GTFS feeds enable transit or public transport agencies to publish their data, and developers to write applications that use this data in an interoperable way. Dimitris Triantafyllos explores how to import this GTFS data into an Aimsun Next model.
What is GTFS?
The General Transit Feed Specification (GTFS), also known as GTFS static or static transit (to differentiate it from the GTFS realtime extension), defines a common format for public transportation (PT) schedules and associated geographic information.
GTFS feeds enable PT agencies to publish their data and developers to write applications that use this data in an interoperable way. A GTFS feed is composed of a series of text files collected in a ZIP file. Each file models a particular aspect of PT information: stops, routes, trips, and other schedule data. The details of each file are defined in the GTFS reference document.
Where can I find public GTFS feeds?
A list of transit agencies who provide GTFS public feeds is available on the GoogleTransitDataFeed project site.
How can I use the GTFS importer in Aimsun Next?
Requirements
After downloading the GTFS folder (see link above), verify that it includes the required files: agency.txt, stops.txt, routes.txt, trips.txt, and stop_times.txt.
The following files are optional and, if available, can be used to improve the accuracy of the GTFS importer: calendar.txt, calendar_dates.txt, fare_attributes.txt, fare_rules.txt, shapes.txt, frequencies.txt, transfers.txt, and feed_info.txt.
Recommended workflow:
- Import the transit stops and fix any stops that are placed in the wrong locations.
- Import the transit lines, with the stops correctly placed, and verify that the lines have been imported correctly.
- Import the timetables of these lines and check that they have been imported correctly.
The GTFS importer creates the transit stops, lines, and timetables within the boundaries of the sub-network and/or for the geometry related to a specific scenario.
A. To import the transit stops:
- Select File > Import > GTFS Data to open the GTFS Importer dialog:
- In the field Directory, select the path to the GTFS folder.
- In the Inputs group box, tick the option Stops. This means that only transit stops are imported.
- In the field Subnetwork, select the GTFS subnetwork you want to work with. If you leave this choice as None, the importer will use the whole network.
- In the field Scenario, select Dynamic Scenario. The GTFS importer will create the stops according to the geometry configuration of this scenario.
- Leave the Search Distance options with their default values.