Transcript Traffic Terms

Traffic Vocabulary and Definitions
The funny thing about driving your car off a cliff, I bet you're still hitting those brakes.
– Jack Handey
Absolute Speed Limit

The maximum or minimum posted speed
at which one may drive under normal
conditions in good weather.
Acceleration Lane

A lane used by drivers entering the
expressway to pick up speed so they can
merge with expressway traffic.
Accelerator Pedal

Controls the flow of fuel to the engine and
regulates speed.
Actual Physical Control

A person can be charged with DUI of
alcohol or some other drug if they have the
ability to move their vehicle.
Advisory Speed Limit

A speed limit that advises drivers that an
adjusted speed is necessary for a short
period of time.
Anti-lock Braking Systems (ABS)

A vehicle braking system that is designed
to keep a vehicle’s wheel from locking
when brakes are applied with greater than
normal force.
Basic Speed Law

Any speed under the absolute limit that is
safe for existing road, weather, or traffic
conditions.
Blind Spot

Areas to the sides and rear of the vehicle
that the driver cannot see with the use of
either side or rear view mirrors.
Blood Alcohol Concentration (BAC)

The percentage of alcohol found in a person’s blood at
any given time. In addition, BAC is how law enforcement
measures the level of intoxication in a person. (Alabama
BAC limit for underage persons .02%, 21 and older
.08%)
Carbon Monoxide

A highly poisonous gas that is given off by burning fossil
fuel. It is colorless and odorless.
 Note: Many people die each year from breathing this
gas. Most are teens or young adults sitting in parked
vehicles.
Centrifugal Force

A natural law that tends to push a vehicle
out of a curve and into a straight path.
Contrast Sensitivity

The ability to see under difficult conditions
such as glare from oncoming headlights,
heavy snow conditions, and even driving
at night.
Cover the Brake

Take your foot off the accelerator and hold
it over the brake pedal to be ready to
brake quickly.
Driving Under the Influence (DUI)

Driving under the influence of any mind altering drug.
This includes alcohol, prescription and non-prescription
drugs, marijuana, hallucinogenic drugs, and any other
drugs that alter the brain.
 In Alabama you can be arrested and taken to jail for a
BAC of .05% even when the legal limit for adults (21
and over) is .08%
Fresh/ Stale Green Light
Fresh Green Light- light has just turned
from red to green
 Stale Green Light- light that has been
green for a long time

Hand Position

Refers to hand placement on
the steering wheel while
driving
 Hand-over-hand steering–
method where hands cross
over each other while
turning
 Push-pull-feed steering–
method where hands do
not cross while turning
(used with airbags)
 “9 and 3” or “10 and 2”–
refers to hand placement
while driving
Highway Hypnosis


A trance-like state of drowsiness that can occur with little
warning, usually occurs after long hours behind the
wheel caused by concentration on the road ahead and
the monotony of driving
To fight highway hypnosis it is recommended to stop and
walk around your vehicle every 100 miles or 2 hours.
Hydroplaning

Condition in which the tires of a moving
vehicle ride on a cushion of water causing
loss of control in both steering and braking
Implied Consent

The law stating that any licensed driver
cannot legally refuse to be tested for
alcohol or drug use while behind the wheel
or in “actual physical control” of a vehicle.
You give consent when you sign your
license
Overdrive

At speeds of 40-45 mph the vehicle automatically shifts
into overdrive. Driving in this gear saves fuel and can be
used for all normal driving conditions.
Over-driving your headlights

Driving so fast at night that a driver is
unable to stop within the range of their
headlights
SIPDE

The basic principles of defensive driving.
The letters stand for:
Space Margin
A cushion of space a driver tries to maintain around their
vehicle. Space margin distance increases as speed goes
up.
Note: A safe following distance for good weather is about
two (2) seconds behind the vehicle in front of you. As the
weather becomes worse, your space margin should
increase.

Stop Bar

The white line painted
on the road where a
stop is required. They
are most commonly
found at intersections.
DO NOT CROSS
Total Stopping Distance
The distance to bring a vehicle to a
complete stop from the time of perception
until the wheels actually stop rolling.
Note: At 60 mph a vehicle equipped with
good tires and brakes travels almost 300
feet from the time you see the conflict until
you actually bring the vehicle to a stop.

Uncontrolled Stop

Usually in a neighborhood, this is where a
stop is required but there is no sign.
Velocitizing
The sensation of moving more slowly than one actually
is as a result of driving at a fast speed for a long period
of time.
Example: Leaving the freeway and moving to a surface
street with a speed limit of 35 mph. As a result traveling
at the speed limit may seem much slower.
