80 PART | II ITS users
vehicle, compare it to a limit that is usually a little higher than the speed limit
at this section, and transmits a warning signal, if the speed exceeds the limit.
Consequently, the direct effects of the system are reduction in speed and in-
crease in deceleration. Indirectly, there is effect of using the system to increase
the speed to other road sections to offset its reduction, the more aggressive
driving (e.g., more or more dangerous overtaking maneuvers), its large number
of fluctuations speed, etc. Therefore, both direct and indirect effects should be
investigated for each system (or type), so as to assess how driver behavior is
influenced.
Moreover, ITS can be interconnected with the driver in three ways, that is,
information systems, warning systems, and intervention systems. It has been
found that the higher the degree of intervention of the system, the more effec-
tive it is in terms of their targeted operation. At the same time, different ways
of interfacing result in different indirect effects such as distraction, frustration,
varying degrees of compensation, etc. Finally, the type of signals transmit-
ted can affect driving behavior. For example, acoustic signals are thought to
irritate drivers more but at the same time are more effective than optical and
tactile.
6.3 Impact of the development of ITS to travelers and road
users
The first who are benefited from an ITS are the travelers (also called end-users)
and the drivers (or road-users). An ITS provides drivers and travelers with in-
creased security, rich information about their travels, shorter routes and shuttle
times, easier access to parking, etc. Pedestrians and other vulnerable groups are
safer and become a priority of the transportation system. The users of public
transport have more travel options and rich information during their travels.
Finally, the transport infrastructure is better monitored and preventively main-
tained, thus reducing damages and providing faster recovery in emergencies
(extreme weather conditions, major accidents, etc.). The integration of ITS ser-
vices has many benefits for all the groups of users, can improve the effective-
ness at all cases, even in emergencies, and allow to develop advanced services
that facilitate everyone.
However, in order to get these advantages users have to contribute some-
thing too. For example, in order to have correct estimations of the travel time,
it is necessary to collect vehicle location and speed data. For guaranteeing driv-
er’s accountability in accidents and increase pedestrian and passengers’ safety,
it is required to monitor vehicles and driver's condition at any moment. On the
other side, continuous monitoring may be considered a violation of driver's
personal lives, or an unwarranted interference to driver's liberty. Similar issues
rise around the role of driving-assistance modules in the car, that may increase
driver’s and passengers’ safety and improve driving comfort but may decrease
driver awareness. So, others are negative in sharing personal information or