Isochrones

Overview

This macro can be used to create travel time polygons showing the areas that are reachable within a chosen travel time, by any method of transport.

Inputs

This macro runs off a single input data file.

The input data must include two fields, one specifying the latitude and one specifying the longitude (of the origin point to calculate the isochrone from).

1. Credentials

‘Application ID’ and ‘Application Key’ must be filled in with your API key details.

If you don’t already have an API key, you can get a trial key here.

2. Configuration

Select Longitude Field

  • Select the field from the input data that specifies the longitude of the origin point

Select Latitude Field

  • Select the field from the input data that specifies the latitude of the origin point

Search Method

  • ‘Arriving By’ - shows the area representing journeys that arrive at the origin point by the chosen time
  • ‘Departing At’ - shows the area representing journeys that depart from the origin point at the chosen time

Isochrone Time

  • Set Specific Time - the maximum travel time to be used to calculate the isochrone (to generate multiple isochrones for different travel times, enter multiple values separated by a comma)
  • Set Time from Field - use a field in the input data to determine the maximum travel time for calculating the isochrone

3. Basic

Transport Method

  • Set Specific Transport Method - chose the method of transport (selecting multiple options will create multiple isochrones)
  • Select Transport Method from Field - use a field in the input data to select the transport method

Search Date Time

  • Set Specific Date Time - set the date and time to be used as the ‘Arriving By’ or ‘Departing At’ time
  • Set Date Time from Field - use a field in the input data to select the date and time for ‘Arriving By’ or ‘Departing At’

Time zone

  • The desired time zone to be used can be selected from the ‘Select Time Zone’ dropdown

4. Advanced

The advanced parameters can be used to configure the most granular features of the request.

These are pre-populated with realistic estimates, and so in the majority of cases will not require updating.

  • Time needed to board public transport vehicle - the time (in mins) taken to board a train/bus/coach etc. Cannot be greater than the Isochrone Time value.

  • Maximum walking time - the maximum time (in mins) allowed for walking from the origin to a station/stop, and from a station/stop to the destination. Cannot be greater than the Isochrone Time value.

  • Maximum driving time to station - the maximum time (in mins) allowed for driving from the origin to the station (when using ‘Driving and Train’ transport type). Cannot be greater than the Isochrone Time value.

  • Maximum cycling time to station - the maximum time (in mins) allowed for cycling from the origin to the station (when using ‘Cycling and Public Transport’ transport type). Cannot be greater than the Isochrone Time value.

  • Time required to park a car or bike - the time (in mins) taken to park a car or bike. Cannot be greater than the Isochrone Time value.

  • Time required to board a ferry - the time (in mins) taken to board a ferry. Cannot be greater than the Isochrone Time value.

Outputs

This macro returns 2 outputs:

  • ’S’ output - rows that have successfully generated an isochrone
  • ‘F’ output - rows that have not successfully generated an isochrone, along with the HTTP status, error code, description of the error, and link to where the error codes are documented

When multiple journey times and/or multiple transport methods are selected, each combination of parameters will return a separate isochrone. For example, when using one starting location, two journey times, and three transport methods, a total of six isochrones will be returned.

Successful Output Information

For successful results, the macro will append a number of fields onto the end of the input data:

  • Isochrone - the calculated polygon (NB - use a Browse tool to view on a map)
  • Query details - *these fields record the specific parameters used for each query so that they can be easily identified. *

Tip - selecting a Record will highlight the corresponding Isochrone on the map, and vice versa

Creating Unions and Intersections

Isochrones can easily be combined with the Summarize tool to create intersections (area within ALL isochrones) and unions (area within ANY isochrone).

  • Intersection – select the Isochrone spatial object field and use the ‘Create Intersection’ action under the ‘Spatial’ actions
  • Union – select the Isochrone spatial object field and use the ‘Combine’ action under the ‘Spatial’ actions

Documentation

Documentation for the API endpoint used by this macro can be found here:

https://docs.traveltime.com/api/reference/time-map