Editing transport scenarios
Transport scenarios in Conveyal Analysis are made up of a series of modifications of various types. When all the modifications are strung together, they represent a new state of the transport system in a region. This page describes the available modification types; each type also has an individual page describing the specifics of how to use it.
After uploading a GTFS Bundle and creating a project, you will arrive at the screen below, where you can manage scenarios and modifications.
You can create scenarios by clicking the "Create" button to the right of "Scenarios" and entering a name. The buttons at the right of the list of scenarios allow renaming the scenarios and showing or hiding them on a map.
A transport scenario is made up of many modifications, each of which represents a single operation on the baseline transit network (for example adding a line, or adjusting the speed of an existing line). All modifications are listed in the left panel. Each modification has an eye icon next to it, which controls whether it is currently displayed on the map. Clicking on the title of a modification will open it and allow you to edit it. On the detail panel for each modification, you can choose the scenarios in which it will be active.
Scenarios can be exported as .json by clicking the download icon next to modifications, or in a printer-friendly format by clicking the printer icon.
Available modification types
Importing modifications from another scenario
Occasionally, you may want to copy all of the modifications from one project into another. This may be useful to make a copy of a project, or to combine modifications developed by different team members into a single project (for instance, one team member working on rail changes and another on bus changes). To do this, click the arrow icon to the right of the project name .
You can then choose the project from which to import modifications. Only projects which use the same GTFS bundle will be available. All modifications will be imported; when there are multiple scenarios, the scenarios in the project being imported will be mapped directly to the scenarios in the receiving project (i.e. modifications in the first scenario will remain in the first scenario in the new project).
Importing modifications from Shapefiles
In general, it is best to create all modifications directly in this editing tool as it allows full control over all aspects of transit network design. However, on occasion, it may be desirable to import modifications from a GIS shapefile. If you have a Shapefile containing lines, you can upload it to Conveyal Analysis and have it turned into a set of Add Trips modifications. You first need to zip the components of the shapefile, then you can select the "Import shapefile" button to the right of the scenario name.
Once you have entered the Import Shapefile view and selected a zipped Shapefile, you will see the following.
There are several fields that must be filled in. The name of each modification is set from an attribute in the Shapefile; the attribute used may be selected here. Additional, the speed (in km/h) and frequency (in minutes) should be attributes in the Shapefile. Finally, since Shapefiles only contain the route geometry and not the stop locations, stops will be created automatically. The stop spacing should be specified. The generated stop positions may be individually edited after import, for example to place a stop at a major transfer point.