable offset from the original polygon from which
the simplified polygon can deviate. Simplifying a polygon reduces the number of
vertices and tends to reduce drawing times.
Maximum Snap Tolerance (optional)
The maximum snap tolerance is the furthest distance that Network Analyst
searches when locating or relocating a point onto the network. The search looks
for suitable edges or junctions and snaps the point to the nearest one. If a
suitable location isn't found within the maximum snap tolerance, the object is
marked as unlocated.
Exclude Restricted Portions of the
Network (optional)
· Checked—Facilities are only located on traversable portions of the
network. This prevents locating them on elements that can't be reached during
the solve process due to restrictions or barriers. Bear in mind that facilities
may be located farther from their intended location than if this option were
left unchecked.
· Unchecked—Facilities can be located on any of the elements of the network;
however, the facilities that are located on restricted elements cannot be used
during the solve process.
Feature Locator WHERE Clause
(optional)
An SQL expression used to select a subset of source features that limits
which network elements facilities can be located on. The syntax for this
parameter consists of two parts: the first is the source feature class name
(followed by a space), and the second is the SQL expression. To write an SQL
expression for two or more source feature classes, separate them with a
semicolon.
To ensure facilities are not located on limited-access highways, for
example, write an SQL expression like the following to exclude those source
features: "Streets" "FUNC_CLASS not in('1', '2')".
Note that barriers ignore the feature locator WHERE clause when loading.
Polygons for Multiple Facilities
(optional)
Choose how service area polygons are generated when multiple facilities
are present in the analysis.
· NO_MERGE—Creates individual polygons for each facility. The polygons can
overlap each other.
· NO_OVERLAP— 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— Creates and joins the polygons of different facilities that have
the same break value.
Polygon Overlap Type (optional)
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—Does not include the area of the 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.
· 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.
Detailed Polygons (optional)
Specifies whether to create detailed or generalized polygons.
· Checked—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.
· Unchecked—Creates generalized polygons, which are generated quickly and
are fairly accurate.
Polygon Trim Distance (optional)
Specifies the distance within which the service area polygons are trimmed.
This is useful when your data is very sparse and you don't want the service
area to cover large areas where there are no features.
No value or a value of 0 for this parameter specifies that the service
area polygons should not be trimmed. The parameter value is ignored when using
hierarchy.
Save Output Network Analysis Layer
(optional)
Choose whether the output includes a network analysis layer of the
results. In either case, a feature class with service area polygons is
returned. However, a server administrator may want to choose to output a
network analysis layer as well so the setup and results of the tool can be
debugged using the Network Analyst controls in the ArcGIS Desktop environment.
This can make the debugging process much easier.
In ArcGIS Desktop, the default output location for the network analysis
layer is in the scratch folder. You can determine the location of the scratch
folder by evaluating the value of the arcpy.env.scratchFolder geoprocessing
environment in the Python window. The output network analysis layer is stored
as an LYR file whose name starts with _ags_gpna and is followed by an
alphanumeric GUID.
Maximum Facilities (optional)
Limits how many facilities can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Number of Breaks
(optional)
Limits how many breaks can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Point
Barriers (optional)
Limits how many features can be affected by point barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Line
Barriers (optional)
Limits how many features can be affected by line barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by
Polygon Barriers (optional)
Limits how many features can be affected by polygon barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Time Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving time-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Distance Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving distance-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Force Hierarchy beyond Break Time
Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving time-based service areas.
Solving service areas for high break values while using the network's hierarchy
tends to incur much less processing than solving the same service areas without
using the hierarchy. This parameter helps you govern the amount of processing
that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
Force Hierarchy beyond Break
Distance Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving distance-based service areas.
Solving service areas for high break values while using the network's
hierarchy tends to incur much less processing than solving the same service
areas without using the hierarchy. This parameter helps you govern the amount
of processing that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
1.
Facilities خدمات
The facilities around
which service areas are generated.
المرافق التي يتم إنشاء مناطق الخدمة حولها.
مجموعة ميزات المرافق لها ثلاث سمات:
معرف الكائن:
حقل المعرف الذي يديره النظام.
شكل:
يشير الحقل الهندسي إلى الموقع الجغرافي لكائن
تحليل الشبكة.
اسم:
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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.
When the Generate Service Areas tool runs, a noteworthy interaction occurs
among the following parameters: Break Values, Break Units, and either Time
Attribute or Distance Attribute. Together, Break Values and Break Units define
how far or how long the service area should extend around the facility or
facilities. The Time Attribute and Distance Attribute parameters each define
one network cost attribute. Only one of these two cost attributes is used,
however, and the one that the solver chooses to use corresponds with the Break
Units value; that is, when you specify a time-based Break Units value, such as
seconds or minutes, the tool solves using the cost attribute defined in the
Time Attribute parameter. When you specify a distance-based Break Units value,
such as kilometers or miles, it uses the cost attribute defined in the Distance
Attribute parameter.
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, enter 2 3 5, separating the values with a space. Set Break Units to
Miles and ensure that you have chosen a distance-based network attribute for
the Distance Attribute parameter.
Break Units
The units for the Break Values parameter.
· Meters
· Kilometers
· Feet
· Yards
· Miles
· Nautical Miles
· Seconds
· Minutes
· Hours
· Days
The Generate Service Areas tool chooses whether to use the network cost
attribute specified in the Time Attribute or Distance Attribute parameter
depending on whether the units you specify here are time or distance based.
The tool performs the necessary units conversion when the Break Units
value differs from the units of the corresponding time or distance cost
attribute.
Network Dataset
The network dataset on which the analysis will be performed. Network
datasets most often represent street networks but may represent other kinds of
transportation networks as well. The network dataset needs at least one
time-based and one distance-based cost attribute.
Service Areas
The output workspace and name of the output features. This workspace must
already exist. The default output workspace is in_memory.
Travel Mode (optional)
Choose the mode of transportation for the analysis. Custom is always a
choice. For other travel mode names to appear, they must be present in the
network dataset specified in the Network Dataset parameter.
