GTFS2GMNS

The General Transit Feed Specification (GTFS) defines a common format for public transportation schedules and associated geographic information. It is used by thousands of public transport providers. As a data conversion tool, gtfs2gmns, can directly convert the GTFS data to node, link, and agent files in the GMNS format. In addition, this tool can merge the transit network into the road network which is obtained from Open Street Map via OSM2GMNS.

The python code is developed based on the C++ version in NeXTA data hub, which is supported by the FHWA research project titled: "the Effective Integration of Analysis, Modeling, and Simulation Tools, AMS Data Hub Concept of operations". With external link to https://www.fhwa.dot.gov/publications/research/operations/13036/004.cfm and https://github.com/asu-trans-ai-lab/nexta.

Installation

GTFS2GMNS has been published on PyPI, and can be installed using:

pip install gtfs2gmns

Getting Started

Download GTFS Data

On TransitFeed homepage, users can browse and download official GTFS feeds from around the world. Make sure that the following files are present, so that we can proceed.

• stop.txt
• route.txt
• trip.txt
• stop_times.txt
• agency.txt

Set the Directory

GTFS2GMNS can handle the transit data from several agencies. Users need to configure different sub-files in the same directory. There are two agencies in the Raleigh, GoRaleigh and NCSU Wolfline. So under the Raleigh folder, two subfolders gtfs1 and gtfs2 are set up, and each subfolder includes its own GTFS data.

Convert GTFS Data into GMNS Format

import gtfs2gmns as gg

path = 'Raleigh'
gmns_path = '.'
gg.converting(path,gmns_path)

The input parameter path is the path of GTFS data, and the parameter gmns_path is the path of output GMNS files.

The output files include node.csv, link.csv, trip.csv and route.csv.

Main Steps

Read GTFS data

Step 1.1: Read routes.txt

• route_id, route_long_name, route_short_name, route_url, route_type

Step 1.2: Read stop.txt

• stop_id, stop_lat, stop_lon, direction, location_type, position, stop_code, stop_name, zone_id

Step 1.3: Read trips.txt

• trip_id, route_id, service_id, block_id, direction_id, shape_id, trip_type
• and create the directed_route_id by combining route_id and direction_id

Step 1.4: Read stop_times.txt

• trip_id, stop_id, arrival_time, deaprture_time, stop_sequence

• create directed_route_stop_id by combining directed_route_id and stop_id through the trip_id

  Note: the function needs to skip this record if trip_id is not defined, and link the virtual stop id with corresponding physical stop id.

• fetch the geometry of the direction_route_stop_id

• return the arrival_time for every stop

Building service network

Step 2.1 Create physical nodes

• physical node is the original stop in standard GTFS

Step 2.2 Create directed route stop vertexes

• add route stop vertexes. the node_id of route stop nodes starts from 100001

  Note: the route stop vertex the programing create nearby the corresponding physical node, to make some offset.

• add entrance link from physical node to route stop node

• add exit link from route stop node to physical node. As they both connect to the physical nodes, the in-station transfer process can be also implemented

Step 2.3 Create physical arcs

• add physical links between each physical node pair of each trip

Step 2.4 Create service arcs

• add service links between each route stop pair of each trip

Visualization

You can visualize generated networks using NeXTA or QGIS.

Upcoming Features

• Output service and trace files.
• Set the time period and add vdf_fftt and vdf_freq fields in link files.