A GIS-Based Integrated Model for Exploring Effects of Land Use Changes on Transport Demand: The Case of Dar es Salaam, Tanzania

Abstract

Land use patterns essentially determine activity centre locations and opportunities for trip generation and attraction. Land uses signify the magnitude of travel demand and availability of transport patterns influence s the future land uses. A number of literatures on land use and transport interactions show that the effects of land use change on transport appear to be more direct and stronger than the reverse. The main cause, in large part, is the important roles of trip generation and attraction, whose change of spatial distribution basically increase s the number of trips and distances travelled between activity centres. Ignoring the mutual influences for the change between land use and transportation in long-term forecasting and planning can lead to decisions with unintended and undesirable consequences. This is more critical in developing countries cities where long-term travel demand forecasting and transportation infrastructure planning is seldom done as well as changes in land use are considerably high compared with the supply of transport infrastructure. This paper therefore reports upon a GIS-based integrated land use and transport model developed to determine effects of land use changes on travel demand. The model is developed based on vector map layers of the planned land uses, and changes obtained by overlaying the subsequent layers in ten-year intervals obtained from satellite images. The model is capable of performing a spatial-temporal analysis of land uses and illustrating effects on travel demand. The modelling system also supports analysis of policy measures that alternatively reduce the number of vehicle trips generated in the planned area.