An Open-Sourced Network-Based Large-Scale Simulation Platform for Shared Mobility Operations

Background

Establish an open-sourced network-based simulation platform for shared mobility operations. The simulation explicitly characterizes drivers’ movements on road networks for trip delivery, idle cruising, and en-route pick-up.

Contributions

• We develop a comprehensive, multi-functional and open-sourced simulator for ride-sourcing service, which can be used by both researchers and industrial practitioners on a variety of operational tasks. The proposed simulation platform overcomes a few challenges faced by previous simulators, including the closeness to reality, representation of customers’ and drivers’ heterogeneous behaviors, generalization for different tasks.

• The simulator provide interfaces for the training and testing of different tasks, such as testing of optimization algorithms, training/testing of reinforcement learning based approaches for matching and repositioning, evaluations of economic models for equilibrium analysis and operational strategy designs.

• Based on a vehicle utilization based validation task, some RL based experiments, and one task for theoretical model evaluation, the simulator is validated to be effective and efficient for ride-sourcing related researches. In the future, the simulator can be easily modified for completing other tasks, such as dynamic pricing, ride-pooling service operations, control of shared autonomous vehicles, etc.

Install

1. Download the code

   git clone git@github.com:HKU-Smart-Mobility-Lab/Transportation_Simulator.git

2. Pull the docker image

   docker pull jingyunliu663/simulator

• after running the code, you can use docker images to check whether the image is available
• the docker image comes with the conda environment new_simulator and the mongoDB service running in background within the container

3. Run the docker image & get a docker container

   docker run -d -e CRYPTOGRAPHY_OPENSSL_NO_LEGACY=1 -v /path/to/the/Transportation_Simulator:/simulator/scripts --name simulator jingyunliu663/simulator

   • Arguments:
   • -d: detach, run in background
   • -v path/to/your/local/file/system:/path/to/your/target/directory/inside/container: This will mount the local directory into the container. Any changes made to the files in this directory within the container will also be reflected on the local host system, and vice versa.
   • --name: name the container as simulator
   • the last argument is the image name (after all, container is a running instance of an image)

• you can use docker ps to check the running containers

4. Enter the interactive shell of the conatiner simulator

   docker exec -it simultor /bin/bash

• After enter the interactive shell , you will be in the working directory /simulator, you can navigate yourself to /simulator/scripts directory (the directory you choose to mount to) to run the main function
• You have to activate the conda environment: conda activate new_simulator

Download Data

Here, we provide you data for Manhattan that we used in our experiments. You can download it from Onedrive.(https://connecthkuhk-my.sharepoint.com/:f:/g/personal/ctj21_connect_hku_hk/EuHy9dMKNy1CkZf5K87GMlYBAI54ZPeGzjanbrpBTZO5CQ?e=95BBYF). And due to the data privacy, we can not provide you the data for Hong Kong and Chengdu.

Survey Data

We conducted a survey in NYC, and one hundred people participated in this survey. The content and results of the questionnaire can be found in the Survey_E-hailing_Taxi_Service_Studies.xlsx file. Hope that this data can help you for your research. And if you use these data in your research, please cite our paper: Feng S., Chen T., Zhang Y., Ke J.* & H. Yang, 2023. A multi-functional simulation platform for on-demand ride service operations. Preprint at ArXiv:2303.12336. https://doi.org/10.48550/arXiv.2303.12336.

File Structure

- simulator
-- input
  -- graph.graphml
  -- order.pickle
  -- driver_info.pickle
-- output
  -- some output files
-- test
  -- test scripts
-- utils
  -- driver_generation.py
  -- find_closest_point.py
  -- handle_raw_data.py
-- dispatch_alg.py
-- simulator_pattern.py
-- simulator_env.py
-- A2C.py
-- sarsa.py
-- main.py
-- config.py
-- LICENSE.md
-- api_doc.md
- readme.md

Data preparing

There are three files in 'input' directory. You can use the driver data and order data provided by us. Also, you can run python handle_raw_data.py to generate orders' information, run python driver_generation.py to generate drviers' information.

In config.py, you can set the parameters of the simulator.

