Lexus 2013 IS250 Owner's Manual page 245

Turning the LDA system on
Press the LDA switch to activate
the system.
The LDA indicator and lane lines
will come on.
Press the switch again to turn the
LDA system off.
The LDA system will remain on or
off even if the engine switch is
turned to IGNITION ON mode.
Operating conditions

When the vehicle speed is approximately 50 km/h (32 mph) or more

When the lane width is more than approximately 2.5 m (8.2 ft.)

When driving on a straight road or through a curve with a radius of
more than approximately 100 m (328 ft.)
IS250_EE(OM53B11E)
4-5. Using the driving support systems
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