GTFS2GMNS

The open-source Python package, 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.

Input and Output

Input: Static GTFS data Output: Transit service network with GMNS format (node.csv and link.csv). Users can customize:

1. the path of input GTFS data and output GMNS files
2. time_period, such as 12:00 to 13:00.
3. date_period, such as 10/29/2024.

Getting Started

Step 1: 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 BART with its own GTFS data is set up.

Step 2: Install gtfs2gmns package

Before you install gtfs2gmns, please ensure you have installed Python 3.9 or higher on your system.

Please open your terminal (or command prompt) and run the following command:

pip install gtfs2gmns

This command will download and install gtfs2gmns along with any necessary dependencies.

Optional: Installing in a virtual environment

If you prefer to keep your Python environment isolated for specific projects, you can install gtfs2gmns in a virtual environment.

1. Create a virtual environment (replace env_name with your preferred name):

python -m venv env_name

2. Activate the virtual environment: On Windows:

.\env_name\Scripts\activate

On macOS/Linux:

source env_name/bin/activate

4. Install gtfs2gmns within the virtual environment:

pip install gtfs2gmns

6. To exit the virtual environment, simply type: deactivate

Step 3: Run test code

from gtfs2gmns import GTFS2GMNS

# Input and Output Directories
gtfs_input_dir = './GTFS'
gtfs_output_dir = './GMNS'

# Time and Date Configuration
time_period = "07:00:00_08:00:00"
date_period = []  # Assuming you might add specific dates to this list for testing

# Create an instance of the GTFS2GMNS class
gtfs2gmns_converter = GTFS2GMNS(
    gtfs_input_dir=gtfs_input_dir,
    gtfs_output_dir=gtfs_output_dir,
    time_period=time_period,
    date_period=date_period
)

# Load GTFS data
print("Loading GTFS data...")
gtfs2gmns_converter.load_gtfs()

# Generate GMNS nodes and links
print("Generating GMNS nodes and links...")
nodes, links = gtfs2gmns_converter.gen_gmns_nodes_links()

# Print outputs to verify
print("Nodes DataFrame:")
print(nodes.head())  # Print first few rows of the nodes DataFrame

print("Links DataFrame:")
print(links.head())  # Print first few rows of the links DataFrame

###############################################################################################
# Generate access links if zone.csv is available
print("Generating access links...")
zone_path = './zone.csv'  # Update this path to your actual zone file location
node_path = f"{gtfs_output_dir}/node.csv"  # Assuming nodes are saved as node.csv in the GMNS directory
radius = 500.0  # Define your desired radius for linking zones to nodes
k_closest = 5  # Optional: define the number of closest nodes you want to connect to each zone

# Generate and print access links
access_links = gtfs2gmns_converter.generate_access_link(zone_path, node_path, radius, k_closest)
print("Access Links DataFrame:")
print(access_links.head())

# Save access links to a CSV file
access_links.to_csv(f"{gtfs_output_dir}/access_links.csv", index=False)
print("Access Links saved to access_links.csv.")

Main steps in gtfs2gmns code

1. Read GTFS data

1.1 Read routes.txt

• route_id, route_long_name, route_short_name, route_url, route_type

1.2 Read stop.txt

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

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

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

2. Building service network

2.1 Create physical nodes

• physical node is the original stop in standard GTFS

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

2.3 Create physical arcs

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

2.4 Create service arcs

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

Functions and Attributes

func_type	func_name	Python example	Input	Output	Remark
read-show	agency	gg.agency	NA	DataFrame	This attribute load and return agency data from source folder
	calendar	gg.calendar
	calendar_dates
	fare_attributes
	fare_rules
	feed_info
	frequencies
	routes
	shapes
	stops
	stop_times
	trips
	transfers
	timepoints
	timepoint_times
	trip_routes
	stops_freq
	routes_freq
	rute_segments
	route_segment_speed
	vis_stops_freq
analysis	vis_routes_fres
	vis_route_segment_speed
	vis_route_segment_runtime
	vis_route_stop_speed_heatmap
	vis_spacetime_trajectory
	equity_alanysis
	accessibility_analysis
	load_gtfs
	gen_gmns_node_link
visualization

Visualization

You can visualize generated networks using NeXTA or QGIS.

Upcoming Features

• Map matching transit network and auto network.
• Set the time period and add vdf_fftt and vdf_freq fields in link files.
• Add Visualization functions
  • Stops
  • Routes
  • ...