Unlimited Modelling Dimensions
Transport modelling involves analysing, over time and space, the interactions between the demand for transport services (i.e. millions of people and freight movements) and its supply in the form of a transport network infrastructure and a wide range of transport providers. These interactions are influenced by the behaviour and preferences of individuals and nowadays, the modelling of these interactions can be calibrated against a wide range of available information (surveys, road detection devices, GPS tracks, etc.). Transport modelling therefore implies manipulating a huge amount of data and carefully structuring it to make the task manageable.
From the outset OmniTRANS has been designed to facilitate data management and model development via its core concept of dimension based on six key dimension types.
- Purpose
- Mode
- Time Period
- User or Commodity Segmentation
- Results
- Iterations
The structural content of these dimensions is unlimited, user-defined and established when building a project. The content of the dimensions can be amended at any time and can be arranged hierarchically facilitating the aggregation of data as well as the analysis and synthesis of results. The important point is that you are free to define the dimension hierarchy and to organise it according to your thinking and needs.
All data and processes integrate theses key dimension types in their construct. Travel demand matrices are organised and stored around the first four dimension types, allowing the modelling of any combination of travel purposes, modes, time periods and user segmentation.
Networks are associated with two dimension types, Mode and Time Period, so that the same network can be seen from any combinations of mode and time perspectives. The multi-modal structure makes the modelling of interactions between any motorised and non-motorised modes possible while the multi-temporal structure permits the modelling of travel demand, network infrastructure or transport measures that changes over time (e.g. time varying signalling schemes at junctions, different prices for different time periods, opening/closing of an express lane, etc.).
The Result and Iteration dimension types ease the organisation and storage of model outputs and facilitate the analysis of results. For example, you can explore different assignment techniques using the same input data while storing the output in separate results dimensions. The dimension hierarchy is an integral part of reports, charts and plots making the comparison of results effortless.
The user-defined dimensions are directly accessible within the OmniTRANS Job Language making it possible to define processing loops that extend over the chosen dimensions. It permits the sophisticated modelling of demand schemes at any level of aggregation, multi-modal static and dynamic assignment and the study of interactions between modes.
Whatever the dimension of interest, OmniTRANS is ready to model it.