A travel mode is defined on a network dataset and provides override values
for parameters that, together, model cars, trucks, pedestrians, or other modes
of travel. By choosing a travel mode here, you don't need to provide values for
the following parameters, which are overridden by values specified in the
network dataset:
· UTurn Policy
· Time Attribute
· Time Attribute Units
· Distance Attribute
· Distance Attribute Units
· Use Hierarchy in Analysis
· Restrictions
· Attribute Parameter Values
· Polygon Simplification Tolerance
· CUSTOM—Define a travel mode that fits your specific needs. When Custom is
chosen, the tool does not override the travel mode parameters listed above.
This is the default value.
Travel Direction (optional)
Choose whether the direction of travel used to generate the service area
polygons is toward or away from the facilities.
· TRAVEL_FROM—The service area is generated in the direction away from the
facilities.
· TRAVEL_TO—The service area is created in the direction toward the
facilities.
The direction of travel may change the shape of the polygons because
impedances on opposite sides of a street may differ, or one-way streets may
exist. 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 since the critical travel time for a
patient is traveling to the hospital.
Time of Day (optional)
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 travel away
from facilities.
· It represents the arrival time if Travel Direction is set to travel toward
facilities.
Your network dataset must include traffic data for this parameter to have
any effect.
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 5-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.
Time Zone for Time of Day
(optional)
Specifies the time zone or zones of the Time of Day parameter.
· GEO_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 or zones they are 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.
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.
Overrides (optional)
Additional settings that can be used to influence the behavior of the
solver.
The value for this parameter is specified in JavaScript Object Notation
(JSON) using the form {"overrideSetting1" : "value1",
"overrideSetting2" : "value2"}. The override setting names
are always enclosed in double quotation marks. The values can be a number,
Boolean, or a string.
Overrides are advanced settings that should be used only with careful
analysis of the results obtained before and after applying the settings. A list
of supported override settings for each solver and their acceptable values can
be obtained by contacting Esri Technical Support.
Point Barriers (optional)
Specifies point barriers, which are split into two types: restriction and
added cost point barriers. They temporarily restrict traversal across or add
impedance to points on the network. The point barriers are defined by a feature
set, and the attribute values you specify for the point features determine
whether they are restriction or added cost barriers. The fields in the
attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or adds cost
when traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through the barrier. This is the
default value.
· Added Cost (2)—Traversing through the barrier increases the network cost
by the amount specified in the Additional_Time and Additional_Distance fields.
Use the value 0 for Restriction and 2 for Added Cost.
AdditionalCost:
AdditionalCost indicates how much impedance is added when a service area
passes through the barrier.
The unit for this field value is the same as the units specified for Break
Units.
Line Barriers (optional)
Specifies line barriers, which temporarily restrict traversal across them.
The line barriers are defined by a feature set. The fields in the attribute
table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
Polygon Barriers (optional)
Specifies polygon barriers, which are split into two types: restriction
and scaled cost polygon barriers. They temporarily restrict traversal or scale
impedance on the parts of the network they cover. The polygon barriers are
defined by a feature set, and the attribute values you specify for the polygon
features determine whether they are restriction or scaled cost barriers. The
fields in the attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or scales the
cost of traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through any part of the barrier. This
is the default value.
· Scaled Cost (1)—Scales the impedance of underlying edges by multiplying
them by the value of the ScaledCostFactor property. If edges are partially
covered by the barrier, the impedance is apportioned and multiplied.
Use the value 0 for Restriction and 1 for Scaled Cost.
ScaledCostFactor:
ScaledCostFactor indicates how much the impedance is multiplied by when a
service area passes through the barrier.
UTurn Policy (optional)
The U-Turn policy at junctions. Allowing U-turns implies the solver can
turn around at a junction and double back on the same street. Given that
junctions represent street intersections and dead ends, different vehicles may
be able to turn around at some junctions but not at others—it depends on
whether the junction represents an intersection or dead end. To accommodate
this, the U-turn policy parameter is implicitly specified by how many edges
connect to the junction, which is known as junction valency. The acceptable
values for this parameter are listed below; each is followed by a description
of its meaning in terms of junction valency.
· ALLOW_UTURNS—U-turns are permitted at junctions with any number of
connected edges. This is the default value.
· NO_UTURNS—U-turns are prohibited at all junctions, regardless of junction
valency. Note, however, that U-turns are still permitted at network locations
even when this setting is chosen; however, you can set the individual network
location's CurbApproach property to prohibit U-turns there as well.
· ALLOW_DEAD_ENDS_ONLY—U-turns are prohibited at all junctions, except those
that have only one adjacent edge (a dead end).
· ALLOW_DEAD_ENDS_AND_INTERSECTIONS_ONLY—U-turns are prohibited at junctions
where exactly two adjacent edges meet but are permitted at intersections
(junctions with three or more adjacent edges) and dead ends (junctions with
exactly one adjacent edge). Often, networks have extraneous junctions in the
middle of road segments. This option prevents vehicles from making U-turns at
these locations.
If you need a more precisely defined U-turn policy, consider adding a
global turn delay evaluator to a network cost attribute, or adjusting its
settings if one exists, and pay particular attention to the configuration of
reverse turns. Also, look at setting the CurbApproach property of your network
locations.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
time unit.
The tool performs the necessary time-unit conversion when the Break Units
value differs from the units of the cost attribute defined here. In other
words, the time units of the breaks and the network cost attribute don't need
to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute Units (optional)
The units of the network cost attribute specified by the Time Attribute
parameter. This is merely an informational parameter that cannot be changed
without directly editing the network dataset. It is also unnecessary to change
since the unit conversions between break value units and the cost attribute are
handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
distance unit.
The tool performs the necessary distance-unit conversion when the Break
Units value differs from the units of the cost attribute defined here. In other
words, the distance units of the breaks and the network cost attribute don't
need to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute Units
(optional)
The units of the network cost attribute specified by the Distance
Attribute parameter. This is merely an informational parameter that cannot be
changed without directly editing the network dataset. It is also unnecessary to
change since the unit conversions between break value units and the cost
attribute are handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Use Hierarchy in Analysis
(optional)
· Checked—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. This option is enabled only if the
input network dataset has a hierarchy attribute.
· Unchecked—Do not use the hierarchy attribute for the analysis. Not using a
hierarchy yields an exact route for the network dataset.
The parameter is disabled if a hierarchy attribute is not defined on the
network dataset used to perform the analysis.
