Drive zone wizard

The Drive Zone Wizard provides a quick way to group records by their drive time, drive distance, straight line distance, or walking time from a specified point.

You can use this wizard in two different ways to create a virtual variable:

• Using a single geographic variable - for example Postal Area, Postal District or Postal Sector - to create the zones

  • In this case, the output of the wizard is a selector type virtual variable that combines together the categories - for example postal sectors - and creates zones that fall within your defined times or distances.
  • In the System explorer, the virtual variable will be nested under the variable on which it depends.

• Using latitude and longitude variable information to create the zones

  • FastStats creates expressions to accurately define each zone and then select only those who fall within the resulting drive zone shapes.

  • In this case, the output of the wizard is either

    • a selector type virtual variable for each individual centrepoint

      or

    • when using a file that contains multiple centre points, you have a further option to create a single, multi-response (flag array) variable for all points.

  • In the System explorer, you select the folder in which the virtual variable should sit.

In systems with latitude and longitude variables, use of the Bing API isochrone allows for fast and accurate processing of records, and the option to carry out walking time analysis is also available.

To get started:

• On the Wizard tab click on the Drive Zone link to start the wizard.

Settings¶

This is where you define the map settings to use when calculating the drive time, drive distance, or straight line - 'as the crow flies' - distance.

The World Region selects the map to use.

The Distance can be specified as Miles or Kilometres.

The Preferred Route can be set to calculate in terms of quickest time or shortest distance.

Centre point¶

You must specify the point(s) from which the drive zones should radiate.

This can be a single centre point:

If you have multiple centre points, they can be entered into a text file and dragged onto the input file drop-box:

Geo variable type¶

Once a centre point has been specified, you must select how to create the zones. Either:

• use a single geographic variable, such as Postcode, Postal Sector, Postal District or Postal Area

  • These variables have codes that will be used to plot the points from the centre point. Note, however, that when matching to a geographic variable in this way, any intersection will then include the whole of an area, regardless of where a point actually lies.

Alternatively:

• if available within your system - you can more accurately create zones using longitude and latitude variables

  • These variables are ordinarily defined in your system design to have a geo-format property called latitude or longitude

  

Select Use Geographic variables to go to Geographic Match

Select Use Latitude and Longitude variables to go to Select Latitude/Longitude

Geographic match¶

Drag and drop your geographic variable onto the drop-box here.

You can also specify the country in which the variable matches.

Lat long match¶

If your system contains one latitude and one longitude variable, these will auto-populate into the drop-boxes at this step.

When more than one option is available, you must select, drag and drop the variables across. Alternatively:

In Map wizards, where you need to specify latitude and longitude variables, you can right click and access a menu option that allows you to select and add variables which are marked with the relevant GeoFormat property:

Selecting the checkbox allows you to use the resulting virtual variable with the FastStats Map tool to create thematic maps of drive zones around a specified location. For more on creating thematic maps see Shaded Map.

When using the Drive Zone wizard with a file that contains multiple centre points, as well as the default option to create a selector type virtual variable for each point, you can also create a single multi-response (flag array) type variable for all points:

Time or distance¶

On this step of the wizard, you can choose how to create your zones, grouping by drive time, drive distance, distance as the crow flies or walking time.

Zones¶

Once you have defined any centre point(s) and selected a method for creating the zones, you must then specify and provide a description for each zone.

Each required zone must be entered in the table on this step of the wizard. The "Maximum Value" of each zone will either be the maximum drive time or the maximum drive or straight line distance from the centre point.

You can enter the drive time in seconds or minutes, and specify drive distance in miles or part-miles.

A Description is also required to be used for each group.

Records that don't fit one of the specified zones, either because they have an unclassified value for the geographic variable specified, or because they fall outside the biggest maximum value, will be grouped together. The default description of this unmatched group is "Unclassifed" but you can amend this using the text box at the bottom of the wizard window.

Your earlier choices, and the way in which FastStats generates the virtual variable, will now determine your next step.

• If you have used a geographic variable, such as Postal Area, you will proceed directly to the Notes step. This is because the virtual variable is of the combine categories type and will automatically be nested below the variable on which it depends.

