Owner’s Manual

How Speed Assist Works
If Model S is equipped with Driver Assistance
features, a camera mounted on the windshield
behind the interior rear view mirror detects
speed limit signs. The signs are then analyzed
and compared against GPS data to determine
the speed limit at your current driving
location. For routes where no signs are
present, speed limits are determined using
GPS data (if available). Instead of determining
the speed limit based on signs and GPS data,
you can also manually enter an arbitrary
speed limit.
When you turn on Speed Assist, the
speedometer displays a gray line to indicate
the speed limit. Warnings (described below)
take effect when you exceed this limit.
In situations where the system does not have
confidence in the acquired speed limit, the
speedometer displays a dashed line instead,
and warnings do not take effect. The system
may be uncertain about a speed limit if a
speed, although initially detected, is no longer
known or may no longer apply. In some cases,
the dashed line displays at the originally
detected speed, whereas in other cases it
displays at 0 mph.
If you set the speed limit warning to Display
(see Controlling Speed Assist below), a speed
limit sign displays in the center of the
instrumental panel whenever you exceed the
speed limit and the speedometer displays the
excess speed in gray.
Note: A speed limit sign also displays in the
center of the instrumental panel when an
automatically detected speed limit changes.
If you set the speed limit warning to Chime
(see Controlling Speed Assist) and exceed the
speed limit, the speedometer displays excess
speed in gray, and you also hear a warning
chime.
Note: Speed limit warnings go away
automatically after 10 seconds, or when Model
S slows down below the specified limit.
Warning:
Do not rely on Speed Assist to
determine the appropriate speed limit.
Speed Assist
Driving 55