An innovative travel model system for western cape

Abstract

In 2018, the Western Cape Department of Transport and Public Works retained Bentley Systems (formerly Citilabs) and Esri SA to develop the Western Cape Land Use/Transportation Interaction model. This model provides the ability to test a wide variety of demographic and multimodal transport system changes in support of a new performance-based planning process. This model is innovative and unique in several respects: 1) It is an integrated person travel/goods movement/land use forecasting process, in which the transport system influences growth, which in turn influences the system. 2) The person travel model uses the new type of tour-based structure. Instead of zonal averages, choice probabilities are used to simulate the decisions of individual travellers. 3) Land use is modelled applying bid-rent mechanics to achieve an equilibrium between real estate supply and demand and accounts for informal development. 4) The goods movement component uses a commodity flow model, translating macroeconomic and demographic data into the flow of material by mode and estimating truck travel on roads. Developing a new travel model usually requires significant data on demographics and existing travel patterns, which is largely unavailable in South Africa. Thus, the models are crafted from a combination of local information and behaviour transferred from other areas. The household synthesis component was calibrated from Stats SA data. Demand is estimated using several components: tour frequency, destination choice, mode choice, intermediate stops, time of day, and trip assignment. The model is developed using Cube software. As of mid-2020, the model system was calibrated, tested, and documented. The project’s final year will see some enhancements, more testing, and additional staff training.