You can use the Force Hierarchy Beyond Distance parameter to force the
solver to use hierarchy even if Use Hierarchy in Analysis is set to false.
This parameter is ignored unless Travel Mode is set to Custom. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
· USE_HIERARCHY— 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. This option is valid only if the
input network dataset has a hierarchy attribute.
· NO_HIERARCHY—Do not use the hierarchy attribute for the analysis. Not
using a hierarchy yields an exact route for the network dataset.
The parameter is not used if a hierarchy attribute is not defined on the
network dataset used to perform the analysis. In such cases, use "#"
as the parameter value.
You can use the Force_Hierarchy_Beyond_Distance parameter to force the
solve to use hierarchy even if Use_Hierarchy_in_Analysis is set to False.
This parameter is ignored unless Travel_Mode is set to CUSTOM. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
Restrictions (optional)
Indicates which network restriction attributes are respected during solve
time.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Attribute Parameter Values
(optional)
Specifies the parameter values for network attributes that have
parameters. The record set has two columns that work together to uniquely
identify parameters and another column that specifies the parameter value.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
The attribute parameter values record set has associated attributes. The
fields in the attribute table are listed below and described.
ObjectID:
The system-managed ID field.
AttributeName:
The name of the network attribute whose attribute parameter is set by the
table row.
ParameterName:
The name of the attribute parameter whose value is set by the table row.
(Object type parameters cannot be updated using this tool.)
ParameterValue:
The value you want for the attribute parameter. If a value is not
specified, the attribute parameter is set to null.
Polygon Simplification Tolerance
(optional)
Specify by how much you want to simplify the polygon geometry.
Simplification maintains critical points of a polygon to define its
essential shape and removes other points. The simplification distance you
specify is the maximum allowable offset from the original polygon from which
the simplified polygon can deviate. Simplifying a polygon reduces the number of
vertices and tends to reduce drawing times.
Maximum Snap Tolerance (optional)
The maximum snap tolerance is the furthest distance that Network Analyst
searches when locating or relocating a point onto the network. The search looks
for suitable edges or junctions and snaps the point to the nearest one. If a
suitable location isn't found within the maximum snap tolerance, the object is
marked as unlocated.
Exclude Restricted Portions of the
Network (optional)
· Checked—Facilities are only located on traversable portions of the
network. This prevents locating them on elements that can't be reached during
the solve process due to restrictions or barriers. Bear in mind that facilities
may be located farther from their intended location than if this option were
left unchecked.
· Unchecked—Facilities can be located on any of the elements of the network;
however, the facilities that are located on restricted elements cannot be used
during the solve process.
Feature Locator WHERE Clause
(optional)
An SQL expression used to select a subset of source features that limits
which network elements facilities can be located on. The syntax for this
parameter consists of two parts: the first is the source feature class name
(followed by a space), and the second is the SQL expression. To write an SQL
expression for two or more source feature classes, separate them with a
semicolon.
To ensure facilities are not located on limited-access highways, for
example, write an SQL expression like the following to exclude those source
features: "Streets" "FUNC_CLASS not in('1', '2')".
Note that barriers ignore the feature locator WHERE clause when loading.
Polygons for Multiple Facilities
(optional)
Choose how service area polygons are generated when multiple facilities
are present in the analysis.
· NO_MERGE—Creates individual polygons for each facility. The polygons can
overlap each other.
· NO_OVERLAP— 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— Creates and joins the polygons of different facilities that have
the same break value.
Polygon Overlap Type (optional)
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—Does not include the area of the 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.
· 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.
Detailed Polygons (optional)
Specifies whether to create detailed or generalized polygons.
· Checked—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.
· Unchecked—Creates generalized polygons, which are generated quickly and
are fairly accurate.
Polygon Trim Distance (optional)
Specifies the distance within which the service area polygons are trimmed.
This is useful when your data is very sparse and you don't want the service
area to cover large areas where there are no features.
No value or a value of 0 for this parameter specifies that the service
area polygons should not be trimmed. The parameter value is ignored when using
hierarchy.
Save Output Network Analysis Layer
(optional)
Choose whether the output includes a network analysis layer of the
results. In either case, a feature class with service area polygons is
returned. However, a server administrator may want to choose to output a
network analysis layer as well so the setup and results of the tool can be
debugged using the Network Analyst controls in the ArcGIS Desktop environment.
This can make the debugging process much easier.
In ArcGIS Desktop, the default output location for the network analysis
layer is in the scratch folder. You can determine the location of the scratch
folder by evaluating the value of the arcpy.env.scratchFolder geoprocessing
environment in the Python window. The output network analysis layer is stored
as an LYR file whose name starts with _ags_gpna and is followed by an
alphanumeric GUID.
Maximum Facilities (optional)
Limits how many facilities can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Number of Breaks
(optional)
Limits how many breaks can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Point
Barriers (optional)
Limits how many features can be affected by point barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Line
Barriers (optional)
Limits how many features can be affected by line barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by
Polygon Barriers (optional)
Limits how many features can be affected by polygon barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Time Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving time-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Distance Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving distance-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Force Hierarchy beyond Break Time
Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving time-based service areas.
Solving service areas for high break values while using the network's
hierarchy tends to incur much less processing than solving the same service
areas without using the hierarchy. This parameter helps you govern the amount
of processing that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
Force Hierarchy beyond Break
Distance Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving distance-based service areas.
Solving service areas for high break values while using the network's
hierarchy tends to incur much less processing than solving the same service
areas without using the hierarchy. This parameter helps you govern the amount
of processing that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
2.
Break Values قيم الراحة
Specifies the size and
number of service area polygons to generate for each facility. The units are
determined by the Break Units value.
يحدد حجم وعدد مضلعات منطقة الخدمة المراد إنشاؤها
لكل منشأة. يتم تحديد الوحدات حسب قيمة وحدات الفاصل.
