Development of a GIS based transport demand estimation model that integrates land use and transportation infrastructure development scenarios

Abstract

Transportation issues are becoming severe day by day in Sri Lanka. Ignoring the importance of integrating transport and land use properly in the travel demand estimation process, due to its vast complexity and not having a proper mechanism to understand it easily, is the main reason for those issues. Identifying that, this research developed a GIS based transport and land use model that helps relevant authorities to easily understand and incorporate the complex interaction to the travel demand estimation process, as the first attempt in Sri Lanka until now. The model has two sub models called macro and micro models that separately look after the regional level and local level travel demand estimations respectively, although final results at any level combine both models’ outputs. The macro model has been developed for whole Sri Lanka taking the Divisional Secretariat (DS) divisions as Traffic Analyzing Zones (TAZs). Algorithms calibrated by the linear regression analyzing technique incorporating the Origin-Destination (OD) matrix data and socio-economic data are the main modeling technique for the macro model. Optimum counting locations derived through a new approach named as the “top-down approach” for OD surveys enhanced the accuracy of the OD matrix and thereby increasing the accuracy at all stages. As a prototype, a micro model was built for the Colombo DS division. The study area of the micro model can be any geographic area according to data and time availability. The activity based approach in the microsimulation modeling technique was used to develop the micro model, which uses household and railway passenger OD surveys, for calibration. Finally, a GIS based computer program was developed to improve the effectiveness and user-friendliness of these models.