't_initial' # start time of the simulation (s)
't_end'  # end time of the simulation (s)
'delta_t' # interval of the simulation (s) 
'vehicle_speed' # speed of vehicle (km / h)
'repo_speed'  # speed of reposition
'order_sample_ratio' # ratio of order sampling
'order_generation_mode'  # the mode of order generation
'driver_sample_ratio' : 1, # ratio of driver sampling
'maximum_wait_time_mean' : 300, # mean value of maximum waiting time
'maximum_wait_time_std' : 0, # variance of maximum waiting time
"maximum_pickup_time_passenger_can_tolerate_mean":float('inf'),  # s
"maximum_pickup_time_passenger_can_tolerate_std"
"maximum_price_passenger_can_tolerate_mean"
"maximum_price_passenger_can_tolerate_std"
'maximal_pickup_distance'  # km
'request_interval': 5,  #
'cruise_flag' :False, # 
'delivery_mode':'rg',
'pickup_mode':'rg',
'max_idle_time' : 1,
'cruise_mode': 'random',
'reposition_flag': False,
'eligible_time_for_reposition' : 10, # s
'reposition_mode': '',
'track_recording_flag' : True,
'driver_far_matching_cancel_prob_file' : 'driver_far_matching_cancel_prob',
'input_file_path':'input/dataset.csv',
'request_file_name' : 'input/order', #'toy_requests',
'driver_file_name' : 'input/driver_info',
'road_network_file_name' : 'road_network_information.pickle',
'dispatch_method': 'LD', #LD: lagarange decomposition method designed by Peibo Duan
# 'method': 'instant_reward_no_subway',
'simulator_mode' : 'toy_mode',
'experiment_mode' : 'train',
'driver_num':500,
'side':4, # grid side length
'price_per_km':5,  # ￥ / km
'road_information_mode':'load',
'north_lat': 40.8845,
'south_lat': 40.6968,
'east_lng': -74.0831,
'west_lng': -73.8414,
'rl_mode': 'reposition',  # reposition and matching
'method': 'sarsa_no_subway',  #  'sarsa_no_subway' / 'pickup_distance' / 'instant_reward_no_subway'   
'reposition_method' #2C_global_aware',  # A2C, A2C_global_aware, random_cruise, stay  

Real Road Network Module

We use osmnx to acquire the shortest path from the real world. You can set 'north_lat', 'south_lat', 'east_lng' and 'west_lng' in config.py , and you can get road network for the specified region.

Mongodb Module

If your road network is huge, yu can use mongodb to store the road network information and add index on node id which uniquely identifies a node on the road network. You can use the following code to connect your local database route_network and collection route_list which stores the information. After that, you can use find_one interface to achieve the shortest path list easily.

myclient = pymongo.MongoClient("mongodb://localhost:27017/")
mydb = myclient["route_network"]
mycollect = mydb['route_list']

re_data = {
            'node': str(ori_id) + str(dest_id)
        }
re = mycollect.find_one(re_data)

Price Module

You can set the maximum order price that is normally distributed and acceptable to passengers by modifing maximum_price_passenger_can_tolerate_mean' and maximum_price_passenger_can_tolerate_std.

Cruising and Repositioning Module

Dispatching Module

In dispatch_alg.py, we implement the function LD, we use binary map matching algorithm to dispatch orders.

Experiment

You can modify the parameters in config.py, and then excute python main.py. The records will be recorded in the directory named output.

Tutorials

Technical questions

We welcome your contributions.

• Please report bugs and improvements by submitting GitHub issue.
• Submit your contributions using pull requests.

Contributors

This simulator is supported by the Smart Mobility Lab at The Univerisity of Hong Kong and Intelligent Transportation Systems (ITS) Laboratory at The Hong Kong University of Science and Technology.

Ownership

The ownership of this repository is Prof. Hai Yang, Dr. Siyuan Feng from ITS Lab at The Hong Kong University of Science and Technology and Dr. Jintao Ke from SML at The Univerisity of Hong Kong.

Cite

@article{feng2024multi, title={A multi-functional simulation platform for on-demand ride service operations}, author={Feng, Siyuan and Chen, Taijie and Zhang, Yuhao and Ke, Jintao and Zheng, Zhengfei and Yang, Hai}, journal={Communications in Transportation Research}, volume={4}, pages={100141}, year={2024}, publisher={Elsevier} }