عند تشغيل أداة إنشاء مناطق الخدمة ، يحدث تفاعل
جدير بالملاحظة بين المعلمات التالية: كسر القيم ، ووحدات الفاصل ، وإما سمة الوقت
أو سمة المسافة. تحدد قيم القطع ووحدات الاستراحة معًا إلى أي مدى أو إلى متى يجب
أن تمتد منطقة الخدمة حول المنشأة أو المرافق. تحدد كل من معلمات سمة الوقت وخاصية
المسافة سمة واحدة لتكلفة الشبكة. يتم استخدام سمة واحدة فقط من هاتين الخاصيتين
من سمات التكلفة ، ومع ذلك ، فإن السمة التي يختارها المحلل لاستخدامها تتوافق مع
قيمة وحدات الفاصل ؛ أي عندما تحدد قيمة وحدات فاصل مستندة إلى الوقت ، مثل
الثواني أو الدقائق ، تحل الأداة باستخدام سمة التكلفة المحددة في معلمة سمة
الوقت. عندما تحدد قيمة وحدات فاصل تعتمد على المسافة ، مثل الكيلومترات أو
الأميال ، فإنها تستخدم سمة التكلفة المحددة في معلمة سمة المسافة.
يمكن تعيين فواصل متعددة الأضلاع لإنشاء مناطق
خدمة متحدة المركز لكل منشأة. على سبيل المثال ، للعثور على مناطق خدمة 2 و 3 و 5
أميال لكل منشأة ، أدخل 2 3 5 ، وافصل القيم بمسافة. عيّن وحدات الفاصل إلى أميال
وتأكد من أنك قد اخترت سمة شبكة تعتمد على المسافة لمعلمة سمة المسافة.
Break Units
The units for the Break Values parameter.
· Meters
· Kilometers
· Feet
· Yards
· Miles
· Nautical Miles
· Seconds
· Minutes
· Hours
· Days
The Generate Service Areas tool chooses whether to use the network cost
attribute specified in the Time Attribute or Distance Attribute parameter
depending on whether the units you specify here are time or distance based.
The tool performs the necessary units conversion when the Break Units
value differs from the units of the corresponding time or distance cost
attribute.
Network Dataset
The network dataset on which the analysis will be performed. Network
datasets most often represent street networks but may represent other kinds of
transportation networks as well. The network dataset needs at least one
time-based and one distance-based cost attribute.
Service Areas
The output workspace and name of the output features. This workspace must
already exist. The default output workspace is in_memory.
Travel Mode (optional)
Choose the mode of transportation for the analysis. Custom is always a
choice. For other travel mode names to appear, they must be present in the
network dataset specified in the Network Dataset parameter.
A travel mode is defined on a network dataset and provides override values
for parameters that, together, model cars, trucks, pedestrians, or other modes
of travel. By choosing a travel mode here, you don't need to provide values for
the following parameters, which are overridden by values specified in the
network dataset:
· UTurn Policy
· Time Attribute
· Time Attribute Units
· Distance Attribute
· Distance Attribute Units
· Use Hierarchy in Analysis
· Restrictions
· Attribute Parameter Values
· Polygon Simplification Tolerance
· CUSTOM—Define a travel mode that fits your specific needs. When Custom is
chosen, the tool does not override the travel mode parameters listed above.
This is the default value.
Travel Direction (optional)
Choose whether the direction of travel used to generate the service area
polygons is toward or away from the facilities.
· TRAVEL_FROM—The service area is generated in the direction away from the
facilities.
· TRAVEL_TO—The service area is created in the direction toward the
facilities.
The direction of travel may change the shape of the polygons because
impedances on opposite sides of a street may differ, or one-way streets may
exist. 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 since the critical travel time for a
patient is traveling to the hospital.
Time of Day (optional)
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 travel away
from facilities.
· It represents the arrival time if Travel Direction is set to travel toward
facilities.
Your network dataset must include traffic data for this parameter to have
any effect.
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 5-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.
Time Zone for Time of Day (optional)
Specifies the time zone or zones of the Time of Day parameter.
· GEO_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 or zones they are 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.
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.
Overrides (optional)
Additional settings that can be used to influence the behavior of the
solver.
The value for this parameter is specified in JavaScript Object Notation
(JSON) using the form {"overrideSetting1" : "value1",
"overrideSetting2" : "value2"}. The override setting names
are always enclosed in double quotation marks. The values can be a number,
Boolean, or a string.
Overrides are advanced settings that should be used only with careful
analysis of the results obtained before and after applying the settings. A list
of supported override settings for each solver and their acceptable values can
be obtained by contacting Esri Technical Support.
Point Barriers (optional)
Specifies point barriers, which are split into two types: restriction and
added cost point barriers. They temporarily restrict traversal across or add
impedance to points on the network. The point barriers are defined by a feature
set, and the attribute values you specify for the point features determine
whether they are restriction or added cost barriers. The fields in the
attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or adds cost
when traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through the barrier. This is the
default value.
· Added Cost (2)—Traversing through the barrier increases the network cost
by the amount specified in the Additional_Time and Additional_Distance fields.
Use the value 0 for Restriction and 2 for Added Cost.
AdditionalCost:
AdditionalCost indicates how much impedance is added when a service area
passes through the barrier.
The unit for this field value is the same as the units specified for Break
Units.
Line Barriers (optional)
Specifies line barriers, which temporarily restrict traversal across them.
The line barriers are defined by a feature set. The fields in the attribute
table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
Polygon Barriers (optional)
Specifies polygon barriers, which are split into two types: restriction
and scaled cost polygon barriers. They temporarily restrict traversal or scale
impedance on the parts of the network they cover. The polygon barriers are
defined by a feature set, and the attribute values you specify for the polygon
features determine whether they are restriction or scaled cost barriers. The
fields in the attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or scales the
cost of traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through any part of the barrier. This
is the default value.
· Scaled Cost (1)—Scales the impedance of underlying edges by multiplying
them by the value of the ScaledCostFactor property. If edges are partially
covered by the barrier, the impedance is apportioned and multiplied.
Use the value 0 for Restriction and 1 for Scaled Cost.
ScaledCostFactor:
ScaledCostFactor indicates how much the impedance is multiplied by when a
service area passes through the barrier.
UTurn Policy (optional)
The U-Turn policy at junctions. Allowing U-turns implies the solver can
turn around at a junction and double back on the same street. Given that
junctions represent street intersections and dead ends, different vehicles may
be able to turn around at some junctions but not at others—it depends on
whether the junction represents an intersection or dead end. To accommodate
this, the U-turn policy parameter is implicitly specified by how many edges
connect to the junction, which is known as junction valency. The acceptable
values for this parameter are listed below; each is followed by a description
of its meaning in terms of junction valency.
