In conjunction with the Department of Transport and Main Roads, SCRC has developed a four-step model of the Sunshine Coast -- the Sunshine Coast Integrated Multi-Modal Model (SCIMMM). It contains 1645 zones covering the whole Sunshine Coast region, including Noosa Shire. Even though this does contain quite a high level of spatial detail, in some areas the zones are large enough that they limit the ability to perform local area analysis, particularly when looking at micro-simulation or detailed intersection analysis. For this reason it is useful to be able to further split the SCIMMM zones into smaller areas.
SCRC is reasonably well equipped with the data needed to split the demand into smaller areas, as it has access to lot level information on existing land use and forecast changes. The difficulty in bringing together data from disparate sources to inform the calculation of split factors and to have visibility and control on the assumptions used in these calculations.
Previous work done by Council and its advisors have produced a methodology for this, but it is cumbersome and error prone. Furthermore it has inputs, assumptions and output all mixed together in a way that makes it sometimes difficult to understand or explain. This limits the ability of Council officers to stand by the results of their analysis, or explain the outcomes to stakeholders or constituents.
This project involved reviewing and critiquing the approach previously implemented, then simplifying and optimizing the process to calculate the zone splitting factor. The new algorithm is designed to combine data from different sources based on their geometry information and estimate the number of trips in the areas which the model defines for calculating the traffic split factors. The algorithm was implemented and delivered as a package in python.