Loki

Tips and tricks to fluidify your (public) transit !

Build status	Code Coverage

Description

This is a work-in-progress implementation of a multicriteria public transit engine. The goal is to have an engine that computes a set of pareto-optimal journeys for public transit, but with an engine generic enough to handle any criteria specified by a partial order.

Note that the engine handle only the 'public transit' part of the journey. It assumes that the fallbacks (from the actual starting point to the entrance of the public transit network, as well as from the exit of the public transit network to the actual destination) are given as input.

Repository Architecture

The root of the repository provides the loki library, which allow to perform public transit requests on a ntfs/gtfs dataset (read with transit_model).

The library can be used with :

• the stop_areas subcrate, where you can provides the origin and destination as command line arguments,
• the random to perform benchmarks by generating random requests.
• as a server with the server subcrate, which process protobuf journey requests (the format is specified by the navitia-proto repo) sent to a zmq socket, call the loki engine, and return protobuf responses on the zmq socket.

In order to provide a fully-fledged multimodal journey planner, the server needs other Navitia components as well as data. These components are bundled together in ./dockers, and some ready to use data is provided in ./data. See the docker-readme for usage.

Development

To be able to compile this project, you'll need to:

• initialize the submodule that brings protobuf description for Navitia
• have libraries for zmq and PostgreSQL
• have the lld linker (faster than the default ld) which is not installed on most default Linux distributions

git submodule update --init --recursive
sudo apt install libzmq3-dev libpq-dev lld

Acknowledgments

This contribution is a part of the research and development work of the IVA Project which aims to enhance traveler information and is carried out under the leadership of the Technological Research Institute SystemX, with the partnership and support of the transport organization authority Ile-De-France Mobilités (IDFM), SNCF, and public funds under the scope of the French Program "Investissements d’Avenir".