· ALLOW_UTURNS—U-turns are permitted at junctions with any number of
connected edges. This is the default value.
· NO_UTURNS—U-turns are prohibited at all junctions, regardless of junction
valency. Note, however, that U-turns are still permitted at network locations
even when this setting is chosen; however, you can set the individual network
location's CurbApproach property to prohibit U-turns there as well.
· ALLOW_DEAD_ENDS_ONLY—U-turns are prohibited at all junctions, except those
that have only one adjacent edge (a dead end).
· ALLOW_DEAD_ENDS_AND_INTERSECTIONS_ONLY—U-turns are prohibited at junctions
where exactly two adjacent edges meet but are permitted at intersections
(junctions with three or more adjacent edges) and dead ends (junctions with
exactly one adjacent edge). Often, networks have extraneous junctions in the
middle of road segments. This option prevents vehicles from making U-turns at
these locations.
If you need a more precisely defined U-turn policy, consider adding a global
turn delay evaluator to a network cost attribute, or adjusting its settings if
one exists, and pay particular attention to the configuration of reverse turns.
Also, look at setting the CurbApproach property of your network locations.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
time unit.
The tool performs the necessary time-unit conversion when the Break Units
value differs from the units of the cost attribute defined here. In other
words, the time units of the breaks and the network cost attribute don't need
to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute Units (optional)
The units of the network cost attribute specified by the Time Attribute
parameter. This is merely an informational parameter that cannot be changed
without directly editing the network dataset. It is also unnecessary to change
since the unit conversions between break value units and the cost attribute are
handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
distance unit.
The tool performs the necessary distance-unit conversion when the Break
Units value differs from the units of the cost attribute defined here. In other
words, the distance units of the breaks and the network cost attribute don't
need to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute Units
(optional)
The units of the network cost attribute specified by the Distance
Attribute parameter. This is merely an informational parameter that cannot be
changed without directly editing the network dataset. It is also unnecessary to
change since the unit conversions between break value units and the cost
attribute are handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Use Hierarchy in Analysis
(optional)
· Checked—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. This option is enabled only if the
input network dataset has a hierarchy attribute.
· Unchecked—Do not use the hierarchy attribute for the analysis. Not using a
hierarchy yields an exact route for the network dataset.
The parameter is disabled if a hierarchy attribute is not defined on the
network dataset used to perform the analysis.
You can use the Force Hierarchy Beyond Distance parameter to force the
solver to use hierarchy even if Use Hierarchy in Analysis is set to false.
This parameter is ignored unless Travel Mode is set to Custom. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
· USE_HIERARCHY— 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. This option is valid only if the
input network dataset has a hierarchy attribute.
· NO_HIERARCHY—Do not use the hierarchy attribute for the analysis. Not
using a hierarchy yields an exact route for the network dataset.
The parameter is not used if a hierarchy attribute is not defined on the
network dataset used to perform the analysis. In such cases, use "#"
as the parameter value.
You can use the Force_Hierarchy_Beyond_Distance parameter to force the
solve to use hierarchy even if Use_Hierarchy_in_Analysis is set to False.
This parameter is ignored unless Travel_Mode is set to CUSTOM. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
Restrictions (optional)
Indicates which network restriction attributes are respected during solve
time.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Attribute Parameter Values
(optional)
Specifies the parameter values for network attributes that have
parameters. The record set has two columns that work together to uniquely
identify parameters and another column that specifies the parameter value.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
The attribute parameter values record set has associated attributes. The
fields in the attribute table are listed below and described.
ObjectID:
The system-managed ID field.
AttributeName:
The name of the network attribute whose attribute parameter is set by the
table row.
ParameterName:
The name of the attribute parameter whose value is set by the table row.
(Object type parameters cannot be updated using this tool.)
ParameterValue:
The value you want for the attribute parameter. If a value is not
specified, the attribute parameter is set to null.
Polygon Simplification Tolerance
(optional)
Specify by how much you want to simplify the polygon geometry.
Simplification maintains critical points of a polygon to define its
essential shape and removes other points. The simplification distance you
specify is the maximum allowable offset from the original polygon from which
the simplified polygon can deviate. Simplifying a polygon reduces the number of
vertices and tends to reduce drawing times.
Maximum Snap Tolerance (optional)
The maximum snap tolerance is the furthest distance that Network Analyst
searches when locating or relocating a point onto the network. The search looks
for suitable edges or junctions and snaps the point to the nearest one. If a
suitable location isn't found within the maximum snap tolerance, the object is
marked as unlocated.
Exclude Restricted Portions of the
Network (optional)
· Checked—Facilities are only located on traversable portions of the
network. This prevents locating them on elements that can't be reached during
the solve process due to restrictions or barriers. Bear in mind that facilities
may be located farther from their intended location than if this option were
left unchecked.
· Unchecked—Facilities can be located on any of the elements of the network;
however, the facilities that are located on restricted elements cannot be used
during the solve process.
Feature Locator WHERE Clause
(optional)
An SQL expression used to select a subset of source features that limits
which network elements facilities can be located on. The syntax for this
parameter consists of two parts: the first is the source feature class name
(followed by a space), and the second is the SQL expression. To write an SQL
expression for two or more source feature classes, separate them with a
semicolon.
To ensure facilities are not located on limited-access highways, for
example, write an SQL expression like the following to exclude those source
features: "Streets" "FUNC_CLASS not in('1', '2')".
Note that barriers ignore the feature locator WHERE clause when loading.
Polygons for Multiple Facilities
(optional)
Choose how service area polygons are generated when multiple facilities
are present in the analysis.
· NO_MERGE—Creates individual polygons for each facility. The polygons can
overlap each other.
· NO_OVERLAP— 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— Creates and joins the polygons of different facilities that have
the same break value.
Polygon Overlap Type (optional)
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—Does not include the area of the 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.
· 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.
Detailed Polygons (optional)
Specifies whether to create detailed or generalized polygons.
· Checked—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.
· Unchecked—Creates generalized polygons, which are generated quickly and
are fairly accurate.
Polygon Trim Distance (optional)
Specifies the distance within which the service area polygons are trimmed.
This is useful when your data is very sparse and you don't want the service
area to cover large areas where there are no features.
