Traffic Controls (PDF) - AAA Carolinas

Traveling today’s roadways can be a
frustrating, confusing journey through
a maze of roadblocks, detours and
traffic jams. To help keep you safe,
traffic control devices are placed
along, beside, or above a highway,
roadway, or pathway. They are
instrumental in guiding, warning, and
regulating the flow of traffic,
including motor vehicles, bicycles,
pedestrians, and other travelers.
This brochure provides information
that can help you better understand
traffic control devices and their
importance in ensuring you are
prepared to travel the highways and
byways as safely as possible.

Purpose of
Traffic Control Devices
Wherever you travel in the United States, and
whatever mode of travel you choose, you are
guided by and expected to obey a common set
of roadway signs and markings. These traffic
control devices — signs, signals, pavement
markings and other devices — help move
vehicles and pedestrians safely and efficiently.
They are placed in key locations to guide traffic
movement, control vehicle speeds and warn of
potentially hazardous conditions. They also
provide important information to drivers about
detours and traffic delays.
The three basic goals of a traffic control device
are to:
• Attract attention;
• Convey a clear, simple meaning; and
• Give adequate time for response.
Signs, signals, pavement markings, cones,
barricades and warning lights feature dedicated
colors, shapes and sizes based on the different
functions they provide. Uniformity of design
(color, shape, size and location) helps drivers
quickly understand the messages of traffic
control devices. All of this helps ensure the safe,
efficient flow of traffic — whether you are
driving on the New Jersey Turnpike or walking
across a local road.
Characteristics of
Traffic Control Devices
Color — Certain colors are used to trigger
instant recognition and reaction. For example,
stop signs are always red. Similarly, signals at
intersections must have the same sequence of
red-yellow-green to communicate stop-warning-go
to drivers and pedestrians.
1

Nighttime visibility — Traffic control
devices are made visible under nighttime
operating conditions. They are either separately
lighted or made of reflective material so that
the light coming from vehicle headlamps is
bounced off signs and other devices back to the
eyes of drivers.
Daytime visibility — Traffic control devices
are designed with highly visible colors or a
sharp contrast of messages against a
background. Sometimes traffic control devices
are lighted even for daytime viewing to draw
attention to their messages.
Shape and size — Signs have standard
shapes and sizes to trigger instant recognition
and reaction. For example, stop signs have an
octagonal shape that no other sign is permitted
to have. There are similar specifications for the
shapes and sizes of many other traffic control
devices for both permanent and temporary
conditions.
Location — Traffic control devices must be
placed in locations that provide enough time for
drivers to make appropriate safe maneuvers,
such as entering or exiting a road or stopping
and turning to avoid conflicts with other
vehicles and pedestrians.
Messages — Traffic control devices are
designed with carefully chosen symbol or word
messages of specific sizes and content.
Placement is then determined by the amount of
time drivers need to detect, read and
understand messages to make appropriate
vehicle maneuvers.
2

Traffic Signs
Traffic signs are the most extensively used form
of traffic control devices in the United States
today. More than 55 million traffic signs line the
nation’s roadsides. They provide information
about speed limits and road conditions and they
direct traffic along certain routes and to specific
destinations. By using signs, traffic control
planners tell drivers what to do, what to watch
for, and where to drive.
Traffic signs are designed to provide uniform
instructions and guidance on distance and
destination. They provide information about
laws that apply, hazards and roadway design
features.
There are three basic types of traffic signs:
• Regulatory;
• Warning; and
• Guide and Informational.
Signs convey information to travelers with their
color. There are currently nine traffic sign colors,
and each has an exact meaning.
• Green is used as the
background color for guide
and information signs. Green
also is used for the legend on
permissive regulation and parking signs.
• Red is used for stop, yield, do not
enter and wrong way signs, for
text or symbols on some
regulatory signs, and as part of
Interstate and some state route markers.
• Blue is used as the background color
for traveler services information signs,
emergency evacuation route signs,
and as part of Interstate and some state route
3

markers. Blue signs also identify parking
spaces for disabled drivers.
• Orange is used as the
background color for
temporary traffic control
signs, construction and
maintenance signs.
• Brown is used as the
background color for guide
and information signs related
to points of recreational or cultural interest,
for example, public recreation areas and
scenic guidance.
• Yellow is used as the
background color for general
warning signs (temporary signs
not included) and school signs.
• White is used as the
background color for
most regulatory signs
and some route
markers. White also is
used as the text color on signs with red,
green, blue, brown, and black backgrounds.
• Black is used as the background
color on one way, night speed
limit, and truck regulatory signs.
Black also is used as the text color
on signs with white, yellow, orange, and
fluorescent yellow-green backgrounds.
• Fluorescent yellow-green is
used as the background color for
pedestrian, bicycle and school
warning signs.
4
Signs convey information to travelers not only
by their messages and color, but through their
shape as well. Because special shapes are
assigned to specific types of signs, travelers can

