TAP-B

Fast, efficient C implementation of algorithms for the traffic assignment problem. Default solution method is Algorithm B, developed by Robert Dial. Link-based solution methods (MSA, Frank-Wolfe, conjugate and biconjugate Frank-Wolfe) are also provided. Main implementations are by Steve Boyles. Parallelization capabilities were added by Rishabh Thakkar and Karthik Velayutham. This project is part of UT Austin's SPARTA (Simulation, Pricing, Adaptive Routing, and Traffic Assignment) lab.

Getting Started

These instructions will get you a copy of the project up and running on your local machine for development and testing purposes. The main option is to compile the code either for parallelization (default) or serial implementation. Primary implementation and testing has been done in a Linux ecosystem. Windows and Mac testing is ongoing; if you encounter difficulties in compiling, try to make the serial build. If you want to use the parallel version in Windows, the easiest method is to use WSL (the Windows Subsystem for Linux).

Configurations

Input parameters are specified through a text user interface (TUI). See net/SiouxFalls_parameters.txt for a simple example of such a file; at a minimum it must specify the network and trip table files, and at least one convergence criterion (small gap, max time, or max iterations). To see all possible parameter settings, see net/params_example.txt

Installation/Usage

First make sure to clone the repo as such:

git clone https://github.com/spartalab/tap-b.git

To build an executable of TAP-B, simply run the following:

make

This creates a "standard" build with parallelization, and without compiler optimization. If you have difficulties with the parallel version, run

make serial

to turn off parallelization options.

If you want additional performance, run

make release

to turn on additional compiler optimizations.

If you want to perform additional development, run

make debug

which turns off optimization but adds debugging symbols.

Contributing to TAP-B

As of Fall 2024, the repository is being cleaned up and transitioned to a more organized structure, using the Gitflow branching model. See here for more on Gitflow. The key points are as follows:

• The master branch will always point to a stable release, each of which will have an associated version number as tag, and a set of release notes.
• If you are working on a new feature, always branch off of develop (not master). The develop branch is used for features under development, experiments, or other changes. Each branch should have a branch.txt file in the root directory briefly stating the purpose of the branch.
• The only branches off of master will be to fix significant bugs as a hotfix.
• When a new feature is complete, merge it back into develop (not master).

This transition is currently in progress, identifying active branches which need to be merged, and other branches still with potential for development. When complete, the master branch will point to the v1.0 release, and other incomplete branches will be migrated to develop. Some inactive branches will not be moved to develop if I do not believe they have potential to enter the main code base in the future (e.g., bespoke changes for past projects).

If you have any questions, please contact [email protected].