• When using latitude and longitude variables, the virtual variable is of the create and update type and you will first move to the Folders step to decide where, within your System explorer window, you wish the new virtual variable to be positioned.

Folders¶

Choose the folder that the new variable should be created in.

By default, the new variable is placed into the Others folder, but you can highlight an existing folder or, if necessary, create a new folder to hold your virtual variable.

Notes¶

You can choose to add notes to your variable.

These can be viewed later by right-clicking on the variable once it is in the System explorer window.

Update variable¶

This step of the wizard allows you to define what the virtual variable will be called.

Enter the name into the Description box or, to overwrite an existing virtual variable, drag that variable onto the Drop the variable to overwrite here drop box.

When you have used a text file of multiple centre points to create a selector variable for each point, you will see a red Note prompt to use [centrepoint] as part of the variable description that is generated. By adding [centrepoint] - for example at the end of the description - the geographical location will be appended.

If you are working on an Enterprise version of FastStats, you can select the Modify Security Attributes box to access and modify the Security options for your virtual variable.

To provide new functionality for geographic mapping functions, billable Bing transactions apply. Each licensed user is credited with 6,600 transactions per year, sufficient for most normal use. For example, an initial calculation using a Drive Zone wizard request for 10 centre points each with 5 zones would result in 50 billable transactions. Subsequent data refreshes would be free.

Transactions over and above the allocated 6,600 per year are supplied at 1.5 pence each. To protect against unintentional spend on billable Bing transactions, warning messages and maximum volume checks are displayed.

Confirm Bing transactions¶

You must acknowledge and confirm the number of Bing transactions required to create and/or update the virtual variable(s).

Geographic variable¶

Here, the number of API requests will often be the number of zones, or the cardinality of the geographic variable used. If a maximum drive time is specified, this maximum is applied and only the locations reachable in that time are counted. If multiple centre points are defined, each one is calculated separately to give the total number of transactions.

Latitude and longitude variables¶

Once you have chosen your variable description, clicking Finish will open a dialog that confirms the number of Bing API requests needed to create the variable(s).

The example below is based on four UK postcodes defined as centre points, with 16 zones per point resulting from setting a 0-80 minutes drive time at a 5 minute accuracy:

Too many bing transactions warning¶

If you try to proceed when your permitted maximum is exceeded, you will see the following message and should contact the relevant person within your organisation:

Security¶

This is an optional step available on the Enterprise version of the software.

Use the tick boxes to set the security settings you wish to apply to this variable.

Finish¶

Once you have named your new variable (and defined any security settings for it), the final step is to create the virtual variable. You can see the matching process in action when you click Next from either the Update Variable or Security steps:

You are then taken to final step of the wizard where you can see that the processing has completed.

Click Finish to close the wizard.

Example 1¶

Postal Area has been used as the geographic variable to create drive times between 0 and 90 minutes from the Apteco offices in Warwick. The new variable is nested under the Postal Area variable in the Households folder of this System explorer:

This variable can now be used to make selections:

In the above example, use of a geographic variable (Postal Area) creates a combine categories type of virtual variable and you can click on the + symbols next to a category to see the postal areas falling into each. For example, you can see those falling into the 0 to 30 minute drive time include Birmingham, Coventry and Leicester:

Perhaps more surprisingly, areas including Oxford and Gloucester are also shown to fall within a 0 to 30 minute drive time. This is because those postal areas have been intersected by the 30 minute drive time - albeit only just - but, as a result, all households within those postal area map shapes are then included.

Example 2¶

Whilst using smaller shape files - for example Postal Sector instead of Area - will improve accuracy when using a geographic variable, in systems with latitude and longitude variables, use of the Bing API isochrone allows for the faster and most accurate processing of records.

The map below displays the 0-60 minute walking time from the Apteco office in Warwick. Using latitude and longitude allows for greater precision.

Example 3¶

The selection below demonstrates the result of creating a single, multi-response (flag array) type virtual variable for all points:

By also selecting the check-box to create thematic mapping zones on the Lat Long Match step of the wizard, it is quick and easy to generate drive zone map visualisations of multiple centre points in a single map layer using the Map tool.

The example below displays the number of people within a 90-minute drivetime of three UK safari parks:

Click Finish to close the wizard.