Tesla MODEL S 2012 Owner's Manual page 91

WARNING: Navigate on Autopilot may not always
attempt to exit at an off-ramp or change lanes,
even when an exit or lane change is determined by
the navigation route. Always remain alert and be
prepared to manually steer onto an off-ramp, or
make a lane change to prepare for, or to exit at, an
off-ramp or interchange.
Be Ready to Assist
When attempting to change lanes or maneuver Model S,
or when approaching construction zones, Navigate on
Autopilot may be unable to determine the appropriate
driving lane (for example, complex clover leafs and
multi-lane off-ramps) and the instrument panel displays
an alert indicating that Navigate on Autopilot is trying to
maneuver and may require assistance. When you see the
message, be prepared to take immediate action to
ensure that it is safe and appropriate to complete the
lane change or maneuver.
Autopilot
Navigate on Autopilot
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