Step 2 - Location

The second step when building a query is to define the locational filter.  The locational filter is defined by delineating one or more Areas of Interest (AOI). Only those crashes whose location falls within an AOI are returned with the query. An AOI must be a closed boundary, therefore some graphics or features that are used (points and lines) will be required to be buffered to result in a boundary.

The image below shows the Location Form for Step 2.

Area of Interest Preference

Only CLEAR Administrators will have this option allowing them to specify a statewide query. All other users will automatically be required to specify/define at least one AOI.

Defining an Area of Interest

AOIs can be defined in one of several ways:

•Drawing a Graphic – Draw on the map using points, lines, or polygons

•Build Path – Build a path along a roadway (from/to locations)

•Select Feature – Select a feature from another reference layer

•Select Intersections – The 'Area of Influence' polygon for a selected intersection is used to define the AOI

•Import from Shapefile – Importing a polygon(s) from an Esri shapefile.

Each AOI that is added to the query is listed in the “Current Areas of Interest” grid at the top of the panel

At least one AOI must be defined during this process.

Drawing an Area of Interest

An AOI can be drawn on the map using points, lines, or polygons that can be added to the map or traced onto it; these shapes can be optionally buffered.

To define an AOI by drawing a graphic:

•Click the Draw tool to be used (Point, Line, Rectangle, Circle, Polygon)

•The draw tool is activated on the map. Draw the graphic on the map display.

•Click the Add To AOI button. The graphic is added to the AOI grid (at the top)

Buffer

•To generate a buffer around the graphic, enter the specified distance, select the desired distance unit (Feet, Miles) and click the Generate Buffer button

Note: For a point or line, the graphic must be buffered to result in a boundary. For all other graphics, generating a buffer is optional.

Resetting the Tool

•The drawing can be cleared and reset by clicking the RESET button at anytime during the operation (starts over)

Build Area of Interest from a Path

This option allows a user to build one or more paths along a route, by defining to/from locations.

To define an AOI by building a path:

•Click the Build Path button

•Define the origin and destination of the path by clicking two points on the map.

•The path is generated between the two points and is buffered by the default distance

•Optionally, click the Add Barrier button to add barriers along the path (to recalculate the path avoiding the barrier(s)

•Click the Add To AOI button. The buffered path is added to the AOI grid at the top of the panel.

Buffer

•The buffer distance for the path can be changed by entering a new distance and units prior to building a path

Resetting the Tool

•The path can be cleared and reset by clicking the RESET button at anytime during the operation (starts over)

Select Feature

A user may be interested in using a feature from an existing layer to define the AOI. Different layers require different selection details.

The layers from which a feature can be selected are:

•County

•Municipality

•Route

•Street

•Intersecting Street

•Ramp

•DOT Region

•MPO

To define an AOI by selecting features:

•Select the feature type from the picklist. Features to be selected include:

•Each dialog is slightly different. Most have an option of “Select on Map” or a picklist

•To select on map, click the button then click on the desired feature in the map display

•The selected feature can be buffered by clicking the Generate Buffer button

•Click the Add To AOI button. The feature is added to the AOI grid at the top of the panel.

Note: For a point or line feature, the feature must be buffered to result in a boundary. For polygon features, generating a buffer is optional.

Selecting Intersections

A user can select one or more intersections from the master intersection dataset using this option. The 'Area of Influence' polygon for each intersection is used to define the AOI in this case. One or more intersections may be selected.

To select intersection, there are three options:

•Select by 'Master Intersection ID'

•Select on the Map

•Select by Intersection Attributes

To define an AOI by selecting an intersection:

•For a single intersection search:

•Click the Select on Map button and click on the intersection within the map, or,

•Enter the master intersection id and click the Find button.

•For attribute search:

•Enter the attributes of the desired intersection(s) and click Find

•The Area of Influence polygon(s) for the selected intersection(s) are displayed and the query results grid displays the intersection on the Intersection Search Results tab

•Within the results grid, check the box for the intersection(s) to be added as an AOI

•Click the Add To AOI button within the panel. The intersection area of influence is added to the AOI grid at the top of the panel.

Note: When searching by attribute the “Single AOI” checkbox will define if multiple intersections will be added as a single or multiple AOIs

More specific instructions are as follows:

To select by 'Master Intersection ID'

•Enter the correctly-formatted ID and select the 'Find' button, which will become active and selectable after entering the ID in the textbox shown below.

•A result will be returned to the 'Intersection Search Results'. Select the row by selecting the checkbox for that row on the far-left of the mentioned grid. At that point, the 'Add to AOI' button is selectable, select it to add the selected rows to the AOI.

•The 'Current Areas of Interest (AOI)' grid at the top of the Step 2 - Location form will be populated with the AOI derived from that intersection's area of influence.

To select from the Map

•Click the 'Select on Map' button and select an intersection on the map, navigating as necessary using the map tools.

•Any selected intersection(s) will appear on the 'Intersection Search Results'. Select the row(s) by selecting the checkbox for that row on the far-left of the mentioned grid. At that point, the 'Add to AOI' button is selectable, select it to add the selected rows to the AOI.

•The 'Current Areas of Interest (AOI)' grid at the top of the Step 2 - Location form will be populated with the AOI derived from that intersection's area of influence.

To select by Intersection Attributes

•A user should select sufficient Intersection Attributes to identify the relevant intersections. If more than 100 intersections can be returned then the user will be notified of this issue, and attributes must be added to limit the results to less than 100 intersections.Intersection Attributes include the following:

oCounty

oMunicipality

oOn Street

oCross Street

oIntersection Type

oNumber of Legs

oGeometry

oCrosswalk

oTraffic Control

oSignal Type

oPedestrian Signal Type

oLighting

oLeft Turn

oRight Turn Channelization

•Any selected intersection(s) will appear on the 'Intersection Search Results'. Select the row(s) by selecting the checkbox for that row on the far-left of the mentioned grid. At that point, the 'Add to AOI' button is selectable, select it to add the selected rows to the AOI. Before adding to the AOI, the 'Single AOI' checkbox can be unchecked to add each intersection selected as a separate AOI - otherwise they are added as a single AOI.

•The 'Current Areas of Interest (AOI)' grid at the top of the Step 2 - Location form will be populated with the AOI derived from that intersection's area of influence.

Import  from Shapefile

Areas of Interest (AOIs) can be imported from a shapefile. The shapefile must be ZIPped (.zip) and only contain polygon features.

To define an AOI by importing a shapefile:

•Click the Import... button

•Select the ZIP file containing the compressed polygon shapefile

•Polygons are then displayed on the map display and automatically added to the AOI grid

Note: If the shapefile contains multiple polygons, they are added as a single AOI. If multiple AOIs are desired, each polygon should be stored as a separate shapefile.

Area of Interest Grid

The AOI Grid lists all areas of interest for the current query. There are a number of functions available to manage the AOIs including:

•Renaming AOIs (click on the name to edit)

•Management Tools (individual AOI)

•Flash - Flashes the specified AOI boundary on the map display

•Zoom To - Zooms the map to the extent of the specified AOI

•Edit (Graphic only) - Allows the user to edit the AOI polygon/boundary

•Export to shapefile - Exports the specified AOI to a shapefile

•Delete - Deletes the specified AOI

•Group Management

•Remove All - Removes all AOIs from the grid

•Export All (Shapefile) - Exports all AOI polygons to a single shapefile

•Zoom to All - Zooms the map to the extent of all AOIs