ecognize them quickly and react appropriately.
The shape of a road sign tells you as much
about the sign's message as its color.
• Octagon: Exclusively for
stop signs.
Stop signs are always octagonal
(eight-sided). A stop sign means
that you must bring your vehicle to a
complete stop before the marked stop line. A
four-way stop sign means that there are four
stop signs at this intersection. Traffic from all
four directions must stop. The first vehicle to
reach the intersection should move forward
first. If two vehicles reach the intersection at
the same time, the driver on the left yields to
the driver on the right.
• Triangle: Exclusively for
yield signs in the United
States.
A triangular sign means you are
to slow down and give vehicles
crossing your path the right-of-way. If the way
is clear, you may move forward slowly
without stopping. Yield signs are usually
placed where auxiliary roads lead into major
roads.
• Pennant: Advance
warning of no passing
zones.
A pennant sign means that
you are approaching a no passing zone. This
sign is placed on the left side of the road,
facing the driver.
• Diamond: Exclusively to
warn of existing or
possible hazards on
roadways or adjacent
areas.
These signs alert you of special conditions or
dangers ahead. Words or symbols on the sign
will show why you need to use caution. These
5

signs are generally yellow in color. Exceptions
are orange construction signs and fluorescent
yellow-green pedestrian signs.
• Pentagon: School advance
and school crossing signs.
These five-sided signs indicate
you are near a school. As you
approach these signs, slow
down and watch for children crossing the
road. Stop, if necessary, and obey signals
from any crossing guards.
• Horizontal Rectangle:
Generally for guide
signs.
These signs are usually rectangular, with the
longer dimension aligned in a horizontal
position. They are used for guide signs, some
warning signs, and temporary traffic control
signs. They provide information on routes,
exits, distances and services in advance time
for drivers to make safe, timely maneuvers on
the roadway.
• Vertical Rectangle:
Generally for regulatory
signs.
These signs tell you the law, so
you must follow their instructions.
The sign shows you what is not
allowed. Regulatory signs are red, black on
white or white on black. Remember that a red
circle with a slash means NO.
International Signs
Because many people travel worldwide, the
United States uses many easily recognized
international graphic symbols on traffic control
signs. Following are some examples of
international road signs you might encounter
while driving overseas. These signs are graphic
rather than textual in nature. As such, their
6

meaning tends to be easy to understand,
although some signs are less intuitive. The most
important information to remember is:
• Red triangles are warnings;
• Red circles are restrictions;
• Squares and rectangles give guidance;
• Blue circles are requirements;
• Diamond signs indicate priority.
Regulatory Signs
Stop Yield Maximum
Speed Limit
Traffic Warning Signs
Right Bend Intersection Uneven Road
Prohibitory Signs
No Entry
No Entry for
Power Vehicles
Closed to All
Vehicles
Traffic Signal Lights
The world’s first traffic light
came into being before the
automobile was in use, and
traffic consisted only of
pedestrians, buggies, and
wagons. Installed in 1868 at an
intersection in London, it was a
revolving lantern with red and green signals.
7

Red meant "stop" and green meant "caution."
The lantern, illuminated by gas, was turned by
means of a lever at its base so that the
appropriate light faced traffic.
Today, the traffic signal light continues as an
important part of our society and is one of the
most recognized traffic control devices. Traffic
signals keep us safe by controlling and directing
traffic and helping to protect pedestrians. They
are placed at intersections to keep traffic
moving and prevent crashes. They operate 24
hours a day to ensure traffic is flowing correctly.
Drivers, pedestrians, and bicycle riders must
obey these signals unless an officer is directing
traffic.
Standard Lights
Red — Come to a
complete stop before
the marked stop line
and before moving into the crosswalk or
intersection. After a complete stop, you may
turn right on red at most intersections if the
way is clear. Some intersections display a "NO
TURN ON RED" sign, which means you may
not turn until the light is green. In many areas,
left turns on red from a one-way street into a
one-way street also are allowed.
Yellow — Clear the intersection or stop if you
can, as the light will soon be red.
Green — Go, but only if the intersection is
clear. Yield to pedestrians and vehicles still in
the intersection.
Arrows
Red — Come to a complete stop before the
marked stop line.
8