No value or a value of 0 for this parameter specifies that the service
area polygons should not be trimmed. The parameter value is ignored when using
hierarchy.
Save Output Network Analysis Layer
(optional)
Choose whether the output includes a network analysis layer of the
results. In either case, a feature class with service area polygons is
returned. However, a server administrator may want to choose to output a
network analysis layer as well so the setup and results of the tool can be
debugged using the Network Analyst controls in the ArcGIS Desktop environment.
This can make the debugging process much easier.
In ArcGIS Desktop, the default output location for the network analysis
layer is in the scratch folder. You can determine the location of the scratch
folder by evaluating the value of the arcpy.env.scratchFolder geoprocessing
environment in the Python window. The output network analysis layer is stored
as an LYR file whose name starts with _ags_gpna and is followed by an
alphanumeric GUID.
Maximum Facilities (optional)
Limits how many facilities can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Number of Breaks
(optional)
Limits how many breaks can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Point
Barriers (optional)
Limits how many features can be affected by point barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Line
Barriers (optional)
Limits how many features can be affected by line barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by
Polygon Barriers (optional)
Limits how many features can be affected by polygon barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Time Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving time-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Distance Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving distance-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Force Hierarchy beyond Break Time
Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving time-based service areas.
Solving service areas for high break values while using the network's
hierarchy tends to incur much less processing than solving the same service
areas without using the hierarchy. This parameter helps you govern the amount
of processing that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
Force Hierarchy beyond Break
Distance Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving distance-based service areas.
Solving service areas for high break values while using the network's
hierarchy tends to incur much less processing than solving the same service
areas without using the hierarchy. This parameter helps you govern the amount
of processing that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
3.
Break Units وحدات الراحة
The units for the Break
Values parameter.
وحدات المعلمة Break Values.
• أمتار
• كيلومترات
•قدم
• ساحات
•اميال
• أميال بحرية
• ثواني
•الدقائق
•ساعات
•أيام
تختار أداة إنشاء مناطق الخدمة ما إذا كنت ستستخدم
سمة تكلفة الشبكة المحددة في سمة الوقت أو سمة المسافة بناءً على ما إذا كانت
الوحدات التي تحددها هنا تعتمد على الوقت أو المسافة.
تقوم الأداة بتحويل الوحدات الضرورية عندما تختلف
قيمة وحدات الفاصل عن وحدات سمة تكلفة المسافة أو الوقت المقابلة.
Network Dataset
The network dataset on which the analysis will be performed. Network
datasets most often represent street networks but may represent other kinds of
transportation networks as well. The network dataset needs at least one
time-based and one distance-based cost attribute.
Service Areas
The output workspace and name of the output features. This workspace must
already exist. The default output workspace is in_memory.
Travel Mode (optional)
Choose the mode of transportation for the analysis. Custom is always a
choice. For other travel mode names to appear, they must be present in the
network dataset specified in the Network Dataset parameter.
A travel mode is defined on a network dataset and provides override values
for parameters that, together, model cars, trucks, pedestrians, or other modes
of travel. By choosing a travel mode here, you don't need to provide values for
the following parameters, which are overridden by values specified in the
network dataset:
· UTurn Policy
· Time Attribute
· Time Attribute Units
· Distance Attribute
· Distance Attribute Units
· Use Hierarchy in Analysis
· Restrictions
· Attribute Parameter Values
· Polygon Simplification Tolerance
· CUSTOM—Define a travel mode that fits your specific needs. When Custom is
chosen, the tool does not override the travel mode parameters listed above.
This is the default value.
Travel Direction (optional)
Choose whether the direction of travel used to generate the service area
polygons is toward or away from the facilities.
· TRAVEL_FROM—The service area is generated in the direction away from the
facilities.
· TRAVEL_TO—The service area is created in the direction toward the
facilities.
The direction of travel may change the shape of the polygons because
impedances on opposite sides of a street may differ, or one-way streets may
exist. 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 since the critical travel time for a
patient is traveling to the hospital.
Time of Day (optional)
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 travel away
from facilities.
· It represents the arrival time if Travel Direction is set to travel toward
facilities.
Your network dataset must include traffic data for this parameter to have
any effect.
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 5-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.
Time Zone for Time of Day
(optional)
Specifies the time zone or zones of the Time of Day parameter.
· GEO_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 or zones they are 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.
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.
Overrides (optional)
Additional settings that can be used to influence the behavior of the
solver.
The value for this parameter is specified in JavaScript Object Notation
(JSON) using the form {"overrideSetting1" : "value1",
"overrideSetting2" : "value2"}. The override setting names
are always enclosed in double quotation marks. The values can be a number,
Boolean, or a string.
Overrides are advanced settings that should be used only with careful
analysis of the results obtained before and after applying the settings. A list
of supported override settings for each solver and their acceptable values can
be obtained by contacting Esri Technical Support.
Point Barriers (optional)
Specifies point barriers, which are split into two types: restriction and
added cost point barriers. They temporarily restrict traversal across or add
impedance to points on the network. The point barriers are defined by a feature
set, and the attribute values you specify for the point features determine
whether they are restriction or added cost barriers. The fields in the
attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or adds cost
when traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through the barrier. This is the
default value.
· Added Cost (2)—Traversing through the barrier increases the network cost
by the amount specified in the Additional_Time and Additional_Distance fields.
Use the value 0 for Restriction and 2 for Added Cost.
AdditionalCost:
AdditionalCost indicates how much impedance is added when a service area
passes through the barrier.
The unit for this field value is the same as the units specified for Break
Units.
Line Barriers (optional)
Specifies line barriers, which temporarily restrict traversal across them.
The line barriers are defined by a feature set. The fields in the attribute
table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
Polygon Barriers (optional)
Specifies polygon barriers, which are split into two types: restriction
and scaled cost polygon barriers. They temporarily restrict traversal or scale
impedance on the parts of the network they cover. The polygon barriers are
defined by a feature set, and the attribute values you specify for the polygon
features determine whether they are restriction or scaled cost barriers. The
fields in the attribute table are listed and described below.
ObjectID:
The system-managed ID field.
Shape:
The geometry field indicating the geographic location of the network
analysis object.
Name:
The name of the barrier.
