Analisi degli effetti indotti dalla funzionalità stradale sulla sicurezza ...

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Abstract
Road safety is one of the most crucial problems all over the world.
Traditional approach to the design of safe roads is based on kinematical
and dynamic equations that impose geometrical requirements for each
single element, neglecting human factors and driver’s behaviour without
taking adequately into account traffic flows.
The increase of traffic flows causes a severe problem of vehicle
interferences when the levels of service of the road decrease. It has a
relevant impact on safety. At the same time, the high value of vehicles
density is determined by the overlapping of traffic flows generated by
different motivations.
International literature agrees that road safety is affected by human
factors. This should suggest to engineers that driver’s behaviour has to be
considered more in depth and that an interdisciplinary approach to road
project is strongly recommended.
Emerging technologies of simulation in virtual reality make it possible to
evaluate the interaction among driver, vehicle and road environment
(traffic, geometry, pavement, external conditions) through an
interdisciplinary approach.
Many virtual reality experiments developed in this thesis pointed out that
the risk accepted by drivers crucially depends on road geometry and
traffic conditions. Results allow to propose some laws and procedures to
formulate the quality audit of road project under safety perspective with
the great advantages of simulated environment experiments.
The application of the theory to many case studies of rural roads points
out the validity of the model for the evaluation of the expected accident
occurrence as a function of the level of discomfort suffered by road users.
Results suggest to take into account in road projects an in depth analysis
of traffic flows (in terms of volume, composition, variability, motivation),
of road geometry from a systemic point of view, of driver’s expectations,
desires, perception and his behaviour influenced by road characteristics
and operating conditions.