Walk Distance Maps & AnalysisUsing Network Analyst

by Christy Jacobsby Christy Jacobs

What’s a walk distance map?

WalkDistance Polygons

School

A A walk distance mapwalk distance map is a map of one or more individual is a map of one or more individual polygons around each school of interest. Each polygon is polygons around each school of interest. Each polygon is

created around a school and designates an area of a created around a school and designates an area of a certain distance on the street network. A lot of times these certain distance on the street network. A lot of times these polygons are used to analyze and count students that are polygons are used to analyze and count students that are

within the designated walking distance of each school.within the designated walking distance of each school.

Introducing Network Analyst

• Network Analyst allows you to create and manage network data sets and generate routing systems

• Use for network-based spatial analysis

- location analysis

- spatial interaction modeling

Using Network Analyst – Analyses Types

• Finding the best route- the shortest or most scenic route from set location to set location

• Finding the closest facility

• Finding a service area - finding the service areas around facilities

based on a cost attribute (length/distance, time)

• Creating an OD (Origin-Destination) Cost Matrix - used for routing of multiple originations to one destination and manages

individual impedances for each origination

• What’s a Service Area in Network Analyst?- the area around a facility, based on a

network, that the facility can service depending on

the cost attribute

Understanding Service Areas

In this map in Network Analyst terms :

The cost attribute is miles, schools are the facilities and the service area is the 1- mile area shown as a polygon on the street network in the area around the school

Service Area Polygon

Facility Point

In this map:Each blue area

displays the area within 1 mile

of each school, based on the

street network around the

school

Creating Network Analyst Datasets

Before beginning to work with Network Analyst to create network routing and areas, you have to create a network

dataset to work with:

Creating Network Analyst Datasets

In ArcCatalog, right click on the dataset that contains the data to be used in the Network dataset

New NetworkAnalyst Wizard

Go to “New”, then click on “Network Dataset”

Creating Network Analyst Datasets

Name theNetworkDataset

Choose the

participating data

Connectivitysettings

Creating Network Analyst Datasets

Modeling

Turns

Elevation Data Settings

Creating Network Analyst Datasets

Choose Cost AttributesCan UseShape Length

as aCost

Attribute

Creating Network Analyst Datasets

Set DrivingDirections, if desired

Summary

Click on “Finish” and then when prompted to

“Build” the network dataset,

select “Yes”

Introducing the Network Analyst Extension toolbar

Check onNetworkAnalystToolbar

Note: Be sure the extension is turned on in Tools – Extensions before bringing in

the Network Analyst toolbar

Navigating the Network Analyst toolbar

Choose Network type

Create NetworkLocation Tool

Select/Move NetworkLocation Tool

Active NetworkDataset

NetworkIdentify

Tool

SolveButton

BuildButton

Show/HideNetworkAnalystWindow

Network Analyst in ArcMap

NetworkAnalystWindow

NetworkAnalystLayers

• What’s a Service Area in Network Analyst?- the area around a facility, based on a

network, that the facility can service depending on

the cost attribute

Review of Service Area Features

In this map in Network Analyst terms :

The cost attribute is miles, schools are the facilities and the service area is the 1- mile area shown as a polygon on the street network in the area around the school

Service Area Polygon

Facility Point

In this map:Each blue area

displays the area within 1 mile

of each school, based on the

street network around the

school

I have walk distance polygons of 1 mile.I have walk distance polygons of 1 mile.

Now what??Now what??

Using Service Areas to Analyze Walk Distance and Student Location

Bring in yourBring in your

students file students file and select, and select, query and query and

analyze the analyze the students that students that are within the are within the walk distances walk distances

polygons or polygons or outsideoutside

Use “Select by Location” to

isolate students that reside within the polygons

Using Network Analyst

Let’s use Network Analyst to create a service area that displays a walk/drive distance of 1 mile

around school locations, then select students that are within those service area polygons