MICROSCOPIC SIMULATION OF FREEWAY TRAFFIC - PROBLEMS IN WIDENING THE USE OF SIMULATION PROGRAM

The application area of the traffic simulation program used in this study (HUTSIM) is widening to freeway surroundings. The new simulation environment causes new problems and development need to the program. The paper gives a discussion about the problems of microscopic freeway simulation based on general knowledge and experiences of a case study. Freeway as simulation environment requires a lot from the traffic simulation procedures. The interaction between drivers is very important. Realistic lane-change and car-following procedures have a great effect on the traffic flow and the lane distribution. Traffic has to be heterogeneous because the similarity of drivers gives too smooth traffic flow. Also the interaction between the driver and the environment and between the driver and the traffic control system should be calibrated carefully. The paper demonstrates that the use of a simulation tool is restricted by the environment where it has originally been developed and validated.