GMC 1999 Sierra 1500 Pickup Owner's Manual page 187

Pavement Markings
NO PASSING ZONE
AM40201 6
Pavement markings add to traffic signs and signals. They give information to
drivers without taking attention from the roadway. A solid yellow line on your
side of the road or lane means "don't cross."
Your Own Signals
Drivers signal to others, too. It's not only more polite, it's safer to let other
drivers know what you are doing. And in some places the law requires driver
signals.
Turn and lane change signals: Always signal when you plan to turn or
change lanes.
If necessary, you can use hand signals out the window: Left arm straight out
for a left turn, down for slow or about-to-stop, and up for a right turn.
Slowing down: If time allows, tap the brake pedal once or twice in advance
of slowing or stopping. This warns the driver behind you.
Disabled: Your four-way flashers signal that your vehicle is disabled or
is
a
hazard. See "Hazard Warning Flasher" in the Index.
Traffic Officer
The traffic police officer is also a source of important informaaon. The officer's
signals govern, no matter what the traffic lights or other signs say.
The next part discusses some of the road conditions you may encounter.
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