Application of cell transmission model for heterogeneous and non-lane-disciplined traffic

摘要

Traffic congestion continues to remain a major problem in most cities around the world, resulting in enormous delays, increased fuel consumption and a loss to the economy. Traffic flow modelling is an important part of transportation engineering and traffic management. A number of mathematical models have been developed for microscopic and macroscopic travel flow modelling to predict the behavior of traffic in planning, design and operation of the road traffic networks. Cell Transmission Model (CTM) is one of the most widely used macroscopic traffic flow models and now being used in various simulation and optimization packages. This research calibrates CTM for heterogeneous and non-lane disciplined traffic, as observed in Pakistan and some other developing countries by constructing a flow-density fundamental traffic flow diagram. Currently, most of the traffic simulation packages used for such heterogonous and non-lane-disciplined traffic are not calibrated for local traffic conditions and most of the traffic flow models are developed for comparatively less heterogeneous and lane-disciplined traffic. The flow-density fundamental traffic flow diagram is developed based on extensive field data collected from Karachi, Pakistan. The calibrated CTM model is validated by using actual data from another road and it was concluded that CTM is capable of modelling heterogamous and non-lane disciplined traffic and performed very reasonably. The calibrated CTM will be a useful input for application of traffic simulation and optimisation packages.