DEVELOPMENT OF A NOVEL INTELLIGENT SPEED ADAPTATION SYSTEM BASED ON AVAILABLE SIGHT DISTANCE

Roads are designed without considering the improved performance of modern vehicles and the new onboard technologies available for assisted driving. In addition, vehicles frequently travel at speeds which exceed the maximum considered in road design. Hence, the need for speed and safety related countermeasures (e.g., field control, mobile or fixed speed cameras, traffic calming measures) is evident. However, these countermeasures are only partially effective and the proportion of crashes which are speed related remains significant. This investigation is aimed at the development of a new Intelligent Speed Adaptation (ISA) system based on the available sight distance (ASD). In conditions of poor visibility, the system (i) inform drivers when they are travelling at inappropriate speeds, or (ii) generate warning sounds to the same effect, or (iii) intervene directly and compel drivers to adopt the speed which is most appropriate to the particular ASD. As reported in this methodological paper, the functionality of the new ISA system was tested at the driving simulator of the Politecnico di Torino (Italy) and the resulting estimated ASD value was validated and tested successfully. Future experimental investigations will be devoted to assessing the effectiveness of the system on driver speed behavior and decision making.