Isochrones in ArcGIS Pro

In this guest post written by Chris Hutchinson we take a look at TravelTime, an alternative to Network Analyst extension in ArcGIS Pro.

Making isochrones in ArcGIS has always been possible using the Network Analyst extension. This allows users to see where's reachable within a drive time area and it can be used to map catchment areas and visualise how far it's possible to travel within a time limit.

This extension cannot be used for public transport travel time analytics. However using the TravelTime add-in for ArcGIS this is possible. The add-in is accessible via a free 2 week trial or an annual license for £3,000.

Example of how Network Analyst can be used within ArcGIS to make drive time areas

This walkthrough will describe how to make isochrones show the area that is reachable from a starting point in a given amount of time using public transport. These can replace distance radius areas to provide much more relevant catchment or trade areas.

Examples of using isochrones include:

Calculating the number of customers within 45 minutes of different retail stores

Assessing which office would mean the most employees having a 1 hour commute or less

Determining the available workforce reachable from a number of potential real estate sites

The TravelTime add-in for ArcGIS Pro is an easy to install, self-contained add-in that brings powerful new capabilities to Pro users. It contains a similar set of tools to the Network Analyst tools in Pro (Isochrones, Origin Destination Matrices, and Routing) but is crucially different in a few areas:

Includes public transport and cycling modes, as well as driving and walking

Does not consume any ArcGIS Credits

Can process large data sets significantly faster

In this tutorial, we will demonstrate a couple of the ways that the TravelTime add-in can be used to create isochrones. We will also explore some of the ways in which these isochrones can then be combined for further analysis.

Creating Isochrones

Option 1 -- Using the Toolbar

The easiest way to create isochrones using the TravelTime add-in is through the toolbar.

The Quick Time Map tool has a few simple parameters to configure.

To run the tool, we simply click on the desired Origin on the map. The 15, 30, and 45 minute isochrones are created in one go, and we can then update the symbology to more easily identify them.

Instead of clicking on the map, the Quick Time Map tool can also be run by entering an address or a lat-long into the config box.

Option 2 -- Using the Toolbox and a Points Layer

The Quick Time Map example above is great for creating one or two isochrones at a time, but for creating lots at once then the best option is to use the TravelTime toolbox in the Catalog Pane.

In the example below we have a point layer of sites across the UK that we are interested in.

To create an isochrone around each site at once, we can use the Time Map Simple tool.

We configure the tool to create 60 minute isochrones, arriving at each site at 9am.

After hitting Run, within seconds we have the isochrones added as a new layer to the map.

Zooming in on one particular site, it's clear how different the public transport catchment area is to a simple radius-based analysis.

Advanced isochrone use cases

1 - Unions

Unions are great for visualisation your market service area. As an example, you can calculate where's reachable within a 30-minute travel time from each of your retail locations to see which communities you currently service. Combining these will create a visual of where is already serviced and where new locations could be placed to fill the gaps.

Created using the Time Map Simple tool, with Result Aggregation set as UNION

2 - Intersect

This is useful when trying to identify high areas of competition or which locations have great local service coverage. The checked shaded area on the screenshot below highlights which locations are easily accessible by all start points.

Overlapping area created using the Time Map Simple tool, with Result Aggregation set as INTERSECTION

3 - Heatmap

Creating several rings around the start location gives a heat map so that it's possible to see a sliding scale of where's reachable within a range of travel times.

Created using the Time Map Simple Batch tool