Toyota Prius 2011 Manual page 246

2-4. Using other driving systems
Indication on the multi-information display
While the LKA system is on, the lane line display and steering wheel
display (in case of lane keeping assist function) are shown on the
multi-information display to inform that the LKA system is on.
246
Steering wheel display
The lane keeping assist function
is active.
Dynamic radar cruise control
display
Lane line display
When thin lines are shown:
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A lane marking is not recognized
by the system, or the LKA system
functions are temporarily can-
celed. (When the lane keeping
assist
buzzer will beep twice.)
When solid lane lines are shown: 
The lane departure warning func-
tion is active.
function is canceled,