Yellow — The yellow arrow means
the same as the yellow light, but
applies only to movement in the
direction of the arrow.
Green — A green arrow, pointing
right or left, means you may make a
turn in that direction. If the light is
red at the same time, you must be in
the proper lane for such a turn, and
you must yield the right-of-way to
vehicles and pedestrians within the intersection.
Flashing
Red — A flashing red light should
be treated as a stop sign. Come to a
complete stop and proceed with
caution.
Yellow — A flashing yellow light
means you may move forward with
caution. A yellow flashing light also
is used to alert you to a warning
sign such as a school crossing or sharp curve.
Note: When approaching an
intersection with an inoperative traffic
signal, treat the light as a stop sign.
Pedestrian Crossings
At many intersections, pedestrians share the
road with motorists. Getting across the street
safely may be a nerve-racking situation, but
signals will show you the way. Some signals use
the words “walk” and “don’t walk.” Others use
symbols to indicate the same instructions.
Another device being used in many localities is
the countdown pedestrian signal. Countdown
pedestrian signals take the guesswork out of
pedestrians crossing by letting them know
exactly how long they have to cross an
9

intersection by displaying a countdown of the
number of seconds the pedestrian has left to
cross. This is very useful because mobility
impaired pedestrians now can determine if they
have an adequate period of time to complete a
safe crossing.
These words, symbols and countdown devices
use color and/or a flashing message to
communicate with pedestrians and motorists.
At some intersections, you also may hear a
sound that indicates to visually impaired
pedestrians when they may cross safely.
• Steady white
words or symbols are
"permissive." You are
permitted to enter and cross the street in the
crosswalk area.
• Flashing orange
words or symbols
warn that permitted
crossing is ending
while the countdown device indicates the
number of seconds the pedestrian has left to
cross safely. Pedestrians in the street should
continue to the other side or to a safety
island. Pedestrians still on the curb should not
try to cross because there is not enough time.
• Steady orange
words or symbols are
"restrictive." You are
not permitted to
leave the curb or cross the street.
Pedestrians are no match for a car, so make
sure you look both ways and use caution – even
when the signals allow you to cross the street.
Watch for vehicles turning right on red. When
the “don’t walk” signal begins flashing, do not
panic. If you have started crossing, continue
quickly and with caution. If you need to cross
10

an intersection that does not have pedestrian
signals, watch the main traffic signal. Wait until
traffic going in the direction you want to go has
a green signal before you begin to cross. Cross
with caution and watch for turning vehicles.
Pavement Markings
Pavement markings separate opposing streams
of traffic and direct vehicles into proper
positions on the roadway. For example,
pavement markings define turn lanes at
intersections and establish no-passing zones.
White and yellow paint is customarily used
along pavement edges and between lanes to
keep vehicles in line. These lines may be solid or
broken (long dashes), single or double. Unless
you are turning, exiting a highway, or changing
lanes, you should keep your vehicle between the
lines marking your lane.
Yellow Lane Lines
Yellow lane lines separate lanes of traffic
moving in opposite directions. Single yellow
lines also may be used to mark the left edge of
the pavement on divided highways and one-way
streets.
• A broken yellow line
separates lanes of traffic
moving in opposite
directions. You should
stay to the right of the
line unless you are
passing a vehicle in front
of you. When passing,
you may cross this line temporarily when it is
safe to do so.
• Double yellow lines: One solid, one
broken. A solid yellow line to the right of a
broken yellow center line means passing or
crossing is prohibited in that lane, except
11

when turning left. If the
broken line is closer to
you, then you may cross
the broken line only to
pass another vehicle and
only when it is safe to
do so.
• Double, solid yellow
lines prohibit vehicles
moving in either direction
from crossing the lines.
You may not cross these
lines unless turning left
when it is safe to do so.
White Lane Lines
White lane lines separate lanes of traffic moving
in the same direction. Single white lines also
may be used to mark the right edge of the
pavement.
• A broken
white line
separate lines
of traffic going
in the same
direction. They
may be
crossed with
care.
• A solid white
line marks the
edge of the
roadway or
separates lanes
of traffic moving
in the same
direction. You
may travel in the same direction on both
sides of this line, but you should not cross the
line unless you must do so to avoid a hazard.
12

• Double solid
white lines
indicate that
changing lanes
is not allowed.
• Solid with
turn lane
arrow
- Solid white
lines are
used for
turn lanes
and to
discourage
lane changes
near intersections. Arrows are often used
with the white lines to show which turn
may be made from the lane.
- If you are in a lane marked with a curved
arrow and the word “only,” you must turn
in the direction of the arrow. If your lane is
marked with both a curved and straight
arrow, you may either turn or go straight.
We all share the road and we must
cooperate with others. Highway signs,
signals, and markings communicate
with us about using the road
appropriately. For your safety and the
safety of others, make sure you know
how to "read" the traffic control
devices and understand what they are
telling you. Traffic control devices are
put in place to help you stay alert and
stay alive.
This brochure is intended to be used for informational
purposes only. It is not intended to be a comprehensive
standard or guideline for the use or placement of traffic
control devices.
13

Provided as a public service
by your AAA club.
For more information about
AAA Traffic Safety Programs,
contact your local AAA club's
Traffic Safety Department
or visit www.aaa.com.
Traffic Safety Programs
1000 AAA Drive
Heathrow, Florida
32746-5063
www.aaa.com • 1-800-JOIN-AAA
Stock Number 3556 Copyright ©2005 AAA. All rights reserved. Printed in the U.S.A. October 2005