GTFS2GMNS: A Jupyter Notebook repository from Volpe National Transportation Systems Center - Volpe National Transportation Systems Center

GTFS2GMNS

The open-source Python codes (GTFS2GMNS) is released to facilitate researchers and planners to construct the multi-modal transit networks easily from generic General Transit Feed Specification (GTFS) to the network modeling format in General Modeling Network Specification (GMNS). The converted physical and service networks in GMNS format are more convenient for network modeling tasks such as transit network routing, traffic flow assignment, simulation and service network optimization.

Your comments will be valuable for code review and improvement. Please feel free to add your comments to our Google document of GTFS2GMNS Users' Guide.

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

GTFS2GMNS can handle the transit data from several agencies. Users need to configure different sub-files in the same directory. Under the test/GTFS folder, a subfolder Pheonix with its owm GTFS data is set up.

Convert GTFS Data into GMNS Format

if __name__ == '__main__':
    global period_start_time
    global period_end_time
    input_gtfs_path = 'GTFS'
    output_gmns_path = '.'
    time_period_id = 1
    time_period = '1200_1300'
    period_start_time, period_end_time = _hhmm_to_minutes(time_period)

    gtfs2gmns(input_gtfs_path, output_gmns_path)

The input parameter input_gtfs_path is the path of GTFS data, and the parameter output_gmns_path is the path of output GMNS files. Users can customize the parameter time_period, such as 12:00 to 13:00.

The output files include node.csv and link.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.

VolpeUSDOT/GTFS2GMNS