FAQ

What is AequilibraE?

AequilibraE is a transportation modelling add-on for QGIS, which is intended to be a full-fledged transportation modelling platform, leveraging very efficient algorithms and the best open source GIS platform available in the market. AequilibraE, however, does not intend to compete with or replace available commercial software rather it is to serve as a great alternative for projects of low to medium complexity, with the added advantage of being free.

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Why is it been developed?

AequilibraE’s development is motivated by the cumbersome nature of most if not all the free transportation planning tools available in the market today. Another motivation is the high cost of acquiring commercial transportation software licence(s).Lastly and very crucially, commercial software is usually a black box which precludes users from accessing the intermediate results of their algorithms for building new algorithms and tools, which is paramount for research.

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Target users

Students and researchers that want full control over the tool being used will be the most likely users of this tool. Smaller planning agencies and independent consultants that lack the resources to purchase commercial software might leverage the use of AequilibraE in a professional environment. Lastly, open-Source enthusiasts that plan to develop AequilibraE further and hone their programming skills in the way might also form an important set of users.

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Computational performance

Two topics that are central to the computational performance of the AequilibraE package are:

• Algorithm implementation In terms of algorithm implementation, it is important to highlight that the package's algorithms are written in a mix of Python and Cython, with the really intensive ones (e.g. traffic assignment) written in Cython, while the rest is written in Python.
• Data reading and Writing through QGIS. Regarding data reading, it should be noted that reading data from layers (data only or shapefiles) through QGIS is rather slow, which might result in longer run times due specifically to data reading. This architecture, however, addresses this concern since it is able to read data directly from disk due to its better user interface.

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User proofing

Arguably one of the most important features of a good software is being user-proof. Although there has been some time and effort spent in trying to make the software catch errors before they occur instead of having python raising errors and exceptions, AequilibraE is work in progress and there is still much to be done in this area.

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