Toyota Prius 2011 Manual page 262

2-4. Using other driving systems
CAUTION
Cautions regarding the assist contents of the system
■
By means of alarms and brake control, the pre-collision system is intended
to assist the driver in avoiding collisions through the process of LOOK-
JUDGE-ACT. 
There are limits to the degree of assistance the system can provide, so
please keep in mind the following important points.
●
Assisting the driver in watching the road
The pre-collision system is only able to detect obstacles directly in front of
the vehicle, and only within a limited range. It is not a mechanism that
allows careless or inattentive driving, and it is not a system that can assist
the driver in low-visibility conditions. It is still necessary for the driver to
pay close attention to the vehicle's surroundings.
●
Assisting the driver in making correct judgment
When attempting to estimate the likelihood of a collision, the only data
available to the pre-collision system is that from obstacles it has detected
directly in front of the vehicle. Therefore, it is absolutely necessary for the
driver to remain vigilant and to determine whether or not there is a possi-
bility of collision in any given situation.
●
Assisting the driver in taking action
The pre-collision system's braking assist feature is designed to help
reduce the severity of a collision, and so only acts when the system has
judged that a collision is unavoidable. This system by itself is not capable
of automatically avoiding a collision or bringing the vehicle to a stop safety.
For this reason, when encountering a dangerous situation the driver must
take direct and immediate action in order to ensure the safety of all
involved.
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