ICTCT workshop Nagoya Proceedings Intersection and Network Management 1 ISA EFFECT ASSESSMENT: FROM DRIVING BEHAVIOUR TO TRAFFIC FLOW Jeroen Hogema¹, Henk Schuurman², Chris M.J. Tampère³ ¹ TNO Human Factors P.O. Box 23 - 3769 ZG Soesterberg - The Netherlands hogema@tm.tno.nl ² Rijkswaterstaat, Transport Research Centre (AVV) P.O. Box 1031 - 3000 BA Rotterdam - The Netherlands h.schuurman@avv.rws.minvenw.nl ³ TNO Inro PO Box 6041- 2600 JA Delft - The Netherlands cta@inro.tno.nl ABSTRACT This paper discusses two complementary methods for ISA effect assessment, and how to apply them in a coherent manner. The first level consists of the effects on individual driving behaviour, typically measured with an instrumented vehicle or a driving simulator. Results at this level form the starting point for the second level, which consists of microscopic traffic flow simulation. ISA system characteristics and behavioural effects should be incorporated in the traffic simulation model. The main focus of the paper is on an explorative case study, in which the MIXIC model was applied to study the effects of a dynamic ISA system. The ISA penetration level was varied as an independent variable. The in-car control unit consisted of a mandatory ISA The road configuration that was studied of consisted of a lane drop from 3 to 2 lanes, and the roadside part of the ISA system determined the actual ISA speed limit based on the traffic state. The driver model was adjusted to take into account the set speed of the in-car ISA system, but otherwise, no strategic changes in driving behaviour were assumed. Results shows a decrease in throughput (volume) combined with positive effects on safety (shock waves, speed variance) when ISA is introduced. For the validation of these results more research into the driver’s behaviour in the presence of ISA is recommendable. INTRODUCTION The application of new technologies in road traffic (Advanced Transport Telematics, ATT) may contribute to a more efficient use of the existing infrastructure for traffic and transportation, to improve traffic safety and reduce the environmental impact. Increasingly, advanced systems within cars and along the road will change the driving task considerably. Systems that inform and support the driver or even take over parts of the driving task (Advanced Driver Assistance Systems: ADAS) are emerging with perhaps a fully automated vehicle guidance (AVG) concept for the further future. For the moment, the developments