BarrierType:
Specifies whether the barrier restricts travel completely or scales the
cost of traveling through it. There are two options:
· Restriction (0)—Prohibits traversing through any part of the barrier. This
is the default value.
· Scaled Cost (1)—Scales the impedance of underlying edges by multiplying
them by the value of the ScaledCostFactor property. If edges are partially
covered by the barrier, the impedance is apportioned and multiplied.
Use the value 0 for Restriction and 1 for Scaled Cost.
ScaledCostFactor:
ScaledCostFactor indicates how much the impedance is multiplied by when a
service area passes through the barrier.
UTurn Policy (optional)
The U-Turn policy at junctions. Allowing U-turns implies the solver can
turn around at a junction and double back on the same street. Given that
junctions represent street intersections and dead ends, different vehicles may
be able to turn around at some junctions but not at others—it depends on
whether the junction represents an intersection or dead end. To accommodate
this, the U-turn policy parameter is implicitly specified by how many edges
connect to the junction, which is known as junction valency. The acceptable
values for this parameter are listed below; each is followed by a description
of its meaning in terms of junction valency.
· ALLOW_UTURNS—U-turns are permitted at junctions with any number of
connected edges. This is the default value.
· NO_UTURNS—U-turns are prohibited at all junctions, regardless of junction
valency. Note, however, that U-turns are still permitted at network locations
even when this setting is chosen; however, you can set the individual network
location's CurbApproach property to prohibit U-turns there as well.
· ALLOW_DEAD_ENDS_ONLY—U-turns are prohibited at all junctions, except those
that have only one adjacent edge (a dead end).
· ALLOW_DEAD_ENDS_AND_INTERSECTIONS_ONLY—U-turns are prohibited at junctions
where exactly two adjacent edges meet but are permitted at intersections
(junctions with three or more adjacent edges) and dead ends (junctions with
exactly one adjacent edge). Often, networks have extraneous junctions in the
middle of road segments. This option prevents vehicles from making U-turns at
these locations.
If you need a more precisely defined U-turn policy, consider adding a
global turn delay evaluator to a network cost attribute, or adjusting its
settings if one exists, and pay particular attention to the configuration of
reverse turns. Also, look at setting the CurbApproach property of your network
locations.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
time unit.
The tool performs the necessary time-unit conversion when the Break Units
value differs from the units of the cost attribute defined here. In other
words, the time units of the breaks and the network cost attribute don't need
to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Time Attribute Units (optional)
The units of the network cost attribute specified by the Time Attribute
parameter. This is merely an informational parameter that cannot be changed
without directly editing the network dataset. It is also unnecessary to change
since the unit conversions between break value units and the cost attribute are
handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute (optional)
Defines the network cost attribute to use when the Break Units value is a
distance unit.
The tool performs the necessary distance-unit conversion when the Break
Units value differs from the units of the cost attribute defined here. In other
words, the distance units of the breaks and the network cost attribute don't
need to be the same.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Distance Attribute Units
(optional)
The units of the network cost attribute specified by the Distance
Attribute parameter. This is merely an informational parameter that cannot be
changed without directly editing the network dataset. It is also unnecessary to
change since the unit conversions between break value units and the cost
attribute are handled for you.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Use Hierarchy in Analysis
(optional)
· Checked—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. This option is enabled only if the
input network dataset has a hierarchy attribute.
· Unchecked—Do not use the hierarchy attribute for the analysis. Not using a
hierarchy yields an exact route for the network dataset.
The parameter is disabled if a hierarchy attribute is not defined on the
network dataset used to perform the analysis.
You can use the Force Hierarchy Beyond Distance parameter to force the
solver to use hierarchy even if Use Hierarchy in Analysis is set to false.
This parameter is ignored unless Travel Mode is set to Custom. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
· USE_HIERARCHY— 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. This option is valid only if the
input network dataset has a hierarchy attribute.
· NO_HIERARCHY—Do not use the hierarchy attribute for the analysis. Not
using a hierarchy yields an exact route for the network dataset.
The parameter is not used if a hierarchy attribute is not defined on the
network dataset used to perform the analysis. In such cases, use "#"
as the parameter value.
You can use the Force_Hierarchy_Beyond_Distance parameter to force the
solve to use hierarchy even if Use_Hierarchy_in_Analysis is set to False.
This parameter is ignored unless Travel_Mode is set to CUSTOM. When
modeling a custom walking mode, it is recommended to turn off hierarchy since
the hierarchy is designed for motorized vehicles.
Restrictions (optional)
Indicates which network restriction attributes are respected during solve
time.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
Attribute Parameter Values
(optional)
Specifies the parameter values for network attributes that have
parameters. The record set has two columns that work together to uniquely
identify parameters and another column that specifies the parameter value.
The value of this parameter is overridden when Travel Mode (Travel_Mode in
Python) is set to any value other than custom.
The attribute parameter values record set has associated attributes. The
fields in the attribute table are listed below and described.
ObjectID:
The system-managed ID field.
AttributeName:
The name of the network attribute whose attribute parameter is set by the
table row.
ParameterName:
The name of the attribute parameter whose value is set by the table row.
(Object type parameters cannot be updated using this tool.)
ParameterValue:
The value you want for the attribute parameter. If a value is not
specified, the attribute parameter is set to null.
Polygon Simplification Tolerance
(optional)
Specify by how much you want to simplify the polygon geometry.
Simplification maintains critical points of a polygon to define its
essential shape and removes other points. The simplification distance you
specify is the maximum allowable offset from the original polygon from which
the simplified polygon can deviate. Simplifying a polygon reduces the number of
vertices and tends to reduce drawing times.
Maximum Snap Tolerance (optional)
The maximum snap tolerance is the furthest distance that Network Analyst
searches when locating or relocating a point onto the network. The search looks
for suitable edges or junctions and snaps the point to the nearest one. If a
suitable location isn't found within the maximum snap tolerance, the object is
marked as unlocated.
Exclude Restricted Portions of the
Network (optional)
· Checked—Facilities are only located on traversable portions of the
network. This prevents locating them on elements that can't be reached during
the solve process due to restrictions or barriers. Bear in mind that facilities
may be located farther from their intended location than if this option were
left unchecked.
· Unchecked—Facilities can be located on any of the elements of the network;
however, the facilities that are located on restricted elements cannot be used
during the solve process.
Feature Locator WHERE Clause
(optional)
An SQL expression used to select a subset of source features that limits
which network elements facilities can be located on. The syntax for this
parameter consists of two parts: the first is the source feature class name
(followed by a space), and the second is the SQL expression. To write an SQL
expression for two or more source feature classes, separate them with a
semicolon.
To ensure facilities are not located on limited-access highways, for
example, write an SQL expression like the following to exclude those source
features: "Streets" "FUNC_CLASS not in('1', '2')".
Note that barriers ignore the feature locator WHERE clause when loading.
Polygons for Multiple Facilities
(optional)
Choose how service area polygons are generated when multiple facilities
are present in the analysis.
· NO_MERGE—Creates individual polygons for each facility. The polygons can
overlap each other.
· NO_OVERLAP— 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— Creates and joins the polygons of different facilities that have
the same break value.
Polygon Overlap Type (optional)
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—Does not include the area of the 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.
· 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.
Detailed Polygons (optional)
Specifies whether to create detailed or generalized polygons.
· Checked—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.
· Unchecked—Creates generalized polygons, which are generated quickly and
are fairly accurate.
Polygon Trim Distance (optional)
Specifies the distance within which the service area polygons are trimmed.
This is useful when your data is very sparse and you don't want the service
area to cover large areas where there are no features.
No value or a value of 0 for this parameter specifies that the service
area polygons should not be trimmed. The parameter value is ignored when using
hierarchy.
Save Output Network Analysis Layer
(optional)
Choose whether the output includes a network analysis layer of the
results. In either case, a feature class with service area polygons is
returned. However, a server administrator may want to choose to output a
network analysis layer as well so the setup and results of the tool can be
debugged using the Network Analyst controls in the ArcGIS Desktop environment.
This can make the debugging process much easier.
In ArcGIS Desktop, the default output location for the network analysis
layer is in the scratch folder. You can determine the location of the scratch
folder by evaluating the value of the arcpy.env.scratchFolder geoprocessing
environment in the Python window. The output network analysis layer is stored
as an LYR file whose name starts with _ags_gpna and is followed by an
alphanumeric GUID.
Maximum Facilities (optional)
Limits how many facilities can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Number of Breaks
(optional)
Limits how many breaks can be added to the service area analysis.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Point
Barriers (optional)
Limits how many features can be affected by point barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by Line
Barriers (optional)
Limits how many features can be affected by line barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Features Affected by
Polygon Barriers (optional)
Limits how many features can be affected by polygon barriers.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Time Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving time-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Maximum Break Distance Value
(optional)
Limits how large the value of the Break Value parameter can be when
solving distance-based service areas.
This parameter helps you govern the amount of processing that occurs when
solving. For example, you could assign a low value to this parameter for a free
version of the service you are creating and use a higher value for a
paid-subscription version of the service.
A null value indicates there is no limit.
Force Hierarchy beyond Break Time
Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving time-based service areas.
Solving service areas for high break values while using the network's hierarchy
tends to incur much less processing than solving the same service areas without
using the hierarchy. This parameter helps you govern the amount of processing
that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
Force Hierarchy beyond Break
Distance Value (optional)
Specifies the break value after which the solver will force hierarchy even
if hierarchy was not enabled when solving distance-based service areas.
Solving service areas for high break values while using the network's
hierarchy tends to incur much less processing than solving the same service
areas without using the hierarchy. This parameter helps you govern the amount
of processing that occurs when solving.
A null value indicates that the hierarchy will never be enforced and the
value of the Use Hierarchy in Analysis parameter will always be honored. If the
input network dataset does not support hierarchy, specifying a value for this
parameter will result in an error. A null value should be used in this case.
4.
Network Dataset مجموعة بيانات
الشبكة
The network dataset on
which the analysis will be performed. Network datasets most often represent
street networks but may represent other kinds of transportation networks as
well. The network dataset needs at least one time-based and one distance-based
cost attribute.
مجموعة بيانات الشبكة التي سيتم إجراء التحليل
عليها. غالبًا ما تمثل مجموعات بيانات الشبكة شبكات الشوارع ولكنها قد تمثل أيضًا
أنواعًا أخرى من شبكات النقل. تحتاج مجموعة بيانات الشبكة إلى سمة تكلفة واحدة تستند
إلى الوقت وواحدة على الأقل تستند إلى المسافة.
5.
Service Areas مناطق الخدمة
The output workspace and
name of the output features. This workspace must already exist. The default
output workspace is in_memory.
مساحة عمل الإخراج واسم ميزات الإخراج. يجب أن تكون
مساحة العمل هذه موجودة بالفعل. مساحة عمل الإخراج الافتراضية هي in_memory.
6.
Travel Mode (optional) وضع السفر
(اختياري)
Choose the mode of
transportation for the analysis. Custom is always a choice. For other travel
mode names to appear, they must be present in the network dataset specified in
the Network Dataset parameter.
اختر وسيلة النقل للتحليل. العرف هو دائما اختيار.
لكي تظهر أسماء أوضاع السفر الأخرى ، يجب أن تكون موجودة في مجموعة بيانات الشبكة
المحددة في معلمة مجموعة بيانات الشبكة.
يتم تحديد وضع السفر في مجموعة بيانات الشبكة
ويوفر قيم تجاوز للمعلمات التي تعمل معًا على تشكيل السيارات أو الشاحنات أو
المشاة أو أوضاع السفر الأخرى. باختيار وضع السفر هنا ، لا تحتاج إلى توفير قيم
للمعلمات التالية ، والتي يتم تجاوزها بالقيم المحددة في مجموعة بيانات الشبكة:
• سياسة UTurn
• سمة الوقت
• وحدات سمة الوقت
• سمة المسافة
• وحدات سمات المسافة
• استخدام التسلسل الهرمي
في التحليل
•قيود
• قيم معلمة السمة
• التسامح التبسيط المضلع
• CUSTOM - حدد وضع السفر الذي يناسب احتياجاتك الخاصة. عند اختيار Custom ، لا تتجاوز الأداة معلمات وضع السفر المذكورة أعلاه. هذه هي القيمة الافتراضية.
12. Advanced Analysis التحليل المتقدم
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